Merge branch 'linus' into stackprotector

Conflicts:
	arch/x86/include/asm/pda.h
	kernel/fork.c

.mailmap

@@ -66,6 +66,7 @@ Kenneth W Chen <kenneth.w.chen@intel.com>
 Koushik <raghavendra.koushik@neterion.com>
 Leonid I Ananiev <leonid.i.ananiev@intel.com>
 Linas Vepstas <linas@austin.ibm.com>
+Mark Brown <broonie@sirena.org.uk>
 Matthieu CASTET <castet.matthieu@free.fr>
 Michael Buesch <mb@bu3sch.de>
 Michael Buesch <mbuesch@freenet.de>
@@ -79,6 +80,8 @@ Nguyen Anh Quynh <aquynh@gmail.com>
 Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
 Patrick Mochel <mochel@digitalimplant.org>
 Peter A Jonsson <pj@ludd.ltu.se>
+Peter Oruba <peter@oruba.de>
+Peter Oruba <peter.oruba@amd.com>
 Praveen BP <praveenbp@ti.com>
 Rajesh Shah <rajesh.shah@intel.com>
 Ralf Baechle <ralf@linux-mips.org>

CREDITS

@@ -598,6 +598,11 @@ S: Tamsui town, Taipei county,
 S: Taiwan 251
 S: Republic of China
 
+N: Reinette Chatre
+E: reinette.chatre@intel.com
+D: WiMedia Link Protocol implementation
+D: UWB stack bits and pieces
+
 N: Michael Elizabeth Chastain
 E: mec@shout.net
 D: Configure, Menuconfig, xconfig
@@ -1653,14 +1658,14 @@ S: Chapel Hill, North Carolina 27514-4818
 S: USA
 
 N: Dave Jones
-E: davej@codemonkey.org.uk
+E: davej@redhat.com
 W: http://www.codemonkey.org.uk
-D: x86 errata/setup maintenance.
-D: AGPGART driver.
+D: Assorted VIA x86 support.
+D: 2.5 AGPGART overhaul.
 D: CPUFREQ maintenance.
-D: Backport/Forwardport merge monkey.
-D: Various Janitor work.
-S: United Kingdom
+D: Fedora kernel maintainence.
+D: Misc/Other.
+S: 314 Littleton Rd, Westford, MA 01886, USA
 
 N: Martin Josfsson
 E: gandalf@wlug.westbo.se
@@ -2695,6 +2700,12 @@ S: Demonstratsii 8-382
 S: Tula 300000
 S: Russia
 
+N: Inaky Perez-Gonzalez
+E: inaky.perez-gonzalez@intel.com
+D: UWB stack, HWA-RC driver and HWA-HC drivers
+D: Wireless USB additions to the USB stack
+D: WiMedia Link Protocol bits and pieces
+
 N: Gordon Peters
 E: GordPeters@smarttech.com
 D: Isochronous receive for IEEE 1394 driver (OHCI module).

Documentation/00-INDEX

@@ -21,6 +21,9 @@ Changes
 	- list of changes that break older software packages.
 CodingStyle
 	- how the boss likes the C code in the kernel to look.
+development-process/
+	- An extended tutorial on how to work with the kernel development
+	  process.
 DMA-API.txt
 	- DMA API, pci_ API & extensions for non-consistent memory machines.
 DMA-ISA-LPC.txt
@@ -39,14 +42,8 @@ IRQ.txt
 	- description of what an IRQ is.
 ManagementStyle
 	- how to (attempt to) manage kernel hackers.
-MSI-HOWTO.txt
-	- the Message Signaled Interrupts (MSI) Driver Guide HOWTO and FAQ.
 RCU/
 	- directory with info on RCU (read-copy update).
-README.DAC960
-	- info on Mylex DAC960/DAC1100 PCI RAID Controller Driver for Linux.
-README.cycladesZ
-	- info on Cyclades-Z firmware loading.
 SAK.txt
 	- info on Secure Attention Keys.
 SM501.txt
@@ -83,20 +80,16 @@ blackfin/
 	- directory with documentation for the Blackfin arch.
 block/
 	- info on the Block I/O (BIO) layer.
+blockdev/
+	- info on block devices & drivers
 cachetlb.txt
 	- describes the cache/TLB flushing interfaces Linux uses.
-cciss.txt
-	- info, major/minor #'s for Compaq's SMART Array Controllers.
 cdrom/
 	- directory with information on the CD-ROM drivers that Linux has.
-computone.txt
-	- info on Computone Intelliport II/Plus Multiport Serial Driver.
 connector/
 	- docs on the netlink based userspace<->kernel space communication mod.
 console/
 	- documentation on Linux console drivers.
-cpqarray.txt
-	- info on using Compaq's SMART2 Intelligent Disk Array Controllers.
 cpu-freq/
 	- info on CPU frequency and voltage scaling.
 cpu-hotplug.txt
@@ -123,8 +116,6 @@ device-mapper/
 	- directory with info on Device Mapper.
 devices.txt
 	- plain ASCII listing of all the nodes in /dev/ with major minor #'s.
-digiepca.txt
-	- info on Digi Intl. {PC,PCI,EISA}Xx and Xem series cards.
 dontdiff
 	- file containing a list of files that should never be diff'ed.
 driver-model/
@@ -149,14 +140,10 @@ filesystems/
 	- info on the vfs and the various filesystems that Linux supports.
 firmware_class/
 	- request_firmware() hotplug interface info.
-floppy.txt
-	- notes and driver options for the floppy disk driver.
 frv/
 	- Fujitsu FR-V Linux documentation.
 gpio.txt
 	- overview of GPIO (General Purpose Input/Output) access conventions.
-hayes-esp.txt
-	- info on using the Hayes ESP serial driver.
 highuid.txt
 	- notes on the change from 16 bit to 32 bit user/group IDs.
 timers/
@@ -169,7 +156,7 @@ i2c/
 	- directory with info about the I2C bus/protocol (2 wire, kHz speed).
 i2o/
 	- directory with info about the Linux I2O subsystem.
-i386/
+x86/i386/
 	- directory with info about Linux on Intel 32 bit architecture.
 ia64/
 	- directory with info about Linux on Intel 64 bit architecture.
@@ -183,8 +170,6 @@ io_ordering.txt
 	- info on ordering I/O writes to memory-mapped addresses.
 ioctl/
 	- directory with documents describing various IOCTL calls.
-ioctl-number.txt
-	- how to implement and register device/driver ioctl calls.
 iostats.txt
 	- info on I/O statistics Linux kernel provides.
 irqflags-tracing.txt
@@ -247,14 +232,10 @@ mips/
 	- directory with info about Linux on MIPS architecture.
 mono.txt
 	- how to execute Mono-based .NET binaries with the help of BINFMT_MISC.
-moxa-smartio
-	- file with info on installing/using Moxa multiport serial driver.
 mutex-design.txt
 	- info on the generic mutex subsystem.
 namespaces/
 	- directory with various information about namespaces
-nbd.txt
-	- info on a TCP implementation of a network block device.
 netlabel/
 	- directory with information on the NetLabel subsystem.
 networking/
@@ -267,8 +248,6 @@ numastat.txt
 	- info on how to read Numa policy hit/miss statistics in sysfs.
 oops-tracing.txt
 	- how to decode those nasty internal kernel error dump messages.
-paride.txt
-	- information about the parallel port IDE subsystem.
 parisc/
 	- directory with info on using Linux on PA-RISC architecture.
 parport.txt
@@ -287,20 +266,16 @@ powerpc/
 	- directory with info on using Linux with the PowerPC.
 preempt-locking.txt
 	- info on locking under a preemptive kernel.
+printk-formats.txt
+	- how to get printk format specifiers right
 prio_tree.txt
 	- info on radix-priority-search-tree use for indexing vmas.
-ramdisk.txt
-	- short guide on how to set up and use the RAM disk.
 rbtree.txt
 	- info on what red-black trees are and what they are for.
-riscom8.txt
-	- notes on using the RISCom/8 multi-port serial driver.
 robust-futex-ABI.txt
 	- documentation of the robust futex ABI.
 robust-futexes.txt
 	- a description of what robust futexes are.
-rocket.txt
-	- info on the Comtrol RocketPort multiport serial driver.
 rt-mutex-design.txt
 	- description of the RealTime mutex implementation design.
 rt-mutex.txt
@@ -329,8 +304,6 @@ sparc/
 	- directory with info on using Linux on Sparc architecture.
 sparse.txt
 	- info on how to obtain and use the sparse tool for typechecking.
-specialix.txt
-	- info on hardware/driver for specialix IO8+ multiport serial card.
 spi/
 	- overview of Linux kernel Serial Peripheral Interface (SPI) support.
 spinlocks.txt
@@ -339,14 +312,10 @@ stable_api_nonsense.txt
 	- info on why the kernel does not have a stable in-kernel api or abi.
 stable_kernel_rules.txt
 	- rules and procedures for the -stable kernel releases.
-stallion.txt
-	- info on using the Stallion multiport serial driver.
 svga.txt
 	- short guide on selecting video modes at boot via VGA BIOS.
 sysfs-rules.txt
 	- How not to use sysfs.
-sx.txt
-	- info on the Specialix SX/SI multiport serial driver.
 sysctl/
 	- directory with info on the /proc/sys/* files.
 sysrq.txt
@@ -355,8 +324,6 @@ telephony/
 	- directory with info on telephony (e.g. voice over IP) support.
 time_interpolators.txt
 	- info on time interpolators.
-tty.txt
-	- guide to the locking policies of the tty layer.
 uml/
 	- directory with information about User Mode Linux.
 unicode.txt
@@ -379,7 +346,7 @@ w1/
 	- directory with documents regarding the 1-wire (w1) subsystem.
 watchdog/
 	- how to auto-reboot Linux if it has "fallen and can't get up". ;-)
-x86_64/
+x86/x86_64/
 	- directory with info on Linux support for AMD x86-64 (Hammer) machines.
 zorro.txt
 	- info on writing drivers for Zorro bus devices found on Amigas.

Documentation/ABI/stable/sysfs-driver-usb-usbtmc

@@ -0,0 +1,62 @@
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/interface_capabilities
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/device_capabilities
+Date:		August 2008
+Contact:	Greg Kroah-Hartman <gregkh@suse.de>
+Description:
+		These files show the various USB TMC capabilities as described
+		by the device itself.  The full description of the bitfields
+		can be found in the USB TMC documents from the USB-IF entitled
+		"Universal Serial Bus Test and Measurement Class Specification
+		(USBTMC) Revision 1.0" section 4.2.1.8.
+
+		The files are read only.
+
+
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/usb488_interface_capabilities
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/usb488_device_capabilities
+Date:		August 2008
+Contact:	Greg Kroah-Hartman <gregkh@suse.de>
+Description:
+		These files show the various USB TMC capabilities as described
+		by the device itself.  The full description of the bitfields
+		can be found in the USB TMC documents from the USB-IF entitled
+		"Universal Serial Bus Test and Measurement Class, Subclass
+		USB488 Specification (USBTMC-USB488) Revision 1.0" section
+		4.2.2.
+
+		The files are read only.
+
+
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/TermChar
+Date:		August 2008
+Contact:	Greg Kroah-Hartman <gregkh@suse.de>
+Description:
+		This file is the TermChar value to be sent to the USB TMC
+		device as described by the document, "Universal Serial Bus Test
+		and Measurement Class Specification
+		(USBTMC) Revision 1.0" as published by the USB-IF.
+
+		Note that the TermCharEnabled file determines if this value is
+		sent to the device or not.
+
+
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/TermCharEnabled
+Date:		August 2008
+Contact:	Greg Kroah-Hartman <gregkh@suse.de>
+Description:
+		This file determines if the TermChar is to be sent to the
+		device on every transaction or not.  For more details about
+		this, please see the document, "Universal Serial Bus Test and
+		Measurement Class Specification (USBTMC) Revision 1.0" as
+		published by the USB-IF.
+
+
+What:		/sys/bus/usb/drivers/usbtmc/devices/*/auto_abort
+Date:		August 2008
+Contact:	Greg Kroah-Hartman <gregkh@suse.de>
+Description:
+		This file determines if the the transaction of the USB TMC
+		device is to be automatically aborted if there is any error.
+		For more details about this, please see the document,
+		"Universal Serial Bus Test and Measurement Class Specification
+		(USBTMC) Revision 1.0" as published by the USB-IF.

Documentation/ABI/testing/sysfs-bus-umc

@@ -0,0 +1,28 @@
+What:           /sys/bus/umc/
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The Wireless Host Controller Interface (WHCI)
+                specification describes a PCI-based device with
+                multiple capabilities; the UWB Multi-interface
+                Controller (UMC).
+
+                The umc bus presents each of the individual
+                capabilties as a device.
+
+What:           /sys/bus/umc/devices/.../capability_id
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The ID of this capability, with 0 being the radio
+                controller capability.
+
+What:           /sys/bus/umc/devices/.../version
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The specification version this capability's hardware
+                interface complies with.

Documentation/ABI/testing/sysfs-bus-usb

@@ -85,3 +85,62 @@ Description:
 Users:
 		PowerTOP <power@bughost.org>
 		http://www.lesswatts.org/projects/powertop/
+
+What:		/sys/bus/usb/device/<busnum>-<devnum>...:<config num>-<interface num>/supports_autosuspend
+Date:		January 2008
+KernelVersion:	2.6.27
+Contact:	Sarah Sharp <sarah.a.sharp@intel.com>
+Description:
+		When read, this file returns 1 if the interface driver
+		for this interface supports autosuspend.  It also
+		returns 1 if no driver has claimed this interface, as an
+		unclaimed interface will not stop the device from being
+		autosuspended if all other interface drivers are idle.
+		The file returns 0 if autosuspend support has not been
+		added to the driver.
+Users:
+		USB PM tool
+		git://git.moblin.org/users/sarah/usb-pm-tool/
+
+What:		/sys/bus/usb/device/.../authorized
+Date:		July 2008
+KernelVersion:	2.6.26
+Contact:	David Vrabel <david.vrabel@csr.com>
+Description:
+		Authorized devices are available for use by device
+		drivers, non-authorized one are not.  By default, wired
+		USB devices are authorized.
+
+		Certified Wireless USB devices are not authorized
+		initially and should be (by writing 1) after the
+		device has been authenticated.
+
+What:		/sys/bus/usb/device/.../wusb_cdid
+Date:		July 2008
+KernelVersion:	2.6.27
+Contact:	David Vrabel <david.vrabel@csr.com>
+Description:
+		For Certified Wireless USB devices only.
+
+		A devices's CDID, as 16 space-separated hex octets.
+
+What:		/sys/bus/usb/device/.../wusb_ck
+Date:		July 2008
+KernelVersion:	2.6.27
+Contact:	David Vrabel <david.vrabel@csr.com>
+Description:
+		For Certified Wireless USB devices only.
+
+		Write the device's connection key (CK) to start the
+		authentication of the device.  The CK is 16
+		space-separated hex octets.
+
+What:		/sys/bus/usb/device/.../wusb_disconnect
+Date:		July 2008
+KernelVersion:	2.6.27
+Contact:	David Vrabel <david.vrabel@csr.com>
+Description:
+		For Certified Wireless USB devices only.
+
+		Write a 1 to force the device to disconnect
+		(equivalent to unplugging a wired USB device).

Documentation/ABI/testing/sysfs-bus-usb-devices-usbsevseg

@@ -0,0 +1,43 @@
+Where:		/sys/bus/usb/.../powered
+Date:		August 2008
+Kernel Version:	2.6.26
+Contact:	Harrison Metzger <harrisonmetz@gmail.com>
+Description:	Controls whether the device's display will powered.
+		A value of 0 is off and a non-zero value is on.
+
+Where:		/sys/bus/usb/.../mode_msb
+Where:		/sys/bus/usb/.../mode_lsb
+Date:		August 2008
+Kernel Version:	2.6.26
+Contact:	Harrison Metzger <harrisonmetz@gmail.com>
+Description:	Controls the devices display mode.
+		For a 6 character display the values are
+			MSB 0x06; LSB 0x3F, and
+		for an 8 character display the values are
+			MSB 0x08; LSB 0xFF.
+
+Where:		/sys/bus/usb/.../textmode
+Date:		August 2008
+Kernel Version:	2.6.26
+Contact:	Harrison Metzger <harrisonmetz@gmail.com>
+Description:	Controls the way the device interprets its text buffer.
+		raw:	each character controls its segment manually
+		hex:	each character is between 0-15
+		ascii:	each character is between '0'-'9' and 'A'-'F'.
+
+Where:		/sys/bus/usb/.../text
+Date:		August 2008
+Kernel Version:	2.6.26
+Contact:	Harrison Metzger <harrisonmetz@gmail.com>
+Description:	The text (or data) for the device to display
+
+Where:		/sys/bus/usb/.../decimals
+Date:		August 2008
+Kernel Version:	2.6.26
+Contact:	Harrison Metzger <harrisonmetz@gmail.com>
+Description:	Controls the decimal places on the device.
+		To set the nth decimal place, give this field
+		the value of 10 ** n. Assume this field has
+		the value k and has 1 or more decimal places set,
+		to set the mth place (where m is not already set),
+		change this fields value to k + 10 ** m.

Documentation/ABI/testing/sysfs-c2port

@@ -0,0 +1,88 @@
+What:		/sys/class/c2port/
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/ directory will contain files and
+		directories that will provide a unified interface to
+		the C2 port interface.
+
+What:		/sys/class/c2port/c2portX
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/ directory is related to X-th
+		C2 port into the system. Each directory will contain files to
+		manage and control its C2 port.
+
+What:		/sys/class/c2port/c2portX/access
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/access file enable the access
+		to the C2 port from the system. No commands can be sent
+		till this entry is set to 0.
+
+What:		/sys/class/c2port/c2portX/dev_id
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/dev_id file show the device ID
+		of the connected micro.
+
+What:		/sys/class/c2port/c2portX/flash_access
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/flash_access file enable the
+		access to the on-board flash of the connected micro.
+		No commands can be sent till this entry is set to 0.
+
+What:		/sys/class/c2port/c2portX/flash_block_size
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/flash_block_size file show
+		the on-board flash block size of the connected micro.
+
+What:		/sys/class/c2port/c2portX/flash_blocks_num
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/flash_blocks_num file show
+		the on-board flash blocks number of the connected micro.
+
+What:		/sys/class/c2port/c2portX/flash_data
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/flash_data file export
+		the content of the on-board flash of the connected micro.
+
+What:		/sys/class/c2port/c2portX/flash_erase
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/flash_erase file execute
+		the "erase" command on the on-board flash of the connected
+		micro.
+
+What:		/sys/class/c2port/c2portX/flash_erase
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/flash_erase file show the
+		on-board flash size of the connected micro.
+
+What:		/sys/class/c2port/c2portX/reset
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/reset file execute a "reset"
+		command on the connected micro.
+
+What:		/sys/class/c2port/c2portX/rev_id
+Date:		October 2008
+Contact:	Rodolfo Giometti <giometti@linux.it>
+Description:
+		The /sys/class/c2port/c2portX/rev_id file show the revision ID
+		of the connected micro.

Documentation/ABI/testing/sysfs-class-usb_host

@@ -0,0 +1,25 @@
+What:           /sys/class/usb_host/usb_hostN/wusb_chid
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                Write the CHID (16 space-separated hex octets) for this host controller.
+                This starts the host controller, allowing it to accept connection from
+                WUSB devices.
+
+                Set an all zero CHID to stop the host controller.
+
+What:           /sys/class/usb_host/usb_hostN/wusb_trust_timeout
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                Devices that haven't sent a WUSB packet to the host
+                within 'wusb_trust_timeout' ms are considered to have
+                disconnected and are removed.  The default value of
+                4000 ms is the value required by the WUSB
+                specification.
+
+                Since this relates to security (specifically, the
+                lifetime of PTKs and GTKs) it should not be changed
+                from the default.

Documentation/ABI/testing/sysfs-class-uwb_rc

@@ -0,0 +1,144 @@
+What:           /sys/class/uwb_rc
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                Interfaces for WiMedia Ultra Wideband Common Radio
+                Platform (UWB) radio controllers.
+
+                Familiarity with the ECMA-368 'High Rate Ultra
+                Wideband MAC and PHY Specification' is assumed.
+
+What:           /sys/class/uwb_rc/beacon_timeout_ms
+Date:           July 2008
+KernelVersion:  2.6.27
+Description:
+                If no beacons are received from a device for at least
+                this time, the device will be considered to have gone
+                and it will be removed.  The default is 3 superframes
+                (~197 ms) as required by the specification.
+
+What:           /sys/class/uwb_rc/uwbN/
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                An individual UWB radio controller.
+
+What:           /sys/class/uwb_rc/uwbN/beacon
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                Write:
+
+                <channel> [<bpst offset>]
+
+                to start beaconing on a specific channel, or stop
+                beaconing if <channel> is -1.  Valid channels depends
+                on the radio controller's supported band groups.
+
+                <bpst offset> may be used to try and join a specific
+                beacon group if more than one was found during a scan.
+
+What:           /sys/class/uwb_rc/uwbN/scan
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                Write:
+
+                <channel> <type> [<bpst offset>]
+
+                to start (or stop) scanning on a channel.  <type> is one of:
+                    0 - scan
+                    1 - scan outside BP
+                    2 - scan while inactive
+                    3 - scanning disabled
+                    4 - scan (with start time of <bpst offset>)
+
+What:           /sys/class/uwb_rc/uwbN/mac_address
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                The EUI-48, in colon-separated hex octets, for this
+                radio controller.  A write will change the radio
+                controller's EUI-48 but only do so while the device is
+                not beaconing or scanning.
+
+What:           /sys/class/uwb_rc/uwbN/wusbhc
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                A symlink to the device (if any) of the WUSB Host
+                Controller PAL using this radio controller.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                A neighbour UWB device that has either been detected
+                as part of a scan or is a member of the radio
+                controllers beacon group.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/BPST
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                The time (using the radio controllers internal 1 ms
+                interval superframe timer) of the last beacon from
+                this device was received.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/DevAddr
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                The current DevAddr of this device in colon separated
+                hex octets.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/EUI_48
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+
+                The EUI-48 of this device in colon separated hex
+                octets.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/BPST
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/IEs
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                The latest IEs included in this device's beacon, in
+                space separated hex octets with one IE per line.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/LQE
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                Link Quality Estimate - the Signal to Noise Ratio
+                (SNR) of all packets received from this device in dB.
+                This gives an estimate on a suitable PHY rate. Refer
+                to [ECMA-368] section 13.3 for more details.
+
+What:           /sys/class/uwb_rc/uwbN/<EUI-48>/RSSI
+Date:           July 2008
+KernelVersion:  2.6.27
+Contact:        linux-usb@vger.kernel.org
+Description:
+                Received Signal Strength Indication - the strength of
+                the received signal in dB.  LQE is a more useful
+                measure of the radio link quality.

Documentation/ABI/testing/sysfs-firmware-acpi

@@ -89,7 +89,7 @@ Description:
 
 		error - an interrupt that can't be accounted for above.
 
-		invalid: it's either a wakeup GPE or a GPE/Fixed Event that
+		invalid: it's either a GPE or a Fixed Event that
 			doesn't have an event handler.
 
 		disable: the GPE/Fixed Event is valid but disabled.
@@ -117,30 +117,30 @@ Description:
 		and other user space applications so that the machine won't shutdown
 		when pressing the power button.
 		# cat ff_pwr_btn
-		0
+		0	enabled
 		# press the power button for 3 times;
 		# cat ff_pwr_btn
-		3
+		3	enabled
 		# echo disable > ff_pwr_btn
 		# cat ff_pwr_btn
-		disable
+		3	disabled
 		# press the power button for 3 times;
 		# cat ff_pwr_btn
-		disable
+		3	disabled
 		# echo enable > ff_pwr_btn
 		# cat ff_pwr_btn
-		4
+		4	enabled
 		/*
 		 * this is because the status bit is set even if the enable bit is cleared,
 		 * and it triggers an ACPI fixed event when the enable bit is set again
 		 */
 		# press the power button for 3 times;
 		# cat ff_pwr_btn
-		7
+		7	enabled
 		# echo disable > ff_pwr_btn
 		# press the power button for 3 times;
 		# echo clear > ff_pwr_btn	/* clear the status bit */
 		# echo disable > ff_pwr_btn
 		# cat ff_pwr_btn
-		7
+		7	enabled
 

Documentation/ABI/testing/sysfs-profiling

@@ -0,0 +1,13 @@
+What:		/sys/kernel/profile
+Date:		September 2008
+Contact:	Dave Hansen <dave@linux.vnet.ibm.com>
+Description:
+		/sys/kernel/profile is the runtime equivalent
+		of the boot-time profile= option.
+
+		You can get the same effect running:
+
+			echo 2 > /sys/kernel/profile
+
+		as you would by issuing profile=2 on the boot
+		command line.

Documentation/ABI/testing/sysfs-wusb_cbaf

@@ -0,0 +1,100 @@
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_*
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                Various files for managing Cable Based Association of
+                (wireless) USB devices.
+
+                The sequence of operations should be:
+
+                1. Device is plugged in.
+
+                2. The connection manager (CM) sees a device with CBA capability.
+                   (the wusb_chid etc. files in /sys/devices/blah/OURDEVICE).
+
+                3. The CM writes the host name, supported band groups,
+                   and the CHID (host ID) into the wusb_host_name,
+                   wusb_host_band_groups and wusb_chid files. These
+                   get sent to the device and the CDID (if any) for
+                   this host is requested.
+
+                4. The CM can verify that the device's supported band
+                   groups (wusb_device_band_groups) are compatible
+                   with the host.
+
+                5. The CM reads the wusb_cdid file.
+
+                6. The CM looks it up its database.
+
+                   - If it has a matching CHID,CDID entry, the device
+                     has been authorized before and nothing further
+                     needs to be done.
+
+                   - If the CDID is zero (or the CM doesn't find a
+                     matching CDID in its database), the device is
+                     assumed to be not known.  The CM may associate
+                     the host with device by: writing a randomly
+                     generated CDID to wusb_cdid and then a random CK
+                     to wusb_ck (this uploads the new CC to the
+                     device).
+
+                     CMD may choose to prompt the user before
+                     associating with a new device.
+
+                7. Device is unplugged.
+
+                References:
+                  [WUSB-AM] Association Models Supplement to the
+                            Certified Wireless Universal Serial Bus
+                            Specification, version 1.0.
+
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_chid
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The CHID of the host formatted as 16 space-separated
+                hex octets.
+
+                Writes fetches device's supported band groups and the
+                the CDID for any existing association with this host.
+
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_host_name
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                A friendly name for the host as a UTF-8 encoded string.
+
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_host_band_groups
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The band groups supported by the host, in the format
+                defined in [WUSB-AM].
+
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_device_band_groups
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The band groups supported by the device, in the format
+                defined in [WUSB-AM].
+
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_cdid
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                The device's CDID formatted as 16 space-separated hex
+                octets.
+
+What:           /sys/bus/usb/drivers/wusb_cbaf/.../wusb_ck
+Date:           August 2008
+KernelVersion:  2.6.27
+Contact:        David Vrabel <david.vrabel@csr.com>
+Description:
+                Write 16 space-separated random, hex octets to
+                associate with the device.

Documentation/DMA-API.txt

@@ -316,12 +316,10 @@ reduce current DMA mapping usage or delay and try again later).
 	pci_map_sg(struct pci_dev *hwdev, struct scatterlist *sg,
 		int nents, int direction)
 
-Maps a scatter gather list from the block layer.
-
 Returns: the number of physical segments mapped (this may be shorter
-than <nents> passed in if the block layer determines that some
-elements of the scatter/gather list are physically adjacent and thus
-may be mapped with a single entry).
+than <nents> passed in if some elements of the scatter/gather list are
+physically or virtually adjacent and an IOMMU maps them with a single
+entry).
 
 Please note that the sg cannot be mapped again if it has been mapped once.
 The mapping process is allowed to destroy information in the sg.

Documentation/DocBook/Makefile

@@ -6,7 +6,7 @@
 # To add a new book the only step required is to add the book to the
 # list of DOCBOOKS.
 
-DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
+DOCBOOKS := z8530book.xml mcabook.xml \
 	    kernel-hacking.xml kernel-locking.xml deviceiobook.xml \
 	    procfs-guide.xml writing_usb_driver.xml networking.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \
@@ -136,7 +136,7 @@ quiet_cmd_db2ps = PS      $@
 %.ps : %.xml
 	$(call cmd,db2ps)
 
-quiet_cmd_db2pdf = PDF      $@
+quiet_cmd_db2pdf = PDF     $@
       cmd_db2pdf = $(subst TYPE,pdf, $($(PDF_METHOD)template))
 %.pdf : %.xml
 	$(call cmd,db2pdf)
@@ -148,7 +148,7 @@ build_main_index = rm -rf $(main_idx) && \
 		   echo '<h2>Kernel Version: $(KERNELVERSION)</h2>' >> $(main_idx) && \
 		   cat $(HTML) >> $(main_idx)
 
-quiet_cmd_db2html = HTML   $@
+quiet_cmd_db2html = HTML    $@
       cmd_db2html = xmlto xhtml $(XMLTOFLAGS) -o $(patsubst %.html,%,$@) $< && \
 		echo '<a HREF="$(patsubst %.html,%,$(notdir $@))/index.html"> \
         $(patsubst %.html,%,$(notdir $@))</a><p>' > $@

Documentation/DocBook/deviceiobook.tmpl

@@ -24,7 +24,7 @@
     <surname>Cox</surname>
     <affiliation>
      <address>
-      <email>alan@redhat.com</email>
+      <email>alan@lxorguk.ukuu.org.uk</email>
      </address>
     </affiliation>
    </author>
@@ -316,7 +316,7 @@ CPU B:  spin_unlock_irqrestore(&amp;dev_lock, flags)
 
   <chapter id="pubfunctions">
      <title>Public Functions Provided</title>
-!Iinclude/asm-x86/io_32.h
+!Iarch/x86/include/asm/io_32.h
 !Elib/iomap.c
   </chapter>
 

Documentation/DocBook/gadget.tmpl

@@ -557,6 +557,9 @@ Near-term plans include converting all of them, except for "gadgetfs".
 </para>
 
 !Edrivers/usb/gadget/f_acm.c
+!Edrivers/usb/gadget/f_ecm.c
+!Edrivers/usb/gadget/f_subset.c
+!Edrivers/usb/gadget/f_obex.c
 !Edrivers/usb/gadget/f_serial.c
 
 </sect1>

Documentation/DocBook/kernel-api.tmpl

@@ -45,8 +45,8 @@
      </sect1>
 
      <sect1><title>Atomic and pointer manipulation</title>
-!Iinclude/asm-x86/atomic_32.h
-!Iinclude/asm-x86/unaligned.h
+!Iarch/x86/include/asm/atomic_32.h
+!Iarch/x86/include/asm/unaligned.h
      </sect1>
 
      <sect1><title>Delaying, scheduling, and timer routines</title>
@@ -119,7 +119,7 @@ X!Ilib/string.c
 !Elib/string.c
      </sect1>
      <sect1><title>Bit Operations</title>
-!Iinclude/asm-x86/bitops.h
+!Iarch/x86/include/asm/bitops.h
      </sect1>
   </chapter>
 
@@ -155,7 +155,7 @@ X!Ilib/string.c
 !Emm/slab.c
      </sect1>
      <sect1><title>User Space Memory Access</title>
-!Iinclude/asm-x86/uaccess_32.h
+!Iarch/x86/include/asm/uaccess_32.h
 !Earch/x86/lib/usercopy_32.c
      </sect1>
      <sect1><title>More Memory Management Functions</title>
@@ -265,7 +265,7 @@ X!Earch/x86/kernel/mca_32.c
 -->
 	</sect2>
 	<sect2><title>MCA Bus DMA</title>
-!Iinclude/asm-x86/mca_dma.h
+!Iarch/x86/include/asm/mca_dma.h
 	</sect2>
      </sect1>
   </chapter>

Documentation/DocBook/kernel-hacking.tmpl

@@ -1105,7 +1105,7 @@ static struct block_device_operations opt_fops = {
     </listitem>
     <listitem>
      <para>
-      Function names as strings (__FUNCTION__).
+      Function names as strings (__func__).
      </para>
     </listitem>
     <listitem>
@@ -1239,7 +1239,7 @@ static struct block_device_operations opt_fops = {
   </para>
 
   <para>
-   <filename>include/asm-x86/delay_32.h:</filename>
+   <filename>arch/x86/include/asm/delay.h:</filename>
   </para>
   <programlisting>
 #define ndelay(n) (__builtin_constant_p(n) ? \
@@ -1265,7 +1265,7 @@ static struct block_device_operations opt_fops = {
 </programlisting>
 
   <para>
-   <filename>include/asm-x86/uaccess_32.h:</filename>
+   <filename>arch/x86/include/asm/uaccess_32.h:</filename>
   </para>
 
   <programlisting>

Documentation/DocBook/mcabook.tmpl

@@ -12,7 +12,7 @@
     <surname>Cox</surname>
     <affiliation>
      <address>
-      <email>alan@redhat.com</email>
+      <email>alan@lxorguk.ukuu.org.uk</email>
      </address>
     </affiliation>
    </author>
@@ -101,7 +101,7 @@
 
   <chapter id="dmafunctions">
      <title>DMA Functions Provided</title>
-!Iinclude/asm-x86/mca_dma.h
+!Iarch/x86/include/asm/mca_dma.h
   </chapter>
 
 </book>

Documentation/DocBook/networking.tmpl

@@ -98,9 +98,6 @@
 X!Enet/core/wireless.c
      </sect1>
 -->
-     <sect1><title>Synchronous PPP</title>
-!Edrivers/net/wan/syncppp.c
-     </sect1>
   </chapter>
 
 </book>

Documentation/DocBook/procfs-guide.tmpl

@@ -14,17 +14,20 @@
 	<othername>(J.A.K.)</othername>
 	<surname>Mouw</surname>
 	<affiliation>
-	  <orgname>Delft University of Technology</orgname>
-	  <orgdiv>Faculty of Information Technology and Systems</orgdiv>
 	  <address>
-            <email>J.A.K.Mouw@its.tudelft.nl</email>
-            <pob>PO BOX 5031</pob>
-            <postcode>2600 GA</postcode>
-            <city>Delft</city>
-            <country>The Netherlands</country>
+            <email>mouw@nl.linux.org</email>
           </address>
 	</affiliation>
       </author>
+      <othercredit>
+	<contrib>
+	This software and documentation were written while working on the
+	LART computing board
+	(<ulink url="http://www.lartmaker.nl/">http://www.lartmaker.nl/</ulink>),
+	which was sponsored by the Delt University of Technology projects
+	Mobile Multi-media Communications and Ubiquitous Communications.
+	</contrib>
+      </othercredit>
     </authorgroup>
 
     <revhistory>
@@ -108,18 +111,6 @@
       proofreading.
     </para>
 
-    <para>
-      This documentation was written while working on the LART
-      computing board (<ulink
-      url="http://www.lart.tudelft.nl/">http://www.lart.tudelft.nl/</ulink>),
-      which is sponsored by the Mobile Multi-media Communications
-      (<ulink
-      url="http://www.mmc.tudelft.nl/">http://www.mmc.tudelft.nl/</ulink>)
-      and Ubiquitous Communications (<ulink
-      url="http://www.ubicom.tudelft.nl/">http://www.ubicom.tudelft.nl/</ulink>)
-      projects.
-    </para>
-
     <para>
       Erik
     </para>

Documentation/DocBook/procfs_example.c

@@ -1,28 +1,16 @@
 /*
  * procfs_example.c: an example proc interface
  *
- * Copyright (C) 2001, Erik Mouw (J.A.K.Mouw@its.tudelft.nl)
+ * Copyright (C) 2001, Erik Mouw (mouw@nl.linux.org)
  *
  * This file accompanies the procfs-guide in the Linux kernel
  * source. Its main use is to demonstrate the concepts and
  * functions described in the guide.
  *
  * This software has been developed while working on the LART
- * computing board (http://www.lart.tudelft.nl/), which is
- * sponsored by the Mobile Multi-media Communications
- * (http://www.mmc.tudelft.nl/) and Ubiquitous Communications 
- * (http://www.ubicom.tudelft.nl/) projects.
- *
- * The author can be reached at:
- *
- *  Erik Mouw
- *  Information and Communication Theory Group
- *  Faculty of Information Technology and Systems
- *  Delft University of Technology
- *  P.O. Box 5031
- *  2600 GA Delft
- *  The Netherlands
- *
+ * computing board (http://www.lartmaker.nl), which was sponsored
+ * by the Delt University of Technology projects Mobile Multi-media
+ * Communications and Ubiquitous Communications.
  *
  * This program is free software; you can redistribute
  * it and/or modify it under the terms of the GNU General

Documentation/DocBook/videobook.tmpl

@@ -1,1654 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
-	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
-
-<book id="V4LGuide">
- <bookinfo>
-  <title>Video4Linux Programming</title>
-  
-  <authorgroup>
-   <author>
-    <firstname>Alan</firstname>
-    <surname>Cox</surname>
-    <affiliation>
-     <address>
-      <email>alan@redhat.com</email>
-     </address>
-    </affiliation>
-   </author>
-  </authorgroup>
-
-  <copyright>
-   <year>2000</year>
-   <holder>Alan Cox</holder>
-  </copyright>
-
-  <legalnotice>
-   <para>
-     This documentation is free software; you can redistribute
-     it and/or modify it under the terms of the GNU General Public
-     License as published by the Free Software Foundation; either
-     version 2 of the License, or (at your option) any later
-     version.
-   </para>
-      
-   <para>
-     This program is distributed in the hope that it will be
-     useful, but WITHOUT ANY WARRANTY; without even the implied
-     warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-     See the GNU General Public License for more details.
-   </para>
-      
-   <para>
-     You should have received a copy of the GNU General Public
-     License along with this program; if not, write to the Free
-     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-     MA 02111-1307 USA
-   </para>
-      
-   <para>
-     For more details see the file COPYING in the source
-     distribution of Linux.
-   </para>
-  </legalnotice>
- </bookinfo>
-
-<toc></toc>
-
-  <chapter id="intro">
-      <title>Introduction</title>
-  <para>
-        Parts of this document first appeared in Linux Magazine under a
-        ninety day exclusivity.
-  </para>
-  <para>
-        Video4Linux is intended to provide a common programming interface
-        for the many TV and capture cards now on the market, as well as
-        parallel port and USB video cameras. Radio, teletext decoders and
-        vertical blanking data interfaces are also provided.
-  </para>
-  </chapter>
-  <chapter id="radio">
-        <title>Radio Devices</title>
-  <para>
-        There are a wide variety of radio interfaces available for PC's, and these
-        are generally very simple to program. The biggest problem with supporting
-        such devices is normally extracting documentation from the vendor.
-  </para>
-  <para>
-        The radio interface supports a simple set of control ioctls standardised
-        across all radio and tv interfaces. It does not support read or write, which
-        are used for video streams. The reason radio cards do not allow you to read
-        the audio stream into an application is that without exception they provide
-        a connection on to a soundcard. Soundcards can be used to read the radio
-        data just fine. 
-  </para>
-  <sect1 id="registerradio">
-  <title>Registering Radio Devices</title>
-  <para>
-        The Video4linux core provides an interface for registering devices. The
-        first step in writing our radio card driver is to register it.
-  </para>
-  <programlisting>
-
-
-static struct video_device my_radio
-{
-        "My radio",
-        VID_TYPE_TUNER,
-        radio_open.
-        radio_close,
-        NULL,                /* no read */
-        NULL,                 /* no write */
-        NULL,                /* no poll */
-        radio_ioctl,
-        NULL,                /* no special init function */
-        NULL                /* no private data */
-};
-
-
-  </programlisting>
-  <para>
-        This declares our video4linux device driver interface. The VID_TYPE_ value
-        defines what kind of an interface we are, and defines basic capabilities.
-  </para>
-  <para>
-        The only defined value relevant for a radio card is VID_TYPE_TUNER which
-        indicates that the device can be tuned. Clearly our radio is going to have some
-        way to change channel so it is tuneable.
-  </para>
-  <para>
-        We declare an open and close routine, but we do not need read or write,
-        which are used to read and write video data to or from the card itself. As
-        we have no read or write there is no poll function.
-  </para>
-  <para>
-        The private initialise function is run when the device is registered. In
-        this driver we've already done all the work needed. The final pointer is a
-        private data pointer that can be used by the device driver to attach and
-        retrieve private data structures. We set this field "priv" to NULL for
-        the moment.
-  </para>
-  <para>
-        Having the structure defined is all very well but we now need to register it
-        with the kernel. 
-  </para>
-  <programlisting>
-
-
-static int io = 0x320;
-
-int __init myradio_init(struct video_init *v)
-{
-        if(!request_region(io, MY_IO_SIZE, "myradio"))
-        {
-                printk(KERN_ERR 
-                    "myradio: port 0x%03X is in use.\n", io);
-                return -EBUSY;
-        }
-
-        if(video_device_register(&amp;my_radio, VFL_TYPE_RADIO)==-1) {
-                release_region(io, MY_IO_SIZE);
-                return -EINVAL;
-        }		
-        return 0;
-}
-
-  </programlisting>
-  <para>
-        The first stage of the initialisation, as is normally the case, is to check 
-        that the I/O space we are about to fiddle with doesn't belong to some other 
-        driver. If it is we leave well alone. If the user gives the address of the 
-        wrong device then we will spot this. These policies will generally avoid 
-        crashing the machine.
-  </para>
-  <para>
-        Now we ask the Video4Linux layer to register the device for us. We hand it
-        our carefully designed video_device structure and also tell it which group
-        of devices we want it registered with. In this case VFL_TYPE_RADIO.
-  </para>
-  <para>
-        The types available are
-  </para>
-   <table frame="all" id="Device_Types"><title>Device Types</title>
-   <tgroup cols="3" align="left">
-   <tbody>
-   <row>
-        <entry>VFL_TYPE_RADIO</entry><entry>/dev/radio{n}</entry><entry>
-
-        Radio devices are assigned in this block. As with all of these
-        selections the actual number assignment is done by the video layer
-        accordijng to what is free.</entry>
-	</row><row>
-        <entry>VFL_TYPE_GRABBER</entry><entry>/dev/video{n}</entry><entry>
-        Video capture devices and also -- counter-intuitively for the name --
-        hardware video playback devices such as MPEG2 cards.</entry>
-	</row><row>
-        <entry>VFL_TYPE_VBI</entry><entry>/dev/vbi{n}</entry><entry>
-        The VBI devices capture the hidden lines on a television picture
-        that carry further information like closed caption data, teletext
-        (primarily in Europe) and now Intercast and the ATVEC internet
-        television encodings.</entry>
-	</row><row>
-        <entry>VFL_TYPE_VTX</entry><entry>/dev/vtx[n}</entry><entry>
-        VTX is 'Videotext' also known as 'Teletext'. This is a system for
-        sending numbered, 40x25, mostly textual page images over the hidden
-        lines. Unlike the /dev/vbi interfaces, this is for 'smart' decoder 
-        chips. (The use of the word smart here has to be taken in context,
-        the smartest teletext chips are fairly dumb pieces of technology).
-	</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-  <para>
-        We are most definitely a radio.
-  </para>
-  <para>
-        Finally we allocate our I/O space so that nobody treads on us and return 0
-        to signify general happiness with the state of the universe.
-  </para>
-  </sect1>
-  <sect1 id="openradio">
-  <title>Opening And Closing The Radio</title>
-
-  <para>
-        The functions we declared in our video_device are mostly very simple.
-        Firstly we can drop in what is basically standard code for open and close. 
-  </para>
-  <programlisting>
-
-
-static int users = 0;
-
-static int radio_open(struct video_device *dev, int flags)
-{
-        if(users)
-                return -EBUSY;
-        users++;
-        return 0;
-}
-
-  </programlisting>
-  <para>
-        At open time we need to do nothing but check if someone else is also using
-        the radio card. If nobody is using it we make a note that we are using it,
-        then we ensure that nobody unloads our driver on us.
-  </para>
-  <programlisting>
-
-
-static int radio_close(struct video_device *dev)
-{
-        users--;
-}
-
-  </programlisting>
-  <para>
-        At close time we simply need to reduce the user count and allow the module
-        to become unloadable.
-  </para>
-  <para>
-        If you are sharp you will have noticed neither the open nor the close
-        routines attempt to reset or change the radio settings. This is intentional.
-        It allows an application to set up the radio and exit. It avoids a user
-        having to leave an application running all the time just to listen to the
-        radio. 
-  </para>
-  </sect1>
-  <sect1 id="ioctlradio">
-  <title>The Ioctl Interface</title>
-  <para>
-        This leaves the ioctl routine, without which the driver will not be
-        terribly useful to anyone.
-  </para>
-  <programlisting>
-
-
-static int radio_ioctl(struct video_device *dev, unsigned int cmd, void *arg)
-{
-        switch(cmd)
-        {
-                case VIDIOCGCAP:
-                {
-                        struct video_capability v;
-                        v.type = VID_TYPE_TUNER;
-                        v.channels = 1;
-                        v.audios = 1;
-                        v.maxwidth = 0;
-                        v.minwidth = 0;
-                        v.maxheight = 0;
-                        v.minheight = 0;
-                        strcpy(v.name, "My Radio");
-                        if(copy_to_user(arg, &amp;v, sizeof(v)))
-                                return -EFAULT;
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        VIDIOCGCAP is the first ioctl all video4linux devices must support. It
-        allows the applications to find out what sort of a card they have found and
-        to figure out what they want to do about it. The fields in the structure are
-  </para>
-   <table frame="all" id="video_capability_fields"><title>struct video_capability fields</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-        <entry>name</entry><entry>The device text name. This is intended for the user.</entry>
-	</row><row>
-        <entry>channels</entry><entry>The number of different channels you can tune on
-                        this card. It could even by zero for a card that has
-                        no tuning capability. For our simple FM radio it is 1. 
-                        An AM/FM radio would report 2.</entry>
-	</row><row>
-        <entry>audios</entry><entry>The number of audio inputs on this device. For our
-                        radio there is only one audio input.</entry>
-	</row><row>
-        <entry>minwidth,minheight</entry><entry>The smallest size the card is capable of capturing
-		        images in. We set these to zero. Radios do not
-                        capture pictures</entry>
-	</row><row>
-        <entry>maxwidth,maxheight</entry><entry>The largest image size the card is capable of
-                                      capturing. For our radio we report 0.
-				</entry>
-	</row><row>
-        <entry>type</entry><entry>This reports the capabilities of the device, and
-                        matches the field we filled in in the struct
-                        video_device when registering.</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-  <para>
-        Having filled in the fields, we use copy_to_user to copy the structure into
-        the users buffer. If the copy fails we return an EFAULT to the application
-        so that it knows it tried to feed us garbage.
-  </para>
-  <para>
-        The next pair of ioctl operations select which tuner is to be used and let
-        the application find the tuner properties. We have only a single FM band
-        tuner in our example device.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCGTUNER:
-                {
-                        struct video_tuner v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v))!=0)
-                                return -EFAULT;
-                        if(v.tuner)
-                                return -EINVAL;
-                        v.rangelow=(87*16000);
-                        v.rangehigh=(108*16000);
-                        v.flags = VIDEO_TUNER_LOW;
-                        v.mode = VIDEO_MODE_AUTO;
-                        v.signal = 0xFFFF;
-                        strcpy(v.name, "FM");
-                        if(copy_to_user(&amp;v, arg, sizeof(v))!=0)
-                                return -EFAULT;
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        The VIDIOCGTUNER ioctl allows applications to query a tuner. The application
-        sets the tuner field to the tuner number it wishes to query. The query does
-        not change the tuner that is being used, it merely enquires about the tuner
-        in question.
-  </para>
-  <para>
-        We have exactly one tuner so after copying the user buffer to our temporary
-        structure we complain if they asked for a tuner other than tuner 0. 
-  </para>
-  <para>
-        The video_tuner structure has the following fields
-  </para>
-   <table frame="all" id="video_tuner_fields"><title>struct video_tuner fields</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-        <entry>int tuner</entry><entry>The number of the tuner in question</entry>
-   </row><row>
-        <entry>char name[32]</entry><entry>A text description of this tuner. "FM" will do fine.
-                        This is intended for the application.</entry>
-   </row><row>
-        <entry>u32 flags</entry>
-        <entry>Tuner capability flags</entry>
-   </row>
-   <row>
-        <entry>u16 mode</entry><entry>The current reception mode</entry>
-
-   </row><row>
-        <entry>u16 signal</entry><entry>The signal strength scaled between 0 and 65535. If
-                        a device cannot tell the signal strength it should
-                        report 65535. Many simple cards contain only a 
-                        signal/no signal bit. Such cards will report either
-                        0 or 65535.</entry>
-
-   </row><row>
-        <entry>u32 rangelow, rangehigh</entry><entry>
-                        The range of frequencies supported by the radio
-                        or TV. It is scaled according to the VIDEO_TUNER_LOW
-                        flag.</entry>
-
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-
-   <table frame="all" id="video_tuner_flags"><title>struct video_tuner flags</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-	<entry>VIDEO_TUNER_PAL</entry><entry>A PAL TV tuner</entry>
-	</row><row>
-        <entry>VIDEO_TUNER_NTSC</entry><entry>An NTSC (US) TV tuner</entry>
-	</row><row>
-        <entry>VIDEO_TUNER_SECAM</entry><entry>A SECAM (French) TV tuner</entry>
-	</row><row>
-        <entry>VIDEO_TUNER_LOW</entry><entry>
-             The tuner frequency is scaled in 1/16th of a KHz
-             steps. If not it is in 1/16th of a MHz steps
-	</entry>
-	</row><row>
-        <entry>VIDEO_TUNER_NORM</entry><entry>The tuner can set its format</entry>
-	</row><row>
-        <entry>VIDEO_TUNER_STEREO_ON</entry><entry>The tuner is currently receiving a stereo signal</entry>
-        </row>
-    </tbody>
-    </tgroup>
-    </table>
-
-   <table frame="all" id="video_tuner_modes"><title>struct video_tuner modes</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-                <entry>VIDEO_MODE_PAL</entry><entry>PAL Format</entry>
-   </row><row>
-                <entry>VIDEO_MODE_NTSC</entry><entry>NTSC Format (USA)</entry>
-   </row><row>
-                <entry>VIDEO_MODE_SECAM</entry><entry>French Format</entry>
-   </row><row>
-                <entry>VIDEO_MODE_AUTO</entry><entry>A device that does not need to do
-                                        TV format switching</entry>
-   </row>
-    </tbody>
-    </tgroup>
-    </table>
-  <para>
-        The settings for the radio card are thus fairly simple. We report that we
-        are a tuner called "FM" for FM radio. In order to get the best tuning
-        resolution we report VIDEO_TUNER_LOW and select tuning to 1/16th of KHz. Its
-        unlikely our card can do that resolution but it is a fair bet the card can
-        do better than 1/16th of a MHz. VIDEO_TUNER_LOW is appropriate to almost all
-        radio usage.
-  </para>
-  <para>
-        We report that the tuner automatically handles deciding what format it is
-        receiving - true enough as it only handles FM radio. Our example card is
-        also incapable of detecting stereo or signal strengths so it reports a
-        strength of 0xFFFF (maximum) and no stereo detected.
-  </para>
-  <para>
-        To finish off we set the range that can be tuned to be 87-108Mhz, the normal
-        FM broadcast radio range. It is important to find out what the card is
-        actually capable of tuning. It is easy enough to simply use the FM broadcast
-        range. Unfortunately if you do this you will discover the FM broadcast
-        ranges in the USA, Europe and Japan are all subtly different and some users
-        cannot receive all the stations they wish.
-  </para>
-  <para>
-        The application also needs to be able to set the tuner it wishes to use. In
-        our case, with a single tuner this is rather simple to arrange.
-  </para>
-  <programlisting>
-
-                case VIDIOCSTUNER:
-                {
-                        struct video_tuner v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.tuner != 0)
-                                return -EINVAL;
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        We copy the user supplied structure into kernel memory so we can examine it. 
-        If the user has selected a tuner other than zero we reject the request. If 
-        they wanted tuner 0 then, surprisingly enough, that is the current tuner already.
-  </para>
-  <para>
-        The next two ioctls we need to provide are to get and set the frequency of
-        the radio. These both use an unsigned long argument which is the frequency.
-        The scale of the frequency depends on the VIDEO_TUNER_LOW flag as I
-        mentioned earlier on. Since we have VIDEO_TUNER_LOW set this will be in
-        1/16ths of a KHz.
-  </para>
-  <programlisting>
-
-static unsigned long current_freq;
-
-
-
-                case VIDIOCGFREQ:
-                        if(copy_to_user(arg, &amp;current_freq, 
-                                sizeof(unsigned long))
-                                return -EFAULT;
-                        return 0;
-
-  </programlisting>
-  <para>
-        Querying the frequency in our case is relatively simple. Our radio card is
-        too dumb to let us query the signal strength so we remember our setting if 
-        we know it. All we have to do is copy it to the user.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCSFREQ:
-                {
-                        u32 freq;
-                        if(copy_from_user(arg, &amp;freq, 
-                                sizeof(unsigned long))!=0)
-                                return -EFAULT;
-                        if(hardware_set_freq(freq)&lt;0)
-                                return -EINVAL;
-                        current_freq = freq;
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        Setting the frequency is a little more complex. We begin by copying the
-        desired frequency into kernel space. Next we call a hardware specific routine
-        to set the radio up. This might be as simple as some scaling and a few
-        writes to an I/O port. For most radio cards it turns out a good deal more
-        complicated and may involve programming things like a phase locked loop on
-        the card. This is what documentation is for. 
-  </para>
-  <para>
-        The final set of operations we need to provide for our radio are the 
-        volume controls. Not all radio cards can even do volume control. After all
-        there is a perfectly good volume control on the sound card. We will assume
-        our radio card has a simple 4 step volume control.
-  </para>
-  <para>
-        There are two ioctls with audio we need to support
-  </para>
-  <programlisting>
-
-static int current_volume=0;
-
-                case VIDIOCGAUDIO:
-                {
-                        struct video_audio v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.audio != 0)
-                                return -EINVAL;
-                        v.volume = 16384*current_volume;
-                        v.step = 16384;
-                        strcpy(v.name, "Radio");
-                        v.mode = VIDEO_SOUND_MONO;
-                        v.balance = 0;
-                        v.base = 0;
-                        v.treble = 0;
-                        
-                        if(copy_to_user(arg. &amp;v, sizeof(v)))
-                                return -EFAULT;
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        Much like the tuner we start by copying the user structure into kernel
-        space. Again we check if the user has asked for a valid audio input. We have
-        only input 0 and we punt if they ask for another input.
-  </para>
-  <para>
-        Then we fill in the video_audio structure. This has the following format
-  </para>
-   <table frame="all" id="video_audio_fields"><title>struct video_audio fields</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-   <entry>audio</entry><entry>The input the user wishes to query</entry>
-   </row><row>
-   <entry>volume</entry><entry>The volume setting on a scale of 0-65535</entry>
-   </row><row>
-   <entry>base</entry><entry>The base level on a scale of 0-65535</entry>
-   </row><row>
-   <entry>treble</entry><entry>The treble level on a scale of 0-65535</entry>
-   </row><row>
-   <entry>flags</entry><entry>The features this audio device supports
-   </entry>
-   </row><row>
-   <entry>name</entry><entry>A text name to display to the user. We picked
-                        "Radio" as it explains things quite nicely.</entry>
-   </row><row>
-   <entry>mode</entry><entry>The current reception mode for the audio
-
-                We report MONO because our card is too stupid to know if it is in
-                mono or stereo. 
-   </entry>
-   </row><row>
-   <entry>balance</entry><entry>The stereo balance on a scale of 0-65535, 32768 is
-                        middle.</entry>
-   </row><row>
-   <entry>step</entry><entry>The step by which the volume control jumps. This is
-                        used to help make it easy for applications to set 
-                        slider behaviour.</entry>
-   </row>
-   </tbody>
-   </tgroup>
-   </table>
-
-   <table frame="all" id="video_audio_flags"><title>struct video_audio flags</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-                <entry>VIDEO_AUDIO_MUTE</entry><entry>The audio is currently muted. We
-                                        could fake this in our driver but we
-                                        choose not to bother.</entry>
-   </row><row>
-                <entry>VIDEO_AUDIO_MUTABLE</entry><entry>The input has a mute option</entry>
-   </row><row>
-                <entry>VIDEO_AUDIO_TREBLE</entry><entry>The  input has a treble control</entry>
-   </row><row>
-                <entry>VIDEO_AUDIO_BASS</entry><entry>The input has a base control</entry>
-   </row>
-   </tbody>
-   </tgroup>
-   </table>
-
-   <table frame="all" id="video_audio_modes"><title>struct video_audio modes</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-                <entry>VIDEO_SOUND_MONO</entry><entry>Mono sound</entry>
-   </row><row>
-                <entry>VIDEO_SOUND_STEREO</entry><entry>Stereo sound</entry>
-   </row><row>
-                <entry>VIDEO_SOUND_LANG1</entry><entry>Alternative language 1 (TV specific)</entry>
-   </row><row>
-                <entry>VIDEO_SOUND_LANG2</entry><entry>Alternative language 2 (TV specific)</entry>
-   </row>
-   </tbody>
-   </tgroup>
-   </table>
-  <para>
-        Having filled in the structure we copy it back to user space.
-  </para>
-  <para>
-        The VIDIOCSAUDIO ioctl allows the user to set the audio parameters in the
-        video_audio structure. The driver does its best to honour the request.
-  </para>
-  <programlisting>
-
-                case VIDIOCSAUDIO:
-                {
-                        struct video_audio v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.audio)
-                                return -EINVAL;
-                        current_volume = v/16384;
-                        hardware_set_volume(current_volume);
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        In our case there is very little that the user can set. The volume is
-        basically the limit. Note that we could pretend to have a mute feature
-        by rewriting this to 
-  </para>
-  <programlisting>
-
-                case VIDIOCSAUDIO:
-                {
-                        struct video_audio v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.audio)
-                                return -EINVAL;
-                        current_volume = v/16384;
-                        if(v.flags&amp;VIDEO_AUDIO_MUTE)
-                                hardware_set_volume(0);
-                        else
-                                hardware_set_volume(current_volume);
-                        current_muted = v.flags &amp; 
-                                              VIDEO_AUDIO_MUTE;
-                        return 0;
-                }
-
-  </programlisting>
-  <para>
-        This with the corresponding changes to the VIDIOCGAUDIO code to report the
-        state of the mute flag we save and to report the card has a mute function,
-        will allow applications to use a mute facility with this card. It is
-        questionable whether this is a good idea however. User applications can already
-        fake this themselves and kernel space is precious.
-  </para>
-  <para>
-        We now have a working radio ioctl handler. So we just wrap up the function
-  </para>
-  <programlisting>
-
-
-        }
-        return -ENOIOCTLCMD;
-}
-
-  </programlisting>
-  <para>
-        and pass the Video4Linux layer back an error so that it knows we did not
-        understand the request we got passed.
-  </para>
-  </sect1>
-  <sect1 id="modradio">
-  <title>Module Wrapper</title>
-  <para>
-        Finally we add in the usual module wrapping and the driver is done.
-  </para>
-  <programlisting>
-
-#ifndef MODULE
-
-static int io = 0x300;
-
-#else
-
-static int io = -1;
-
-#endif
-
-MODULE_AUTHOR("Alan Cox");
-MODULE_DESCRIPTION("A driver for an imaginary radio card.");
-module_param(io, int, 0444);
-MODULE_PARM_DESC(io, "I/O address of the card.");
-
-static int __init init(void)
-{
-        if(io==-1)
-        {
-                printk(KERN_ERR 
-         "You must set an I/O address with io=0x???\n");
-                return -EINVAL;
-        }
-        return myradio_init(NULL);
-}
-
-static void __exit cleanup(void)
-{
-        video_unregister_device(&amp;my_radio);
-        release_region(io, MY_IO_SIZE);
-}
-
-module_init(init);
-module_exit(cleanup);
-
-  </programlisting>
-  <para>
-        In this example we set the IO base by default if the driver is compiled into
-        the kernel: you can still set it using "my_radio.irq" if this file is called <filename>my_radio.c</filename>. For the module we require the
-        user sets the parameter. We set io to a nonsense port (-1) so that we can
-        tell if the user supplied an io parameter or not.
-  </para>
-  <para>
-        We use MODULE_ defines to give an author for the card driver and a
-        description. We also use them to declare that io is an integer and it is the
-        address of the card, and can be read by anyone from sysfs.
-  </para>
-  <para>
-        The clean-up routine unregisters the video_device we registered, and frees
-        up the I/O space. Note that the unregister takes the actual video_device
-        structure as its argument. Unlike the file operations structure which can be
-        shared by all instances of a device a video_device structure as an actual
-        instance of the device. If you are registering multiple radio devices you
-        need to fill in one structure per device (most likely by setting up a
-        template and copying it to each of the actual device structures).
-  </para>
-  </sect1>
-  </chapter>
-  <chapter id="Video_Capture_Devices">
-        <title>Video Capture Devices</title>
-  <sect1 id="introvid">
-  <title>Video Capture Device Types</title>
-  <para>
-        The video capture devices share the same interfaces as radio devices. In
-        order to explain the video capture interface I will use the example of a
-        camera that has no tuners or audio input. This keeps the example relatively
-        clean. To get both combine the two driver examples.
-  </para>
-  <para>
-        Video capture devices divide into four categories. A little technology
-        backgrounder. Full motion video even at television resolution (which is
-        actually fairly low) is pretty resource-intensive. You are continually
-        passing megabytes of data every second from the capture card to the display. 
-        several alternative approaches have emerged because copying this through the 
-        processor and the user program is a particularly bad idea .
-  </para>
-  <para>
-        The first is to add the television image onto the video output directly.
-        This is also how some 3D cards work. These basic cards can generally drop the
-        video into any chosen rectangle of the display. Cards like this, which
-        include most mpeg1 cards that used the feature connector,  aren't very
-        friendly in a windowing environment. They don't understand windows or
-        clipping. The video window is always on the top of the display.
-  </para>
-  <para>
-        Chroma keying is a technique used by cards to get around this. It is an old
-        television mixing trick where you mark all the areas you wish to replace
-        with a single clear colour that isn't used in the image - TV people use an
-        incredibly bright blue while computing people often use a particularly
-        virulent purple. Bright blue occurs on the desktop. Anyone with virulent
-        purple windows has another problem besides their TV overlay.
-  </para>
-  <para>
-        The third approach is to copy the data from the capture card to the video
-        card, but to do it directly across the PCI bus. This relieves the processor
-        from doing the work but does require some smartness on the part of the video
-        capture chip, as well as a suitable video card. Programming this kind of
-        card and more so debugging it can be extremely tricky. There are some quite
-        complicated interactions with the display and you may also have to cope with
-        various chipset bugs that show up when PCI cards start talking to each
-        other. 
-  </para>
-  <para>
-        To keep our example fairly simple we will assume a card that supports
-        overlaying a flat rectangular image onto the frame buffer output, and which
-        can also capture stuff into processor memory.
-  </para>
-  </sect1>
-  <sect1 id="regvid">
-  <title>Registering Video Capture Devices</title>
-  <para>
-        This time we need to add more functions for our camera device.
-  </para>
-  <programlisting>
-static struct video_device my_camera
-{
-        "My Camera",
-        VID_TYPE_OVERLAY|VID_TYPE_SCALES|\
-        VID_TYPE_CAPTURE|VID_TYPE_CHROMAKEY,
-        camera_open.
-        camera_close,
-        camera_read,      /* no read */
-        NULL,             /* no write */
-        camera_poll,      /* no poll */
-        camera_ioctl,
-        NULL,             /* no special init function */
-        NULL              /* no private data */
-};
-  </programlisting>
-  <para>
-        We need a read() function which is used for capturing data from
-        the card, and we need a poll function so that a driver can wait for the next
-        frame to be captured.
-  </para>
-  <para>
-        We use the extra video capability flags that did not apply to the
-        radio interface. The video related flags are
-  </para>
-   <table frame="all" id="Capture_Capabilities"><title>Capture Capabilities</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-<entry>VID_TYPE_CAPTURE</entry><entry>We support image capture</entry>
-</row><row>
-<entry>VID_TYPE_TELETEXT</entry><entry>A teletext capture device (vbi{n])</entry>
-</row><row>
-<entry>VID_TYPE_OVERLAY</entry><entry>The image can be directly overlaid onto the
-                                frame buffer</entry>
-</row><row>
-<entry>VID_TYPE_CHROMAKEY</entry><entry>Chromakey can be used to select which parts
-                                of the image to display</entry>
-</row><row>
-<entry>VID_TYPE_CLIPPING</entry><entry>It is possible to give the board a list of
-                                rectangles to draw around. </entry>
-</row><row>
-<entry>VID_TYPE_FRAMERAM</entry><entry>The video capture goes into the video memory
-                                and actually changes it. Applications need
-                                to know this so they can clean up after the
-                                card</entry>
-</row><row>
-<entry>VID_TYPE_SCALES</entry><entry>The image can be scaled to various sizes,
-                                rather than being a single fixed size.</entry>
-</row><row>
-<entry>VID_TYPE_MONOCHROME</entry><entry>The capture will be monochrome. This isn't a
-                                complete answer to the question since a mono
-                                camera on a colour capture card will still
-                                produce mono output.</entry>
-</row><row>
-<entry>VID_TYPE_SUBCAPTURE</entry><entry>The card allows only part of its field of
-                                view to be captured. This enables
-                                applications to avoid copying all of a large
-                                image into memory when only some section is
-                                relevant.</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-  <para>
-        We set VID_TYPE_CAPTURE so that we are seen as a capture card,
-        VID_TYPE_CHROMAKEY so the application knows it is time to draw in virulent
-        purple, and VID_TYPE_SCALES because we can be resized.
-  </para>
-  <para>
-        Our setup is fairly similar. This time we also want an interrupt line
-        for the 'frame captured' signal. Not all cards have this so some of them
-        cannot handle poll().
-  </para>
-  <programlisting>
-
-
-static int io = 0x320;
-static int irq = 11;
-
-int __init mycamera_init(struct video_init *v)
-{
-        if(!request_region(io, MY_IO_SIZE, "mycamera"))
-        {
-                printk(KERN_ERR 
-                      "mycamera: port 0x%03X is in use.\n", io);
-                return -EBUSY;
-        }
-
-        if(video_device_register(&amp;my_camera, 
-            VFL_TYPE_GRABBER)==-1) {
-                release_region(io, MY_IO_SIZE);
-                return -EINVAL;
-        }
-        return 0;
-}
-
-  </programlisting>
-  <para>
-        This is little changed from the needs of the radio card. We specify
-        VFL_TYPE_GRABBER this time as we want to be allocated a /dev/video name.
-  </para>
-  </sect1>
-  <sect1 id="opvid">
-  <title>Opening And Closing The Capture Device</title>
-  <programlisting>
-
-
-static int users = 0;
-
-static int camera_open(struct video_device *dev, int flags)
-{
-        if(users)
-                return -EBUSY;
-        if(request_irq(irq, camera_irq, 0, "camera", dev)&lt;0)
-                return -EBUSY;
-        users++;
-        return 0;
-}
-
-
-static int camera_close(struct video_device *dev)
-{
-        users--;
-        free_irq(irq, dev);
-}
-  </programlisting>
-  <para>
-        The open and close routines are also quite similar. The only real change is
-        that we now request an interrupt for the camera device interrupt line. If we
-        cannot get the interrupt we report EBUSY to the application and give up.
-  </para>
-  </sect1>
-  <sect1 id="irqvid">
-  <title>Interrupt Handling</title>
-  <para>
-        Our example handler is for an ISA bus device. If it was PCI you would be
-        able to share the interrupt and would have set IRQF_SHARED to indicate a
-        shared IRQ. We pass the device pointer as the interrupt routine argument. We
-        don't need to since we only support one card but doing this will make it
-        easier to upgrade the driver for multiple devices in the future.
-  </para>
-  <para>
-        Our interrupt routine needs to do little if we assume the card can simply
-        queue one frame to be read after it captures it. 
-  </para>
-  <programlisting>
-
-
-static struct wait_queue *capture_wait;
-static int capture_ready = 0;
-
-static void camera_irq(int irq, void *dev_id, 
-                          struct pt_regs *regs)
-{
-        capture_ready=1;
-        wake_up_interruptible(&amp;capture_wait);
-}
-  </programlisting>
-  <para>
-        The interrupt handler is nice and simple for this card as we are assuming
-        the card is buffering the frame for us. This means we have little to do but
-        wake up        anybody interested. We also set a capture_ready flag, as we may
-        capture a frame before an application needs it. In this case we need to know
-        that a frame is ready. If we had to collect the frame on the interrupt life
-        would be more complex.
-  </para>
-  <para>
-        The two new routines we need to supply are camera_read which returns a
-        frame, and camera_poll which waits for a frame to become ready.
-  </para>
-  <programlisting>
-
-
-static int camera_poll(struct video_device *dev, 
-	struct file *file, struct poll_table *wait)
-{
-        poll_wait(file, &amp;capture_wait, wait);
-        if(capture_read)
-                return POLLIN|POLLRDNORM;
-        return 0;
-}
-
-  </programlisting>
-  <para>
-        Our wait queue for polling is the capture_wait queue. This will cause the
-        task to be woken up by our camera_irq routine. We check capture_read to see
-        if there is an image present and if so report that it is readable.
-  </para>
-  </sect1>
-  <sect1 id="rdvid">
-  <title>Reading The Video Image</title>
-  <programlisting>
-
-
-static long camera_read(struct video_device *dev, char *buf,
-                                unsigned long count)
-{
-        struct wait_queue wait = { current, NULL };
-        u8 *ptr;
-        int len;
-        int i;
-
-        add_wait_queue(&amp;capture_wait, &amp;wait);
-
-        while(!capture_ready)
-        {
-                if(file->flags&amp;O_NDELAY)
-                {
-                        remove_wait_queue(&amp;capture_wait, &amp;wait);
-                        current->state = TASK_RUNNING;
-                        return -EWOULDBLOCK;
-                }
-                if(signal_pending(current))
-                {
-                        remove_wait_queue(&amp;capture_wait, &amp;wait);
-                        current->state = TASK_RUNNING;
-                        return -ERESTARTSYS;
-                }
-                schedule();
-                current->state = TASK_INTERRUPTIBLE;
-        }
-        remove_wait_queue(&amp;capture_wait, &amp;wait);
-        current->state = TASK_RUNNING;
-
-  </programlisting>
-  <para>
-        The first thing we have to do is to ensure that the application waits until
-        the next frame is ready. The code here is almost identical to the mouse code
-        we used earlier in this chapter. It is one of the common building blocks of
-        Linux device driver code and probably one which you will find occurs in any
-        drivers you write.
-  </para>
-  <para>
-        We wait for a frame to be ready, or for a signal to interrupt our waiting. If a
-        signal occurs we need to return from the system call so that the signal can
-        be sent to the application itself. We also check to see if the user actually
-        wanted to avoid waiting - ie  if they are using non-blocking I/O and have other things 
-        to get on with.
-  </para>
-  <para>
-        Next we copy the data from the card to the user application. This is rarely
-        as easy as our example makes out. We will add capture_w, and capture_h here
-        to hold the width and height of the captured image. We assume the card only
-        supports 24bit RGB for now.
-  </para>
-  <programlisting>
-
-
-
-        capture_ready = 0;
-
-        ptr=(u8 *)buf;
-        len = capture_w * 3 * capture_h; /* 24bit RGB */
-
-        if(len>count)
-                len=count;  /* Doesn't all fit */
-
-        for(i=0; i&lt;len; i++)
-        {
-                put_user(inb(io+IMAGE_DATA), ptr);
-                ptr++;
-        }
-
-        hardware_restart_capture();
-                
-        return i;
-}
-
-  </programlisting>
-  <para>
-        For a real hardware device you would try to avoid the loop with put_user().
-        Each call to put_user() has a time overhead checking whether the accesses to user
-        space are allowed. It would be better to read a line into a temporary buffer
-        then copy this to user space in one go.
-  </para>
-  <para>
-        Having captured the image and put it into user space we can kick the card to
-        get the next frame acquired.
-  </para>
-  </sect1>
-  <sect1 id="iocvid">
-  <title>Video Ioctl Handling</title>
-  <para>
-        As with the radio driver the major control interface is via the ioctl()
-        function. Video capture devices support the same tuner calls as a radio
-        device and also support additional calls to control how the video functions
-        are handled. In this simple example the card has no tuners to avoid making
-        the code complex. 
-  </para>
-  <programlisting>
-
-
-
-static int camera_ioctl(struct video_device *dev, unsigned int cmd, void *arg)
-{
-        switch(cmd)
-        {
-                case VIDIOCGCAP:
-                {
-                        struct video_capability v;
-                        v.type = VID_TYPE_CAPTURE|\
-                                 VID_TYPE_CHROMAKEY|\
-                                 VID_TYPE_SCALES|\
-                                 VID_TYPE_OVERLAY;
-                        v.channels = 1;
-                        v.audios = 0;
-                        v.maxwidth = 640;
-                        v.minwidth = 16;
-                        v.maxheight = 480;
-                        v.minheight = 16;
-                        strcpy(v.name, "My Camera");
-                        if(copy_to_user(arg, &amp;v, sizeof(v)))
-                                return -EFAULT;
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        The first ioctl we must support and which all video capture and radio
-        devices are required to support is VIDIOCGCAP. This behaves exactly the same
-        as with a radio device. This time, however, we report the extra capabilities
-        we outlined earlier on when defining our video_dev structure.
-  </para>
-  <para>
-        We now set the video flags saying that we support overlay, capture,
-        scaling and chromakey. We also report size limits - our smallest image is
-        16x16 pixels, our largest is 640x480. 
-  </para>
-  <para>
-        To keep things simple we report no audio and no tuning capabilities at all.
-  </para>
-  <programlisting>        
-
-                case VIDIOCGCHAN:
-                {
-                        struct video_channel v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.channel != 0)
-                                return -EINVAL;
-                        v.flags = 0;
-                        v.tuners = 0;
-                        v.type = VIDEO_TYPE_CAMERA;
-                        v.norm = VIDEO_MODE_AUTO;
-                        strcpy(v.name, "Camera Input");break;
-                        if(copy_to_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        This follows what is very much the standard way an ioctl handler looks
-        in Linux. We copy the data into a kernel space variable and we check that the
-        request is valid (in this case that the input is 0). Finally we copy the
-        camera info back to the user.
-  </para>
-  <para>
-        The VIDIOCGCHAN ioctl allows a user to ask about video channels (that is
-        inputs to the video card). Our example card has a single camera input. The
-        fields in the structure are
-  </para>
-   <table frame="all" id="video_channel_fields"><title>struct video_channel fields</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-
-   <entry>channel</entry><entry>The channel number we are selecting</entry>
-   </row><row>
-   <entry>name</entry><entry>The name for this channel. This is intended
-                   to describe the port to the user.
-                   Appropriate names are therefore things like
-                   "Camera" "SCART input"</entry>
-   </row><row>
-   <entry>flags</entry><entry>Channel properties</entry>
-   </row><row>
-   <entry>type</entry><entry>Input type</entry>
-   </row><row>
-   <entry>norm</entry><entry>The current television encoding being used
-                   if relevant for this channel.
-    </entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-    <table frame="all" id="video_channel_flags"><title>struct video_channel flags</title>
-    <tgroup cols="2" align="left">
-    <tbody>
-    <row>
-        <entry>VIDEO_VC_TUNER</entry><entry>Channel has a tuner.</entry>
-   </row><row>
-        <entry>VIDEO_VC_AUDIO</entry><entry>Channel has audio.</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-    <table frame="all" id="video_channel_types"><title>struct video_channel types</title>
-    <tgroup cols="2" align="left">
-    <tbody>
-    <row>
-        <entry>VIDEO_TYPE_TV</entry><entry>Television input.</entry>
-   </row><row>
-        <entry>VIDEO_TYPE_CAMERA</entry><entry>Fixed camera input.</entry>
-   </row><row>
-	<entry>0</entry><entry>Type is unknown.</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-    <table frame="all" id="video_channel_norms"><title>struct video_channel norms</title>
-    <tgroup cols="2" align="left">
-    <tbody>
-    <row>
-        <entry>VIDEO_MODE_PAL</entry><entry>PAL encoded Television</entry>
-   </row><row>
-        <entry>VIDEO_MODE_NTSC</entry><entry>NTSC (US) encoded Television</entry>
-   </row><row>
-        <entry>VIDEO_MODE_SECAM</entry><entry>SECAM (French) Television </entry>
-   </row><row>
-        <entry>VIDEO_MODE_AUTO</entry><entry>Automatic switching, or format does not
-                                matter</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-    <para>
-        The corresponding VIDIOCSCHAN ioctl allows a user to change channel and to
-        request the norm is changed - for example to switch between a PAL or an NTSC
-        format camera.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCSCHAN:
-                {
-                        struct video_channel v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.channel != 0)
-                                return -EINVAL;
-                        if(v.norm != VIDEO_MODE_AUTO)
-                                return -EINVAL;
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        The implementation of this call in our driver is remarkably easy. Because we
-        are assuming fixed format hardware we need only check that the user has not
-        tried to change anything. 
-  </para>
-  <para>
-        The user also needs to be able to configure and adjust the picture they are
-        seeing. This is much like adjusting a television set. A user application
-        also needs to know the palette being used so that it knows how to display
-        the image that has been captured. The VIDIOCGPICT and VIDIOCSPICT ioctl
-        calls provide this information.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCGPICT
-                {
-                        struct video_picture v;
-                        v.brightness = hardware_brightness();
-                        v.hue = hardware_hue();
-                        v.colour = hardware_saturation();
-                        v.contrast = hardware_brightness();
-                        /* Not settable */
-                        v.whiteness = 32768;
-                        v.depth = 24;           /* 24bit */
-                        v.palette = VIDEO_PALETTE_RGB24;
-                        if(copy_to_user(&amp;v, arg, 
-                             sizeof(v)))
-                                return -EFAULT;
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        The brightness, hue, color, and contrast provide the picture controls that
-        are akin to a conventional television. Whiteness provides additional
-        control for greyscale images. All of these values are scaled between 0-65535
-        and have 32768 as the mid point setting. The scaling means that applications
-        do not have to worry about the capability range of the hardware but can let
-        it make a best effort attempt.
-  </para>
-  <para>
-        Our depth is 24, as this is in bits. We will be returning RGB24 format. This
-        has one byte of red, then one of green, then one of blue. This then repeats
-        for every other pixel in the image. The other common formats the interface 
-        defines are
-  </para>
-   <table frame="all" id="Framebuffer_Encodings"><title>Framebuffer Encodings</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-   <entry>GREY</entry><entry>Linear greyscale. This is for simple cameras and the
-                        like</entry>
-   </row><row>
-   <entry>RGB565</entry><entry>The top 5 bits hold 32 red levels, the next six bits
-                        hold green and the low 5 bits hold blue. </entry>
-   </row><row>
-   <entry>RGB555</entry><entry>The top bit is clear. The red green and blue levels
-                        each occupy five bits.</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-  <para>
-        Additional modes are support for YUV capture formats. These are common for
-        TV and video conferencing applications.
-  </para>
-  <para>
-        The VIDIOCSPICT ioctl allows a user to set some of the picture parameters.
-        Exactly which ones are supported depends heavily on the card itself. It is
-        possible to support many modes and effects in software. In general doing
-        this in the kernel is a bad idea. Video capture is a performance-sensitive
-        application and the programs can often do better if they aren't being
-        'helped' by an overkeen driver writer. Thus for our device we will report
-        RGB24 only and refuse to allow a change.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCSPICT:
-                {
-                        struct video_picture v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.depth!=24 || 
-                           v.palette != VIDEO_PALETTE_RGB24)
-                                return -EINVAL;
-                        set_hardware_brightness(v.brightness);
-                        set_hardware_hue(v.hue);
-                        set_hardware_saturation(v.colour);
-                        set_hardware_brightness(v.contrast);
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        We check the user has not tried to change the palette or the depth. We do
-        not want to carry out some of the changes and then return an error. This may
-        confuse the application which will be assuming no change occurred.
-  </para>
-  <para>
-        In much the same way as you need to be able to set the picture controls to
-        get the right capture images, many cards need to know what they are
-        displaying onto when generating overlay output. In some cases getting this
-        wrong even makes a nasty mess or may crash the computer. For that reason
-        the VIDIOCSBUF ioctl used to set up the frame buffer information may well
-        only be usable by root.
-  </para>
-  <para>
-        We will assume our card is one of the old ISA devices with feature connector
-        and only supports a couple of standard video modes. Very common for older
-        cards although the PCI devices are way smarter than this.
-  </para>
-  <programlisting>
-
-
-static struct video_buffer capture_fb;
-
-                case VIDIOCGFBUF:
-                {
-                        if(copy_to_user(arg, &amp;capture_fb, 
-                             sizeof(capture_fb)))
-                                return -EFAULT;
-                        return 0;
-                        
-                }
-
-
-  </programlisting>
-  <para>
-        We keep the frame buffer information in the format the ioctl uses. This
-        makes it nice and easy to work with in the ioctl calls.
-  </para>
-  <programlisting>
-
-                case VIDIOCSFBUF:
-                {
-                        struct video_buffer v;
-
-                        if(!capable(CAP_SYS_ADMIN))
-                                return -EPERM;
-
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.width!=320 &amp;&amp; v.width!=640)
-                                return -EINVAL;
-                        if(v.height!=200 &amp;&amp; v.height!=240 
-                                &amp;&amp; v.height!=400
-                                &amp;&amp; v.height !=480)
-                                return -EINVAL;
-                        memcpy(&amp;capture_fb, &amp;v, sizeof(v));
-                        hardware_set_fb(&amp;v);
-                        return 0;
-                }
-
-
-
-  </programlisting>
-  <para>
-        The capable() function checks a user has the required capability. The Linux
-        operating system has a set of about 30 capabilities indicating privileged
-        access to services. The default set up gives the superuser (uid 0) all of
-        them and nobody else has any.
-  </para>
-  <para>
-        We check that the user has the SYS_ADMIN capability, that is they are
-        allowed to operate as the machine administrator. We don't want anyone but
-        the administrator making a mess of the display.
-  </para>
-  <para>
-        Next we check for standard PC video modes (320 or 640 wide with either
-        EGA or VGA depths). If the mode is not a standard video mode we reject it as
-        not supported by our card. If the mode is acceptable we save it so that
-        VIDIOCFBUF will give the right answer next time it is called.  The
-        hardware_set_fb() function is some undescribed card specific function to
-        program the card for the desired mode.
-  </para>
-  <para>
-        Before the driver can display an overlay window it needs to know where the
-        window should be placed, and also how large it should be. If the card
-        supports clipping it needs to know which rectangles to omit from the
-        display. The video_window structure is used to describe the way the image 
-        should be displayed. 
-   </para>
-   <table frame="all" id="video_window_fields"><title>struct video_window fields</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-        <entry>width</entry><entry>The width in pixels of the desired image. The card
-                        may use a smaller size if this size is not available</entry>
-	</row><row>
-        <entry>height</entry><entry>The height of the image. The card may use a smaller
-                        size if this size is not available.</entry>
-	</row><row>
-        <entry>x</entry><entry>   The X position of the top left of the window. This
-                        is in pixels relative to the left hand edge of the
-                        picture. Not all cards can display images aligned on
-                        any pixel boundary. If the position is unsuitable
-                        the card adjusts the image right and reduces the
-                        width.</entry>
-	</row><row>
-        <entry>y</entry><entry>   The Y position of the top left of the window. This
-                        is counted in pixels relative to the top edge of the
-                        picture. As with the width if the card cannot
-                        display  starting on this line it will adjust the
-                        values.</entry>
-	</row><row>
-        <entry>chromakey</entry><entry>The colour (expressed in RGB32 format) for the
-                        chromakey colour if chroma keying is being used. </entry>
-	</row><row>
-        <entry>clips</entry><entry>An array of rectangles that must not be drawn
-			over.</entry>
-	</row><row>
-        <entry>clipcount</entry><entry>The number of clips in this array.</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-    <para>
-        Each clip is a struct video_clip which has the following fields
-   </para>
-   <table frame="all" id="video_clip_fields"><title>video_clip fields</title>
-   <tgroup cols="2" align="left">
-   <tbody>
-   <row>
-        <entry>x, y</entry><entry>Co-ordinates relative to the display</entry>
-	</row><row>
-        <entry>width, height</entry><entry>Width and height in pixels</entry>
-	</row><row>
-        <entry>next</entry><entry>A spare field for the application to use</entry>
-    </row>
-    </tbody>
-    </tgroup>
-    </table>
-    <para>
-        The driver is required to ensure it always draws in the area requested or a        smaller area, and that it never draws in any of the areas that are clipped.
-        This may well mean it has to leave alone. small areas the application wished to be
-        drawn.
-  </para>
-  <para>
-        Our example card uses chromakey so does not have to address most of the
-        clipping.  We will add a video_window structure to our global variables to
-        remember our parameters, as we did with the frame buffer.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCGWIN:
-                {
-                        if(copy_to_user(arg, &amp;capture_win, 
-                            sizeof(capture_win)))
-                                return -EFAULT;
-                        return 0;
-                }
-
-
-                case VIDIOCSWIN:
-                {
-                        struct video_window v;
-                        if(copy_from_user(&amp;v, arg, sizeof(v)))
-                                return -EFAULT;
-                        if(v.width &gt; 640 || v.height &gt; 480)
-                                return -EINVAL;
-                        if(v.width &lt; 16 || v.height &lt; 16)
-                                return -EINVAL;
-                        hardware_set_key(v.chromakey);
-                        hardware_set_window(v);
-                        memcpy(&amp;capture_win, &amp;v, sizeof(v));
-                        capture_w = v.width;
-                        capture_h = v.height;
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        Because we are using Chromakey our setup is fairly simple. Mostly we have to
-        check the values are sane and load them into the capture card.
-  </para>
-  <para>
-        With all the setup done we can now turn on the actual capture/overlay. This
-        is done with the VIDIOCCAPTURE ioctl. This takes a single integer argument
-        where 0 is on and 1 is off.
-  </para>
-  <programlisting>
-
-
-                case VIDIOCCAPTURE:
-                {
-                        int v;
-                        if(get_user(v, (int *)arg))
-                                return -EFAULT;
-                        if(v==0)
-                                hardware_capture_off();
-                        else
-                        {
-                                if(capture_fb.width == 0 
-                                    || capture_w == 0)
-                                        return -EINVAL;
-                                hardware_capture_on();
-                        }
-                        return 0;
-                }
-
-
-  </programlisting>
-  <para>
-        We grab the flag from user space and either enable or disable according to
-        its value. There is one small corner case we have to consider here. Suppose
-        that the capture was requested before the video window or the frame buffer
-        had been set up. In those cases there will be unconfigured fields in our
-        card data, as well as unconfigured hardware settings. We check for this case and
-        return an error if the frame buffer or the capture window width is zero.
-  </para>
-  <programlisting>
-
-
-                default:
-                        return -ENOIOCTLCMD;
-        }
-}
-  </programlisting>
-  <para>
-
-        We don't need to support any other ioctls, so if we get this far, it is time
-        to tell the video layer that we don't now what the user is talking about.
-  </para>
-  </sect1>
-  <sect1 id="endvid">
-  <title>Other Functionality</title>
-  <para>
-        The Video4Linux layer supports additional features, including a high
-        performance mmap() based capture mode and capturing part of the image. 
-        These features are out of the scope of the book.  You should however have enough 
-        example code to implement most simple video4linux devices for radio and TV
-        cards.
-  </para>
-  </sect1>
-  </chapter>
-  <chapter id="bugs">
-     <title>Known Bugs And Assumptions</title>
-  <para>
-  <variablelist>
-    <varlistentry><term>Multiple Opens</term>
-    <listitem>
-    <para>
-        The driver assumes multiple opens should not be allowed. A driver
-        can work around this but not cleanly.
-    </para>
-    </listitem></varlistentry>
-
-    <varlistentry><term>API Deficiencies</term>
-    <listitem>
-    <para>
-        The existing API poorly reflects compression capable devices. There
-        are plans afoot to merge V4L, V4L2 and some other ideas into a
-        better interface.
-    </para>
-    </listitem></varlistentry>
-  </variablelist>
-
-  </para>
-  </chapter>
-
-  <chapter id="pubfunctions">
-     <title>Public Functions Provided</title>
-!Edrivers/media/video/v4l2-dev.c
-  </chapter>
-
-</book>

Documentation/DocBook/wanbook.tmpl

@@ -1,99 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN"
-	"http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
-
-<book id="WANGuide">
- <bookinfo>
-  <title>Synchronous PPP and Cisco HDLC Programming Guide</title>
-  
-  <authorgroup>
-   <author>
-    <firstname>Alan</firstname>
-    <surname>Cox</surname>
-    <affiliation>
-     <address>
-      <email>alan@redhat.com</email>
-     </address>
-    </affiliation>
-   </author>
-  </authorgroup>
-
-  <copyright>
-   <year>2000</year>
-   <holder>Alan Cox</holder>
-  </copyright>
-
-  <legalnotice>
-   <para>
-     This documentation is free software; you can redistribute
-     it and/or modify it under the terms of the GNU General Public
-     License as published by the Free Software Foundation; either
-     version 2 of the License, or (at your option) any later
-     version.
-   </para>
-      
-   <para>
-     This program is distributed in the hope that it will be
-     useful, but WITHOUT ANY WARRANTY; without even the implied
-     warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-     See the GNU General Public License for more details.
-   </para>
-      
-   <para>
-     You should have received a copy of the GNU General Public
-     License along with this program; if not, write to the Free
-     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston,
-     MA 02111-1307 USA
-   </para>
-      
-   <para>
-     For more details see the file COPYING in the source
-     distribution of Linux.
-   </para>
-  </legalnotice>
- </bookinfo>
-
-<toc></toc>
-
-  <chapter id="intro">
-      <title>Introduction</title>
-  <para>
-	The syncppp drivers in Linux provide a fairly complete 
-	implementation of Cisco HDLC and a minimal implementation of
-	PPP. The longer term goal is to switch the PPP layer to the
-	generic PPP interface that is new in Linux 2.3.x. The API should
-	remain unchanged when this is done, but support will then be
-	available for IPX, compression and other PPP features
-  </para>
-  </chapter>
-  <chapter id="bugs">
-     <title>Known Bugs And Assumptions</title>
-  <para>
-  <variablelist>
-    <varlistentry><term>PPP is minimal</term>
-    <listitem>
-    <para>
-	The current PPP implementation is very basic, although sufficient
-	for most wan usages.
-    </para>
-    </listitem></varlistentry>
-
-    <varlistentry><term>Cisco HDLC Quirks</term>
-    <listitem>
-    <para>
-	Currently we do not end all packets with the correct Cisco multicast
-	or unicast flags. Nothing appears to mind too much but this should
-	be corrected.
-    </para>
-    </listitem></varlistentry>
-  </variablelist>
-	
-  </para>
-  </chapter>
-
-  <chapter id="pubfunctions">
-     <title>Public Functions Provided</title>
-!Edrivers/net/wan/syncppp.c
-  </chapter>
-
-</book>

Documentation/DocBook/z8530book.tmpl

@@ -12,7 +12,7 @@
     <surname>Cox</surname>
     <affiliation>
      <address>
-      <email>alan@redhat.com</email>
+      <email>alan@lxorguk.ukuu.org.uk</email>
      </address>
     </affiliation>
    </author>

Documentation/HOWTO

@@ -112,7 +112,7 @@ required reading:
 
     Other excellent descriptions of how to create patches properly are:
 	"The Perfect Patch"
-		http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt
+		http://userweb.kernel.org/~akpm/stuff/tpp.txt
 	"Linux kernel patch submission format"
 		http://linux.yyz.us/patch-format.html
 
@@ -620,7 +620,7 @@ all time.  It should describe the patch completely, containing:
 For more details on what this should all look like, please see the
 ChangeLog section of the document:
   "The Perfect Patch"
-      http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt
+      http://userweb.kernel.org/~akpm/stuff/tpp.txt
 
 
 

Documentation/MSI-HOWTO.txt

@@ -1,511 +0,0 @@
-		The MSI Driver Guide HOWTO
-	Tom L Nguyen tom.l.nguyen@intel.com
-			10/03/2003
-	Revised Feb 12, 2004 by Martine Silbermann
-		email: Martine.Silbermann@hp.com
-	Revised Jun 25, 2004 by Tom L Nguyen
-
-1. About this guide
-
-This guide describes the basics of Message Signaled Interrupts (MSI),
-the advantages of using MSI over traditional interrupt mechanisms,
-and how to enable your driver to use MSI or MSI-X. Also included is
-a Frequently Asked Questions (FAQ) section.
-
-1.1 Terminology
-
-PCI devices can be single-function or multi-function.  In either case,
-when this text talks about enabling or disabling MSI on a "device
-function," it is referring to one specific PCI device and function and
-not to all functions on a PCI device (unless the PCI device has only
-one function).
-
-2. Copyright 2003 Intel Corporation
-
-3. What is MSI/MSI-X?
-
-Message Signaled Interrupt (MSI), as described in the PCI Local Bus
-Specification Revision 2.3 or later, is an optional feature, and a
-required feature for PCI Express devices. MSI enables a device function
-to request service by sending an Inbound Memory Write on its PCI bus to
-the FSB as a Message Signal Interrupt transaction. Because MSI is
-generated in the form of a Memory Write, all transaction conditions,
-such as a Retry, Master-Abort, Target-Abort or normal completion, are
-supported.
-
-A PCI device that supports MSI must also support pin IRQ assertion
-interrupt mechanism to provide backward compatibility for systems that
-do not support MSI. In systems which support MSI, the bus driver is
-responsible for initializing the message address and message data of
-the device function's MSI/MSI-X capability structure during device
-initial configuration.
-
-An MSI capable device function indicates MSI support by implementing
-the MSI/MSI-X capability structure in its PCI capability list. The
-device function may implement both the MSI capability structure and
-the MSI-X capability structure; however, the bus driver should not
-enable both.
-
-The MSI capability structure contains Message Control register,
-Message Address register and Message Data register. These registers
-provide the bus driver control over MSI. The Message Control register
-indicates the MSI capability supported by the device. The Message
-Address register specifies the target address and the Message Data
-register specifies the characteristics of the message. To request
-service, the device function writes the content of the Message Data
-register to the target address. The device and its software driver
-are prohibited from writing to these registers.
-
-The MSI-X capability structure is an optional extension to MSI. It
-uses an independent and separate capability structure. There are
-some key advantages to implementing the MSI-X capability structure
-over the MSI capability structure as described below.
-
-	- Support a larger maximum number of vectors per function.
-
-	- Provide the ability for system software to configure
-	each vector with an independent message address and message
-	data, specified by a table that resides in Memory Space.
-
-        - MSI and MSI-X both support per-vector masking. Per-vector
-	masking is an optional extension of MSI but a required
-	feature for MSI-X. Per-vector masking provides the kernel the
-	ability to mask/unmask a single MSI while running its
-	interrupt service routine. If per-vector masking is
-	not supported, then the device driver should provide the
-	hardware/software synchronization to ensure that the device
-	generates MSI when the driver wants it to do so.
-
-4. Why use MSI?
-
-As a benefit to the simplification of board design, MSI allows board
-designers to remove out-of-band interrupt routing. MSI is another
-step towards a legacy-free environment.
-
-Due to increasing pressure on chipset and processor packages to
-reduce pin count, the need for interrupt pins is expected to
-diminish over time. Devices, due to pin constraints, may implement
-messages to increase performance.
-
-PCI Express endpoints uses INTx emulation (in-band messages) instead
-of IRQ pin assertion. Using INTx emulation requires interrupt
-sharing among devices connected to the same node (PCI bridge) while
-MSI is unique (non-shared) and does not require BIOS configuration
-support. As a result, the PCI Express technology requires MSI
-support for better interrupt performance.
-
-Using MSI enables the device functions to support two or more
-vectors, which can be configured to target different CPUs to
-increase scalability.
-
-5. Configuring a driver to use MSI/MSI-X
-
-By default, the kernel will not enable MSI/MSI-X on all devices that
-support this capability. The CONFIG_PCI_MSI kernel option
-must be selected to enable MSI/MSI-X support.
-
-5.1 Including MSI/MSI-X support into the kernel
-
-To allow MSI/MSI-X capable device drivers to selectively enable
-MSI/MSI-X (using pci_enable_msi()/pci_enable_msix() as described
-below), the VECTOR based scheme needs to be enabled by setting
-CONFIG_PCI_MSI during kernel config.
-
-Since the target of the inbound message is the local APIC, providing
-CONFIG_X86_LOCAL_APIC must be enabled as well as CONFIG_PCI_MSI.
-
-5.2 Configuring for MSI support
-
-Due to the non-contiguous fashion in vector assignment of the
-existing Linux kernel, this version does not support multiple
-messages regardless of a device function is capable of supporting
-more than one vector. To enable MSI on a device function's MSI
-capability structure requires a device driver to call the function
-pci_enable_msi() explicitly.
-
-5.2.1 API pci_enable_msi
-
-int pci_enable_msi(struct pci_dev *dev)
-
-With this new API, a device driver that wants to have MSI
-enabled on its device function must call this API to enable MSI.
-A successful call will initialize the MSI capability structure
-with ONE vector, regardless of whether a device function is
-capable of supporting multiple messages. This vector replaces the
-pre-assigned dev->irq with a new MSI vector. To avoid a conflict
-of the new assigned vector with existing pre-assigned vector requires
-a device driver to call this API before calling request_irq().
-
-5.2.2 API pci_disable_msi
-
-void pci_disable_msi(struct pci_dev *dev)
-
-This API should always be used to undo the effect of pci_enable_msi()
-when a device driver is unloading. This API restores dev->irq with
-the pre-assigned IOAPIC vector and switches a device's interrupt
-mode to PCI pin-irq assertion/INTx emulation mode.
-
-Note that a device driver should always call free_irq() on the MSI vector
-that it has done request_irq() on before calling this API. Failure to do
-so results in a BUG_ON() and a device will be left with MSI enabled and
-leaks its vector.
-
-5.2.3 MSI mode vs. legacy mode diagram
-
-The below diagram shows the events which switch the interrupt
-mode on the MSI-capable device function between MSI mode and
-PIN-IRQ assertion mode.
-
-	 ------------   pci_enable_msi 	 ------------------------
-	|	     | <===============	| 			 |
-	| MSI MODE   |	  	     	| PIN-IRQ ASSERTION MODE |
-	| 	     | ===============>	|			 |
- 	 ------------	pci_disable_msi  ------------------------
-
-
-Figure 1. MSI Mode vs. Legacy Mode
-
-In Figure 1, a device operates by default in legacy mode. Legacy
-in this context means PCI pin-irq assertion or PCI-Express INTx
-emulation. A successful MSI request (using pci_enable_msi()) switches
-a device's interrupt mode to MSI mode. A pre-assigned IOAPIC vector
-stored in dev->irq will be saved by the PCI subsystem and a new
-assigned MSI vector will replace dev->irq.
-
-To return back to its default mode, a device driver should always call
-pci_disable_msi() to undo the effect of pci_enable_msi(). Note that a
-device driver should always call free_irq() on the MSI vector it has
-done request_irq() on before calling pci_disable_msi(). Failure to do
-so results in a BUG_ON() and a device will be left with MSI enabled and
-leaks its vector. Otherwise, the PCI subsystem restores a device's
-dev->irq with a pre-assigned IOAPIC vector and marks the released
-MSI vector as unused.
-
-Once being marked as unused, there is no guarantee that the PCI
-subsystem will reserve this MSI vector for a device. Depending on
-the availability of current PCI vector resources and the number of
-MSI/MSI-X requests from other drivers, this MSI may be re-assigned.
-
-For the case where the PCI subsystem re-assigns this MSI vector to
-another driver, a request to switch back to MSI mode may result
-in being assigned a different MSI vector or a failure if no more
-vectors are available.
-
-5.3 Configuring for MSI-X support
-
-Due to the ability of the system software to configure each vector of
-the MSI-X capability structure with an independent message address
-and message data, the non-contiguous fashion in vector assignment of
-the existing Linux kernel has no impact on supporting multiple
-messages on an MSI-X capable device functions. To enable MSI-X on
-a device function's MSI-X capability structure requires its device
-driver to call the function pci_enable_msix() explicitly.
-
-The function pci_enable_msix(), once invoked, enables either
-all or nothing, depending on the current availability of PCI vector
-resources. If the PCI vector resources are available for the number
-of vectors requested by a device driver, this function will configure
-the MSI-X table of the MSI-X capability structure of a device with
-requested messages. To emphasize this reason, for example, a device
-may be capable for supporting the maximum of 32 vectors while its
-software driver usually may request 4 vectors. It is recommended
-that the device driver should call this function once during the
-initialization phase of the device driver.
-
-Unlike the function pci_enable_msi(), the function pci_enable_msix()
-does not replace the pre-assigned IOAPIC dev->irq with a new MSI
-vector because the PCI subsystem writes the 1:1 vector-to-entry mapping
-into the field vector of each element contained in a second argument.
-Note that the pre-assigned IOAPIC dev->irq is valid only if the device
-operates in PIN-IRQ assertion mode. In MSI-X mode, any attempt at
-using dev->irq by the device driver to request for interrupt service
-may result in unpredictable behavior.
-
-For each MSI-X vector granted, a device driver is responsible for calling
-other functions like request_irq(), enable_irq(), etc. to enable
-this vector with its corresponding interrupt service handler. It is
-a device driver's choice to assign all vectors with the same
-interrupt service handler or each vector with a unique interrupt
-service handler.
-
-5.3.1 Handling MMIO address space of MSI-X Table
-
-The PCI 3.0 specification has implementation notes that MMIO address
-space for a device's MSI-X structure should be isolated so that the
-software system can set different pages for controlling accesses to the
-MSI-X structure. The implementation of MSI support requires the PCI
-subsystem, not a device driver, to maintain full control of the MSI-X
-table/MSI-X PBA (Pending Bit Array) and MMIO address space of the MSI-X
-table/MSI-X PBA.  A device driver is prohibited from requesting the MMIO
-address space of the MSI-X table/MSI-X PBA. Otherwise, the PCI subsystem
-will fail enabling MSI-X on its hardware device when it calls the function
-pci_enable_msix().
-
-5.3.2 API pci_enable_msix
-
-int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
-
-This API enables a device driver to request the PCI subsystem
-to enable MSI-X messages on its hardware device. Depending on
-the availability of PCI vectors resources, the PCI subsystem enables
-either all or none of the requested vectors.
-
-Argument 'dev' points to the device (pci_dev) structure.
-
-Argument 'entries' is a pointer to an array of msix_entry structs.
-The number of entries is indicated in argument 'nvec'.
-struct msix_entry is defined in /driver/pci/msi.h:
-
-struct msix_entry {
-	u16 	vector; /* kernel uses to write alloc vector */
-	u16	entry; /* driver uses to specify entry */
-};
-
-A device driver is responsible for initializing the field 'entry' of
-each element with a unique entry supported by MSI-X table. Otherwise,
--EINVAL will be returned as a result. A successful return of zero
-indicates the PCI subsystem completed initializing each of the requested
-entries of the MSI-X table with message address and message data.
-Last but not least, the PCI subsystem will write the 1:1
-vector-to-entry mapping into the field 'vector' of each element. A
-device driver is responsible for keeping track of allocated MSI-X
-vectors in its internal data structure.
-
-A return of zero indicates that the number of MSI-X vectors was
-successfully allocated. A return of greater than zero indicates
-MSI-X vector shortage. Or a return of less than zero indicates
-a failure. This failure may be a result of duplicate entries
-specified in second argument, or a result of no available vector,
-or a result of failing to initialize MSI-X table entries.
-
-5.3.3 API pci_disable_msix
-
-void pci_disable_msix(struct pci_dev *dev)
-
-This API should always be used to undo the effect of pci_enable_msix()
-when a device driver is unloading. Note that a device driver should
-always call free_irq() on all MSI-X vectors it has done request_irq()
-on before calling this API. Failure to do so results in a BUG_ON() and
-a device will be left with MSI-X enabled and leaks its vectors.
-
-5.3.4 MSI-X mode vs. legacy mode diagram
-
-The below diagram shows the events which switch the interrupt
-mode on the MSI-X capable device function between MSI-X mode and
-PIN-IRQ assertion mode (legacy).
-
-	 ------------   pci_enable_msix(,,n) ------------------------
-	|	     | <===============	    | 			     |
-	| MSI-X MODE |	  	     	    | PIN-IRQ ASSERTION MODE |
-	| 	     | ===============>	    |			     |
- 	 ------------	pci_disable_msix     ------------------------
-
-Figure 2. MSI-X Mode vs. Legacy Mode
-
-In Figure 2, a device operates by default in legacy mode. A
-successful MSI-X request (using pci_enable_msix()) switches a
-device's interrupt mode to MSI-X mode. A pre-assigned IOAPIC vector
-stored in dev->irq will be saved by the PCI subsystem; however,
-unlike MSI mode, the PCI subsystem will not replace dev->irq with
-assigned MSI-X vector because the PCI subsystem already writes the 1:1
-vector-to-entry mapping into the field 'vector' of each element
-specified in second argument.
-
-To return back to its default mode, a device driver should always call
-pci_disable_msix() to undo the effect of pci_enable_msix(). Note that
-a device driver should always call free_irq() on all MSI-X vectors it
-has done request_irq() on before calling pci_disable_msix(). Failure
-to do so results in a BUG_ON() and a device will be left with MSI-X
-enabled and leaks its vectors. Otherwise, the PCI subsystem switches a
-device function's interrupt mode from MSI-X mode to legacy mode and
-marks all allocated MSI-X vectors as unused.
-
-Once being marked as unused, there is no guarantee that the PCI
-subsystem will reserve these MSI-X vectors for a device. Depending on
-the availability of current PCI vector resources and the number of
-MSI/MSI-X requests from other drivers, these MSI-X vectors may be
-re-assigned.
-
-For the case where the PCI subsystem re-assigned these MSI-X vectors
-to other drivers, a request to switch back to MSI-X mode may result
-being assigned with another set of MSI-X vectors or a failure if no
-more vectors are available.
-
-5.4 Handling function implementing both MSI and MSI-X capabilities
-
-For the case where a function implements both MSI and MSI-X
-capabilities, the PCI subsystem enables a device to run either in MSI
-mode or MSI-X mode but not both. A device driver determines whether it
-wants MSI or MSI-X enabled on its hardware device. Once a device
-driver requests for MSI, for example, it is prohibited from requesting
-MSI-X; in other words, a device driver is not permitted to ping-pong
-between MSI mod MSI-X mode during a run-time.
-
-5.5 Hardware requirements for MSI/MSI-X support
-
-MSI/MSI-X support requires support from both system hardware and
-individual hardware device functions.
-
-5.5.1 Required x86 hardware support
-
-Since the target of MSI address is the local APIC CPU, enabling
-MSI/MSI-X support in the Linux kernel is dependent on whether existing
-system hardware supports local APIC. Users should verify that their
-system supports local APIC operation by testing that it runs when
-CONFIG_X86_LOCAL_APIC=y.
-
-In SMP environment, CONFIG_X86_LOCAL_APIC is automatically set;
-however, in UP environment, users must manually set
-CONFIG_X86_LOCAL_APIC. Once CONFIG_X86_LOCAL_APIC=y, setting
-CONFIG_PCI_MSI enables the VECTOR based scheme and the option for
-MSI-capable device drivers to selectively enable MSI/MSI-X.
-
-Note that CONFIG_X86_IO_APIC setting is irrelevant because MSI/MSI-X
-vector is allocated new during runtime and MSI/MSI-X support does not
-depend on BIOS support. This key independency enables MSI/MSI-X
-support on future IOxAPIC free platforms.
-
-5.5.2 Device hardware support
-
-The hardware device function supports MSI by indicating the
-MSI/MSI-X capability structure on its PCI capability list. By
-default, this capability structure will not be initialized by
-the kernel to enable MSI during the system boot. In other words,
-the device function is running on its default pin assertion mode.
-Note that in many cases the hardware supporting MSI have bugs,
-which may result in system hangs. The software driver of specific
-MSI-capable hardware is responsible for deciding whether to call
-pci_enable_msi or not. A return of zero indicates the kernel
-successfully initialized the MSI/MSI-X capability structure of the
-device function. The device function is now running on MSI/MSI-X mode.
-
-5.6 How to tell whether MSI/MSI-X is enabled on device function
-
-At the driver level, a return of zero from the function call of
-pci_enable_msi()/pci_enable_msix() indicates to a device driver that
-its device function is initialized successfully and ready to run in
-MSI/MSI-X mode.
-
-At the user level, users can use the command 'cat /proc/interrupts'
-to display the vectors allocated for devices and their interrupt
-MSI/MSI-X modes ("PCI-MSI"/"PCI-MSI-X"). Below shows MSI mode is
-enabled on a SCSI Adaptec 39320D Ultra320 controller.
-
-           CPU0       CPU1
-  0:     324639          0    IO-APIC-edge  timer
-  1:       1186          0    IO-APIC-edge  i8042
-  2:          0          0          XT-PIC  cascade
- 12:       2797          0    IO-APIC-edge  i8042
- 14:       6543          0    IO-APIC-edge  ide0
- 15:          1          0    IO-APIC-edge  ide1
-169:          0          0   IO-APIC-level  uhci-hcd
-185:          0          0   IO-APIC-level  uhci-hcd
-193:        138         10         PCI-MSI  aic79xx
-201:         30          0         PCI-MSI  aic79xx
-225:         30          0   IO-APIC-level  aic7xxx
-233:         30          0   IO-APIC-level  aic7xxx
-NMI:          0          0
-LOC:     324553     325068
-ERR:          0
-MIS:          0
-
-6. MSI quirks
-
-Several PCI chipsets or devices are known to not support MSI.
-The PCI stack provides 3 possible levels of MSI disabling:
-* on a single device
-* on all devices behind a specific bridge
-* globally
-
-6.1. Disabling MSI on a single device
-
-Under some circumstances it might be required to disable MSI on a
-single device.  This may be achieved by either not calling pci_enable_msi()
-or all, or setting the pci_dev->no_msi flag before (most of the time
-in a quirk).
-
-6.2. Disabling MSI below a bridge
-
-The vast majority of MSI quirks are required by PCI bridges not
-being able to route MSI between busses. In this case, MSI have to be
-disabled on all devices behind this bridge. It is achieves by setting
-the PCI_BUS_FLAGS_NO_MSI flag in the pci_bus->bus_flags of the bridge
-subordinate bus. There is no need to set the same flag on bridges that
-are below the broken bridge. When pci_enable_msi() is called to enable
-MSI on a device, pci_msi_supported() takes care of checking the NO_MSI
-flag in all parent busses of the device.
-
-Some bridges actually support dynamic MSI support enabling/disabling
-by changing some bits in their PCI configuration space (especially
-the Hypertransport chipsets such as the nVidia nForce and Serverworks
-HT2000). It may then be required to update the NO_MSI flag on the
-corresponding devices in the sysfs hierarchy. To enable MSI support
-on device "0000:00:0e", do:
-
-	echo 1 > /sys/bus/pci/devices/0000:00:0e/msi_bus
-
-To disable MSI support, echo 0 instead of 1. Note that it should be
-used with caution since changing this value might break interrupts.
-
-6.3. Disabling MSI globally
-
-Some extreme cases may require to disable MSI globally on the system.
-For now, the only known case is a Serverworks PCI-X chipsets (MSI are
-not supported on several busses that are not all connected to the
-chipset in the Linux PCI hierarchy). In the vast majority of other
-cases, disabling only behind a specific bridge is enough.
-
-For debugging purpose, the user may also pass pci=nomsi on the kernel
-command-line to explicitly disable MSI globally. But, once the appro-
-priate quirks are added to the kernel, this option should not be
-required anymore.
-
-6.4. Finding why MSI cannot be enabled on a device
-
-Assuming that MSI are not enabled on a device, you should look at
-dmesg to find messages that quirks may output when disabling MSI
-on some devices, some bridges or even globally.
-Then, lspci -t gives the list of bridges above a device. Reading
-/sys/bus/pci/devices/0000:00:0e/msi_bus will tell you whether MSI
-are enabled (1) or disabled (0). In 0 is found in a single bridge
-msi_bus file above the device, MSI cannot be enabled.
-
-7. FAQ
-
-Q1. Are there any limitations on using the MSI?
-
-A1. If the PCI device supports MSI and conforms to the
-specification and the platform supports the APIC local bus,
-then using MSI should work.
-
-Q2. Will it work on all the Pentium processors (P3, P4, Xeon,
-AMD processors)? In P3 IPI's are transmitted on the APIC local
-bus and in P4 and Xeon they are transmitted on the system
-bus. Are there any implications with this?
-
-A2. MSI support enables a PCI device sending an inbound
-memory write (0xfeexxxxx as target address) on its PCI bus
-directly to the FSB. Since the message address has a
-redirection hint bit cleared, it should work.
-
-Q3. The target address 0xfeexxxxx will be translated by the
-Host Bridge into an interrupt message. Are there any
-limitations on the chipsets such as Intel 8xx, Intel e7xxx,
-or VIA?
-
-A3. If these chipsets support an inbound memory write with
-target address set as 0xfeexxxxx, as conformed to PCI
-specification 2.3 or latest, then it should work.
-
-Q4. From the driver point of view, if the MSI is lost because
-of errors occurring during inbound memory write, then it may
-wait forever. Is there a mechanism for it to recover?
-
-A4. Since the target of the transaction is an inbound memory
-write, all transaction termination conditions (Retry,
-Master-Abort, Target-Abort, or normal completion) are
-supported. A device sending an MSI must abide by all the PCI
-rules and conditions regarding that inbound memory write. So,
-if a retry is signaled it must retry, etc... We believe that
-the recommendation for Abort is also a retry (refer to PCI
-specification 2.3 or latest).

Documentation/ManagementStyle

@@ -17,7 +17,7 @@ companies.  If you sign purchase orders or you have any clue about the
 budget of your group, you're almost certainly not a kernel manager. 
 These suggestions may or may not apply to you. 
 
-First off, I'd suggest buying "Seven Habits of Highly Successful
+First off, I'd suggest buying "Seven Habits of Highly Effective
 People", and NOT read it.  Burn it, it's a great symbolic gesture. 
 
 (*) This document does so not so much by answering the question, but by

Documentation/PCI/00-INDEX

@@ -1,5 +1,7 @@
 00-INDEX
 	- this file
+MSI-HOWTO.txt
+	- the Message Signaled Interrupts (MSI) Driver Guide HOWTO and FAQ.
 PCI-DMA-mapping.txt
 	- info for PCI drivers using DMA portably across all platforms
 PCIEBUS-HOWTO.txt

Documentation/PCI/MSI-HOWTO.txt

@@ -0,0 +1,509 @@
+		The MSI Driver Guide HOWTO
+	Tom L Nguyen tom.l.nguyen@intel.com
+			10/03/2003
+	Revised Feb 12, 2004 by Martine Silbermann
+		email: Martine.Silbermann@hp.com
+	Revised Jun 25, 2004 by Tom L Nguyen
+
+1. About this guide
+
+This guide describes the basics of Message Signaled Interrupts (MSI),
+the advantages of using MSI over traditional interrupt mechanisms,
+and how to enable your driver to use MSI or MSI-X. Also included is
+a Frequently Asked Questions (FAQ) section.
+
+1.1 Terminology
+
+PCI devices can be single-function or multi-function.  In either case,
+when this text talks about enabling or disabling MSI on a "device
+function," it is referring to one specific PCI device and function and
+not to all functions on a PCI device (unless the PCI device has only
+one function).
+
+2. Copyright 2003 Intel Corporation
+
+3. What is MSI/MSI-X?
+
+Message Signaled Interrupt (MSI), as described in the PCI Local Bus
+Specification Revision 2.3 or later, is an optional feature, and a
+required feature for PCI Express devices. MSI enables a device function
+to request service by sending an Inbound Memory Write on its PCI bus to
+the FSB as a Message Signal Interrupt transaction. Because MSI is
+generated in the form of a Memory Write, all transaction conditions,
+such as a Retry, Master-Abort, Target-Abort or normal completion, are
+supported.
+
+A PCI device that supports MSI must also support pin IRQ assertion
+interrupt mechanism to provide backward compatibility for systems that
+do not support MSI. In systems which support MSI, the bus driver is
+responsible for initializing the message address and message data of
+the device function's MSI/MSI-X capability structure during device
+initial configuration.
+
+An MSI capable device function indicates MSI support by implementing
+the MSI/MSI-X capability structure in its PCI capability list. The
+device function may implement both the MSI capability structure and
+the MSI-X capability structure; however, the bus driver should not
+enable both.
+
+The MSI capability structure contains Message Control register,
+Message Address register and Message Data register. These registers
+provide the bus driver control over MSI. The Message Control register
+indicates the MSI capability supported by the device. The Message
+Address register specifies the target address and the Message Data
+register specifies the characteristics of the message. To request
+service, the device function writes the content of the Message Data
+register to the target address. The device and its software driver
+are prohibited from writing to these registers.
+
+The MSI-X capability structure is an optional extension to MSI. It
+uses an independent and separate capability structure. There are
+some key advantages to implementing the MSI-X capability structure
+over the MSI capability structure as described below.
+
+	- Support a larger maximum number of vectors per function.
+
+	- Provide the ability for system software to configure
+	each vector with an independent message address and message
+	data, specified by a table that resides in Memory Space.
+
+        - MSI and MSI-X both support per-vector masking. Per-vector
+	masking is an optional extension of MSI but a required
+	feature for MSI-X. Per-vector masking provides the kernel the
+	ability to mask/unmask a single MSI while running its
+	interrupt service routine. If per-vector masking is
+	not supported, then the device driver should provide the
+	hardware/software synchronization to ensure that the device
+	generates MSI when the driver wants it to do so.
+
+4. Why use MSI?
+
+As a benefit to the simplification of board design, MSI allows board
+designers to remove out-of-band interrupt routing. MSI is another
+step towards a legacy-free environment.
+
+Due to increasing pressure on chipset and processor packages to
+reduce pin count, the need for interrupt pins is expected to
+diminish over time. Devices, due to pin constraints, may implement
+messages to increase performance.
+
+PCI Express endpoints uses INTx emulation (in-band messages) instead
+of IRQ pin assertion. Using INTx emulation requires interrupt
+sharing among devices connected to the same node (PCI bridge) while
+MSI is unique (non-shared) and does not require BIOS configuration
+support. As a result, the PCI Express technology requires MSI
+support for better interrupt performance.
+
+Using MSI enables the device functions to support two or more
+vectors, which can be configured to target different CPUs to
+increase scalability.
+
+5. Configuring a driver to use MSI/MSI-X
+
+By default, the kernel will not enable MSI/MSI-X on all devices that
+support this capability. The CONFIG_PCI_MSI kernel option
+must be selected to enable MSI/MSI-X support.
+
+5.1 Including MSI/MSI-X support into the kernel
+
+To allow MSI/MSI-X capable device drivers to selectively enable
+MSI/MSI-X (using pci_enable_msi()/pci_enable_msix() as described
+below), the VECTOR based scheme needs to be enabled by setting
+CONFIG_PCI_MSI during kernel config.
+
+Since the target of the inbound message is the local APIC, providing
+CONFIG_X86_LOCAL_APIC must be enabled as well as CONFIG_PCI_MSI.
+
+5.2 Configuring for MSI support
+
+Due to the non-contiguous fashion in vector assignment of the
+existing Linux kernel, this version does not support multiple
+messages regardless of a device function is capable of supporting
+more than one vector. To enable MSI on a device function's MSI
+capability structure requires a device driver to call the function
+pci_enable_msi() explicitly.
+
+5.2.1 API pci_enable_msi
+
+int pci_enable_msi(struct pci_dev *dev)
+
+With this new API, a device driver that wants to have MSI
+enabled on its device function must call this API to enable MSI.
+A successful call will initialize the MSI capability structure
+with ONE vector, regardless of whether a device function is
+capable of supporting multiple messages. This vector replaces the
+pre-assigned dev->irq with a new MSI vector. To avoid a conflict
+of the new assigned vector with existing pre-assigned vector requires
+a device driver to call this API before calling request_irq().
+
+5.2.2 API pci_disable_msi
+
+void pci_disable_msi(struct pci_dev *dev)
+
+This API should always be used to undo the effect of pci_enable_msi()
+when a device driver is unloading. This API restores dev->irq with
+the pre-assigned IOAPIC vector and switches a device's interrupt
+mode to PCI pin-irq assertion/INTx emulation mode.
+
+Note that a device driver should always call free_irq() on the MSI vector
+that it has done request_irq() on before calling this API. Failure to do
+so results in a BUG_ON() and a device will be left with MSI enabled and
+leaks its vector.
+
+5.2.3 MSI mode vs. legacy mode diagram
+
+The below diagram shows the events which switch the interrupt
+mode on the MSI-capable device function between MSI mode and
+PIN-IRQ assertion mode.
+
+	 ------------   pci_enable_msi 	 ------------------------
+	|	     | <===============	| 			 |
+	| MSI MODE   |	  	     	| PIN-IRQ ASSERTION MODE |
+	| 	     | ===============>	|			 |
+ 	 ------------	pci_disable_msi  ------------------------
+
+
+Figure 1. MSI Mode vs. Legacy Mode
+
+In Figure 1, a device operates by default in legacy mode. Legacy
+in this context means PCI pin-irq assertion or PCI-Express INTx
+emulation. A successful MSI request (using pci_enable_msi()) switches
+a device's interrupt mode to MSI mode. A pre-assigned IOAPIC vector
+stored in dev->irq will be saved by the PCI subsystem and a new
+assigned MSI vector will replace dev->irq.
+
+To return back to its default mode, a device driver should always call
+pci_disable_msi() to undo the effect of pci_enable_msi(). Note that a
+device driver should always call free_irq() on the MSI vector it has
+done request_irq() on before calling pci_disable_msi(). Failure to do
+so results in a BUG_ON() and a device will be left with MSI enabled and
+leaks its vector. Otherwise, the PCI subsystem restores a device's
+dev->irq with a pre-assigned IOAPIC vector and marks the released
+MSI vector as unused.
+
+Once being marked as unused, there is no guarantee that the PCI
+subsystem will reserve this MSI vector for a device. Depending on
+the availability of current PCI vector resources and the number of
+MSI/MSI-X requests from other drivers, this MSI may be re-assigned.
+
+For the case where the PCI subsystem re-assigns this MSI vector to
+another driver, a request to switch back to MSI mode may result
+in being assigned a different MSI vector or a failure if no more
+vectors are available.
+
+5.3 Configuring for MSI-X support
+
+Due to the ability of the system software to configure each vector of
+the MSI-X capability structure with an independent message address
+and message data, the non-contiguous fashion in vector assignment of
+the existing Linux kernel has no impact on supporting multiple
+messages on an MSI-X capable device functions. To enable MSI-X on
+a device function's MSI-X capability structure requires its device
+driver to call the function pci_enable_msix() explicitly.
+
+The function pci_enable_msix(), once invoked, enables either
+all or nothing, depending on the current availability of PCI vector
+resources. If the PCI vector resources are available for the number
+of vectors requested by a device driver, this function will configure
+the MSI-X table of the MSI-X capability structure of a device with
+requested messages. To emphasize this reason, for example, a device
+may be capable for supporting the maximum of 32 vectors while its
+software driver usually may request 4 vectors. It is recommended
+that the device driver should call this function once during the
+initialization phase of the device driver.
+
+Unlike the function pci_enable_msi(), the function pci_enable_msix()
+does not replace the pre-assigned IOAPIC dev->irq with a new MSI
+vector because the PCI subsystem writes the 1:1 vector-to-entry mapping
+into the field vector of each element contained in a second argument.
+Note that the pre-assigned IOAPIC dev->irq is valid only if the device
+operates in PIN-IRQ assertion mode. In MSI-X mode, any attempt at
+using dev->irq by the device driver to request for interrupt service
+may result in unpredictable behavior.
+
+For each MSI-X vector granted, a device driver is responsible for calling
+other functions like request_irq(), enable_irq(), etc. to enable
+this vector with its corresponding interrupt service handler. It is
+a device driver's choice to assign all vectors with the same
+interrupt service handler or each vector with a unique interrupt
+service handler.
+
+5.3.1 Handling MMIO address space of MSI-X Table
+
+The PCI 3.0 specification has implementation notes that MMIO address
+space for a device's MSI-X structure should be isolated so that the
+software system can set different pages for controlling accesses to the
+MSI-X structure. The implementation of MSI support requires the PCI
+subsystem, not a device driver, to maintain full control of the MSI-X
+table/MSI-X PBA (Pending Bit Array) and MMIO address space of the MSI-X
+table/MSI-X PBA.  A device driver should not access the MMIO address
+space of the MSI-X table/MSI-X PBA.
+
+5.3.2 API pci_enable_msix
+
+int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec)
+
+This API enables a device driver to request the PCI subsystem
+to enable MSI-X messages on its hardware device. Depending on
+the availability of PCI vectors resources, the PCI subsystem enables
+either all or none of the requested vectors.
+
+Argument 'dev' points to the device (pci_dev) structure.
+
+Argument 'entries' is a pointer to an array of msix_entry structs.
+The number of entries is indicated in argument 'nvec'.
+struct msix_entry is defined in /driver/pci/msi.h:
+
+struct msix_entry {
+	u16 	vector; /* kernel uses to write alloc vector */
+	u16	entry; /* driver uses to specify entry */
+};
+
+A device driver is responsible for initializing the field 'entry' of
+each element with a unique entry supported by MSI-X table. Otherwise,
+-EINVAL will be returned as a result. A successful return of zero
+indicates the PCI subsystem completed initializing each of the requested
+entries of the MSI-X table with message address and message data.
+Last but not least, the PCI subsystem will write the 1:1
+vector-to-entry mapping into the field 'vector' of each element. A
+device driver is responsible for keeping track of allocated MSI-X
+vectors in its internal data structure.
+
+A return of zero indicates that the number of MSI-X vectors was
+successfully allocated. A return of greater than zero indicates
+MSI-X vector shortage. Or a return of less than zero indicates
+a failure. This failure may be a result of duplicate entries
+specified in second argument, or a result of no available vector,
+or a result of failing to initialize MSI-X table entries.
+
+5.3.3 API pci_disable_msix
+
+void pci_disable_msix(struct pci_dev *dev)
+
+This API should always be used to undo the effect of pci_enable_msix()
+when a device driver is unloading. Note that a device driver should
+always call free_irq() on all MSI-X vectors it has done request_irq()
+on before calling this API. Failure to do so results in a BUG_ON() and
+a device will be left with MSI-X enabled and leaks its vectors.
+
+5.3.4 MSI-X mode vs. legacy mode diagram
+
+The below diagram shows the events which switch the interrupt
+mode on the MSI-X capable device function between MSI-X mode and
+PIN-IRQ assertion mode (legacy).
+
+	 ------------   pci_enable_msix(,,n) ------------------------
+	|	     | <===============	    | 			     |
+	| MSI-X MODE |	  	     	    | PIN-IRQ ASSERTION MODE |
+	| 	     | ===============>	    |			     |
+ 	 ------------	pci_disable_msix     ------------------------
+
+Figure 2. MSI-X Mode vs. Legacy Mode
+
+In Figure 2, a device operates by default in legacy mode. A
+successful MSI-X request (using pci_enable_msix()) switches a
+device's interrupt mode to MSI-X mode. A pre-assigned IOAPIC vector
+stored in dev->irq will be saved by the PCI subsystem; however,
+unlike MSI mode, the PCI subsystem will not replace dev->irq with
+assigned MSI-X vector because the PCI subsystem already writes the 1:1
+vector-to-entry mapping into the field 'vector' of each element
+specified in second argument.
+
+To return back to its default mode, a device driver should always call
+pci_disable_msix() to undo the effect of pci_enable_msix(). Note that
+a device driver should always call free_irq() on all MSI-X vectors it
+has done request_irq() on before calling pci_disable_msix(). Failure
+to do so results in a BUG_ON() and a device will be left with MSI-X
+enabled and leaks its vectors. Otherwise, the PCI subsystem switches a
+device function's interrupt mode from MSI-X mode to legacy mode and
+marks all allocated MSI-X vectors as unused.
+
+Once being marked as unused, there is no guarantee that the PCI
+subsystem will reserve these MSI-X vectors for a device. Depending on
+the availability of current PCI vector resources and the number of
+MSI/MSI-X requests from other drivers, these MSI-X vectors may be
+re-assigned.
+
+For the case where the PCI subsystem re-assigned these MSI-X vectors
+to other drivers, a request to switch back to MSI-X mode may result
+being assigned with another set of MSI-X vectors or a failure if no
+more vectors are available.
+
+5.4 Handling function implementing both MSI and MSI-X capabilities
+
+For the case where a function implements both MSI and MSI-X
+capabilities, the PCI subsystem enables a device to run either in MSI
+mode or MSI-X mode but not both. A device driver determines whether it
+wants MSI or MSI-X enabled on its hardware device. Once a device
+driver requests for MSI, for example, it is prohibited from requesting
+MSI-X; in other words, a device driver is not permitted to ping-pong
+between MSI mod MSI-X mode during a run-time.
+
+5.5 Hardware requirements for MSI/MSI-X support
+
+MSI/MSI-X support requires support from both system hardware and
+individual hardware device functions.
+
+5.5.1 Required x86 hardware support
+
+Since the target of MSI address is the local APIC CPU, enabling
+MSI/MSI-X support in the Linux kernel is dependent on whether existing
+system hardware supports local APIC. Users should verify that their
+system supports local APIC operation by testing that it runs when
+CONFIG_X86_LOCAL_APIC=y.
+
+In SMP environment, CONFIG_X86_LOCAL_APIC is automatically set;
+however, in UP environment, users must manually set
+CONFIG_X86_LOCAL_APIC. Once CONFIG_X86_LOCAL_APIC=y, setting
+CONFIG_PCI_MSI enables the VECTOR based scheme and the option for
+MSI-capable device drivers to selectively enable MSI/MSI-X.
+
+Note that CONFIG_X86_IO_APIC setting is irrelevant because MSI/MSI-X
+vector is allocated new during runtime and MSI/MSI-X support does not
+depend on BIOS support. This key independency enables MSI/MSI-X
+support on future IOxAPIC free platforms.
+
+5.5.2 Device hardware support
+
+The hardware device function supports MSI by indicating the
+MSI/MSI-X capability structure on its PCI capability list. By
+default, this capability structure will not be initialized by
+the kernel to enable MSI during the system boot. In other words,
+the device function is running on its default pin assertion mode.
+Note that in many cases the hardware supporting MSI have bugs,
+which may result in system hangs. The software driver of specific
+MSI-capable hardware is responsible for deciding whether to call
+pci_enable_msi or not. A return of zero indicates the kernel
+successfully initialized the MSI/MSI-X capability structure of the
+device function. The device function is now running on MSI/MSI-X mode.
+
+5.6 How to tell whether MSI/MSI-X is enabled on device function
+
+At the driver level, a return of zero from the function call of
+pci_enable_msi()/pci_enable_msix() indicates to a device driver that
+its device function is initialized successfully and ready to run in
+MSI/MSI-X mode.
+
+At the user level, users can use the command 'cat /proc/interrupts'
+to display the vectors allocated for devices and their interrupt
+MSI/MSI-X modes ("PCI-MSI"/"PCI-MSI-X"). Below shows MSI mode is
+enabled on a SCSI Adaptec 39320D Ultra320 controller.
+
+           CPU0       CPU1
+  0:     324639          0    IO-APIC-edge  timer
+  1:       1186          0    IO-APIC-edge  i8042
+  2:          0          0          XT-PIC  cascade
+ 12:       2797          0    IO-APIC-edge  i8042
+ 14:       6543          0    IO-APIC-edge  ide0
+ 15:          1          0    IO-APIC-edge  ide1
+169:          0          0   IO-APIC-level  uhci-hcd
+185:          0          0   IO-APIC-level  uhci-hcd
+193:        138         10         PCI-MSI  aic79xx
+201:         30          0         PCI-MSI  aic79xx
+225:         30          0   IO-APIC-level  aic7xxx
+233:         30          0   IO-APIC-level  aic7xxx
+NMI:          0          0
+LOC:     324553     325068
+ERR:          0
+MIS:          0
+
+6. MSI quirks
+
+Several PCI chipsets or devices are known to not support MSI.
+The PCI stack provides 3 possible levels of MSI disabling:
+* on a single device
+* on all devices behind a specific bridge
+* globally
+
+6.1. Disabling MSI on a single device
+
+Under some circumstances it might be required to disable MSI on a
+single device.  This may be achieved by either not calling pci_enable_msi()
+or all, or setting the pci_dev->no_msi flag before (most of the time
+in a quirk).
+
+6.2. Disabling MSI below a bridge
+
+The vast majority of MSI quirks are required by PCI bridges not
+being able to route MSI between busses. In this case, MSI have to be
+disabled on all devices behind this bridge. It is achieves by setting
+the PCI_BUS_FLAGS_NO_MSI flag in the pci_bus->bus_flags of the bridge
+subordinate bus. There is no need to set the same flag on bridges that
+are below the broken bridge. When pci_enable_msi() is called to enable
+MSI on a device, pci_msi_supported() takes care of checking the NO_MSI
+flag in all parent busses of the device.
+
+Some bridges actually support dynamic MSI support enabling/disabling
+by changing some bits in their PCI configuration space (especially
+the Hypertransport chipsets such as the nVidia nForce and Serverworks
+HT2000). It may then be required to update the NO_MSI flag on the
+corresponding devices in the sysfs hierarchy. To enable MSI support
+on device "0000:00:0e", do:
+
+	echo 1 > /sys/bus/pci/devices/0000:00:0e/msi_bus
+
+To disable MSI support, echo 0 instead of 1. Note that it should be
+used with caution since changing this value might break interrupts.
+
+6.3. Disabling MSI globally
+
+Some extreme cases may require to disable MSI globally on the system.
+For now, the only known case is a Serverworks PCI-X chipsets (MSI are
+not supported on several busses that are not all connected to the
+chipset in the Linux PCI hierarchy). In the vast majority of other
+cases, disabling only behind a specific bridge is enough.
+
+For debugging purpose, the user may also pass pci=nomsi on the kernel
+command-line to explicitly disable MSI globally. But, once the appro-
+priate quirks are added to the kernel, this option should not be
+required anymore.
+
+6.4. Finding why MSI cannot be enabled on a device
+
+Assuming that MSI are not enabled on a device, you should look at
+dmesg to find messages that quirks may output when disabling MSI
+on some devices, some bridges or even globally.
+Then, lspci -t gives the list of bridges above a device. Reading
+/sys/bus/pci/devices/0000:00:0e/msi_bus will tell you whether MSI
+are enabled (1) or disabled (0). In 0 is found in a single bridge
+msi_bus file above the device, MSI cannot be enabled.
+
+7. FAQ
+
+Q1. Are there any limitations on using the MSI?
+
+A1. If the PCI device supports MSI and conforms to the
+specification and the platform supports the APIC local bus,
+then using MSI should work.
+
+Q2. Will it work on all the Pentium processors (P3, P4, Xeon,
+AMD processors)? In P3 IPI's are transmitted on the APIC local
+bus and in P4 and Xeon they are transmitted on the system
+bus. Are there any implications with this?
+
+A2. MSI support enables a PCI device sending an inbound
+memory write (0xfeexxxxx as target address) on its PCI bus
+directly to the FSB. Since the message address has a
+redirection hint bit cleared, it should work.
+
+Q3. The target address 0xfeexxxxx will be translated by the
+Host Bridge into an interrupt message. Are there any
+limitations on the chipsets such as Intel 8xx, Intel e7xxx,
+or VIA?
+
+A3. If these chipsets support an inbound memory write with
+target address set as 0xfeexxxxx, as conformed to PCI
+specification 2.3 or latest, then it should work.
+
+Q4. From the driver point of view, if the MSI is lost because
+of errors occurring during inbound memory write, then it may
+wait forever. Is there a mechanism for it to recover?
+
+A4. Since the target of the transaction is an inbound memory
+write, all transaction termination conditions (Retry,
+Master-Abort, Target-Abort, or normal completion) are
+supported. A device sending an MSI must abide by all the PCI
+rules and conditions regarding that inbound memory write. So,
+if a retry is signaled it must retry, etc... We believe that
+the recommendation for Abort is also a retry (refer to PCI
+specification 2.3 or latest).

Documentation/PCI/pci.txt

@@ -163,6 +163,10 @@ need pass only as many optional fields as necessary:
 	o class and classmask fields default to 0
 	o driver_data defaults to 0UL.
 
+Note that driver_data must match the value used by any of the pci_device_id
+entries defined in the driver. This makes the driver_data field mandatory
+if all the pci_device_id entries have a non-zero driver_data value.
+
 Once added, the driver probe routine will be invoked for any unclaimed
 PCI devices listed in its (newly updated) pci_ids list.
 

Documentation/PCI/pcieaer-howto.txt

@@ -203,22 +203,17 @@ to mmio_enabled.
 
 3.3 helper functions
 
-3.3.1 int pci_find_aer_capability(struct pci_dev *dev);
-pci_find_aer_capability locates the PCI Express AER capability
-in the device configuration space. If the device doesn't support
-PCI-Express AER, the function returns 0.
-
-3.3.2 int pci_enable_pcie_error_reporting(struct pci_dev *dev);
+3.3.1 int pci_enable_pcie_error_reporting(struct pci_dev *dev);
 pci_enable_pcie_error_reporting enables the device to send error
 messages to root port when an error is detected. Note that devices
 don't enable the error reporting by default, so device drivers need
 call this function to enable it.
 
-3.3.3 int pci_disable_pcie_error_reporting(struct pci_dev *dev);
+3.3.2 int pci_disable_pcie_error_reporting(struct pci_dev *dev);
 pci_disable_pcie_error_reporting disables the device to send error
 messages to root port when an error is detected.
 
-3.3.4 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
+3.3.3 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
 pci_cleanup_aer_uncorrect_error_status cleanups the uncorrectable
 error status register.
 

Documentation/RCU/00-INDEX

@@ -16,6 +16,8 @@ RTFP.txt
 	- List of RCU papers (bibliography) going back to 1980.
 torture.txt
 	- RCU Torture Test Operation (CONFIG_RCU_TORTURE_TEST)
+trace.txt
+	- CONFIG_RCU_TRACE debugfs files and formats
 UP.txt
 	- RCU on Uniprocessor Systems
 whatisRCU.txt

Documentation/RCU/rculist_nulls.txt

@@ -0,0 +1,167 @@
+Using hlist_nulls to protect read-mostly linked lists and
+objects using SLAB_DESTROY_BY_RCU allocations.
+
+Please read the basics in Documentation/RCU/listRCU.txt
+
+Using special makers (called 'nulls') is a convenient way
+to solve following problem :
+
+A typical RCU linked list managing objects which are
+allocated with SLAB_DESTROY_BY_RCU kmem_cache can
+use following algos :
+
+1) Lookup algo
+--------------
+rcu_read_lock()
+begin:
+obj = lockless_lookup(key);
+if (obj) {
+  if (!try_get_ref(obj)) // might fail for free objects
+    goto begin;
+  /*
+   * Because a writer could delete object, and a writer could
+   * reuse these object before the RCU grace period, we
+   * must check key after geting the reference on object
+   */
+  if (obj->key != key) { // not the object we expected
+     put_ref(obj);
+     goto begin;
+   }
+}
+rcu_read_unlock();
+
+Beware that lockless_lookup(key) cannot use traditional hlist_for_each_entry_rcu()
+but a version with an additional memory barrier (smp_rmb())
+
+lockless_lookup(key)
+{
+   struct hlist_node *node, *next;
+   for (pos = rcu_dereference((head)->first);
+          pos && ({ next = pos->next; smp_rmb(); prefetch(next); 1; }) &&
+          ({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; });
+          pos = rcu_dereference(next))
+      if (obj->key == key)
+         return obj;
+   return NULL;
+
+And note the traditional hlist_for_each_entry_rcu() misses this smp_rmb() :
+
+   struct hlist_node *node;
+   for (pos = rcu_dereference((head)->first);
+		pos && ({ prefetch(pos->next); 1; }) &&
+		({ tpos = hlist_entry(pos, typeof(*tpos), member); 1; });
+		pos = rcu_dereference(pos->next))
+      if (obj->key == key)
+         return obj;
+   return NULL;
+}
+
+Quoting Corey Minyard :
+
+"If the object is moved from one list to another list in-between the
+ time the hash is calculated and the next field is accessed, and the
+ object has moved to the end of a new list, the traversal will not
+ complete properly on the list it should have, since the object will
+ be on the end of the new list and there's not a way to tell it's on a
+ new list and restart the list traversal.  I think that this can be
+ solved by pre-fetching the "next" field (with proper barriers) before
+ checking the key."
+
+2) Insert algo :
+----------------
+
+We need to make sure a reader cannot read the new 'obj->obj_next' value
+and previous value of 'obj->key'. Or else, an item could be deleted
+from a chain, and inserted into another chain. If new chain was empty
+before the move, 'next' pointer is NULL, and lockless reader can
+not detect it missed following items in original chain.
+
+/*
+ * Please note that new inserts are done at the head of list,
+ * not in the middle or end.
+ */
+obj = kmem_cache_alloc(...);
+lock_chain(); // typically a spin_lock()
+obj->key = key;
+atomic_inc(&obj->refcnt);
+/*
+ * we need to make sure obj->key is updated before obj->next
+ */
+smp_wmb();
+hlist_add_head_rcu(&obj->obj_node, list);
+unlock_chain(); // typically a spin_unlock()
+
+
+3) Remove algo
+--------------
+Nothing special here, we can use a standard RCU hlist deletion.
+But thanks to SLAB_DESTROY_BY_RCU, beware a deleted object can be reused
+very very fast (before the end of RCU grace period)
+
+if (put_last_reference_on(obj) {
+   lock_chain(); // typically a spin_lock()
+   hlist_del_init_rcu(&obj->obj_node);
+   unlock_chain(); // typically a spin_unlock()
+   kmem_cache_free(cachep, obj);
+}
+
+
+
+--------------------------------------------------------------------------
+With hlist_nulls we can avoid extra smp_rmb() in lockless_lookup()
+and extra smp_wmb() in insert function.
+
+For example, if we choose to store the slot number as the 'nulls'
+end-of-list marker for each slot of the hash table, we can detect
+a race (some writer did a delete and/or a move of an object
+to another chain) checking the final 'nulls' value if
+the lookup met the end of chain. If final 'nulls' value
+is not the slot number, then we must restart the lookup at
+the begining. If the object was moved to same chain,
+then the reader doesnt care : It might eventually
+scan the list again without harm.
+
+
+1) lookup algo
+
+ head = &table[slot];
+ rcu_read_lock();
+begin:
+ hlist_nulls_for_each_entry_rcu(obj, node, head, member) {
+   if (obj->key == key) {
+      if (!try_get_ref(obj)) // might fail for free objects
+         goto begin;
+      if (obj->key != key) { // not the object we expected
+         put_ref(obj);
+         goto begin;
+      }
+  goto out;
+ }
+/*
+ * if the nulls value we got at the end of this lookup is
+ * not the expected one, we must restart lookup.
+ * We probably met an item that was moved to another chain.
+ */
+ if (get_nulls_value(node) != slot)
+   goto begin;
+ obj = NULL;
+
+out:
+ rcu_read_unlock();
+
+2) Insert function :
+--------------------
+
+/*
+ * Please note that new inserts are done at the head of list,
+ * not in the middle or end.
+ */
+obj = kmem_cache_alloc(cachep);
+lock_chain(); // typically a spin_lock()
+obj->key = key;
+atomic_set(&obj->refcnt, 1);
+/*
+ * insert obj in RCU way (readers might be traversing chain)
+ */
+hlist_nulls_add_head_rcu(&obj->obj_node, list);
+unlock_chain(); // typically a spin_unlock()

Documentation/RCU/trace.txt

@@ -0,0 +1,413 @@
+CONFIG_RCU_TRACE debugfs Files and Formats
+
+
+The rcupreempt and rcutree implementations of RCU provide debugfs trace
+output that summarizes counters and state.  This information is useful for
+debugging RCU itself, and can sometimes also help to debug abuses of RCU.
+Note that the rcuclassic implementation of RCU does not provide debugfs
+trace output.
+
+The following sections describe the debugfs files and formats for
+preemptable RCU (rcupreempt) and hierarchical RCU (rcutree).
+
+
+Preemptable RCU debugfs Files and Formats
+
+This implementation of RCU provides three debugfs files under the
+top-level directory RCU: rcu/rcuctrs (which displays the per-CPU
+counters used by preemptable RCU) rcu/rcugp (which displays grace-period
+counters), and rcu/rcustats (which internal counters for debugging RCU).
+
+The output of "cat rcu/rcuctrs" looks as follows:
+
+CPU last cur F M
+  0    5  -5 0 0
+  1   -1   0 0 0
+  2    0   1 0 0
+  3    0   1 0 0
+  4    0   1 0 0
+  5    0   1 0 0
+  6    0   2 0 0
+  7    0  -1 0 0
+  8    0   1 0 0
+ggp = 26226, state = waitzero
+
+The per-CPU fields are as follows:
+
+o	"CPU" gives the CPU number.  Offline CPUs are not displayed.
+
+o	"last" gives the value of the counter that is being decremented
+	for the current grace period phase.  In the example above,
+	the counters sum to 4, indicating that there are still four
+	RCU read-side critical sections still running that started
+	before the last counter flip.
+
+o	"cur" gives the value of the counter that is currently being
+	both incremented (by rcu_read_lock()) and decremented (by
+	rcu_read_unlock()).  In the example above, the counters sum to
+	1, indicating that there is only one RCU read-side critical section
+	still running that started after the last counter flip.
+
+o	"F" indicates whether RCU is waiting for this CPU to acknowledge
+	a counter flip.  In the above example, RCU is not waiting on any,
+	which is consistent with the state being "waitzero" rather than
+	"waitack".
+
+o	"M" indicates whether RCU is waiting for this CPU to execute a
+	memory barrier.  In the above example, RCU is not waiting on any,
+	which is consistent with the state being "waitzero" rather than
+	"waitmb".
+
+o	"ggp" is the global grace-period counter.
+
+o	"state" is the RCU state, which can be one of the following:
+
+	o	"idle": there is no grace period in progress.
+
+	o	"waitack": RCU just incremented the global grace-period
+		counter, which has the effect of reversing the roles of
+		the "last" and "cur" counters above, and is waiting for
+		all the CPUs to acknowledge the flip.  Once the flip has
+		been acknowledged, CPUs will no longer be incrementing
+		what are now the "last" counters, so that their sum will
+		decrease monotonically down to zero.
+
+	o	"waitzero": RCU is waiting for the sum of the "last" counters
+		to decrease to zero.
+
+	o	"waitmb": RCU is waiting for each CPU to execute a memory
+		barrier, which ensures that instructions from a given CPU's
+		last RCU read-side critical section cannot be reordered
+		with instructions following the memory-barrier instruction.
+
+The output of "cat rcu/rcugp" looks as follows:
+
+oldggp=48870  newggp=48873
+
+Note that reading from this file provokes a synchronize_rcu().  The
+"oldggp" value is that of "ggp" from rcu/rcuctrs above, taken before
+executing the synchronize_rcu(), and the "newggp" value is also the
+"ggp" value, but taken after the synchronize_rcu() command returns.
+
+
+The output of "cat rcu/rcugp" looks as follows:
+
+na=1337955 nl=40 wa=1337915 wl=44 da=1337871 dl=0 dr=1337871 di=1337871
+1=50989 e1=6138 i1=49722 ie1=82 g1=49640 a1=315203 ae1=265563 a2=49640
+z1=1401244 ze1=1351605 z2=49639 m1=5661253 me1=5611614 m2=49639
+
+These are counters tracking internal preemptable-RCU events, however,
+some of them may be useful for debugging algorithms using RCU.  In
+particular, the "nl", "wl", and "dl" values track the number of RCU
+callbacks in various states.  The fields are as follows:
+
+o	"na" is the total number of RCU callbacks that have been enqueued
+	since boot.
+
+o	"nl" is the number of RCU callbacks waiting for the previous
+	grace period to end so that they can start waiting on the next
+	grace period.
+
+o	"wa" is the total number of RCU callbacks that have started waiting
+	for a grace period since boot.  "na" should be roughly equal to
+	"nl" plus "wa".
+
+o	"wl" is the number of RCU callbacks currently waiting for their
+	grace period to end.
+
+o	"da" is the total number of RCU callbacks whose grace periods
+	have completed since boot.  "wa" should be roughly equal to
+	"wl" plus "da".
+
+o	"dr" is the total number of RCU callbacks that have been removed
+	from the list of callbacks ready to invoke.  "dr" should be roughly
+	equal to "da".
+
+o	"di" is the total number of RCU callbacks that have been invoked
+	since boot.  "di" should be roughly equal to "da", though some
+	early versions of preemptable RCU had a bug so that only the
+	last CPU's count of invocations was displayed, rather than the
+	sum of all CPU's counts.
+
+o	"1" is the number of calls to rcu_try_flip().  This should be
+	roughly equal to the sum of "e1", "i1", "a1", "z1", and "m1"
+	described below.  In other words, the number of times that
+	the state machine is visited should be equal to the sum of the
+	number of times that each state is visited plus the number of
+	times that the state-machine lock acquisition failed.
+
+o	"e1" is the number of times that rcu_try_flip() was unable to
+	acquire the fliplock.
+
+o	"i1" is the number of calls to rcu_try_flip_idle().
+
+o	"ie1" is the number of times rcu_try_flip_idle() exited early
+	due to the calling CPU having no work for RCU.
+
+o	"g1" is the number of times that rcu_try_flip_idle() decided
+	to start a new grace period.  "i1" should be roughly equal to
+	"ie1" plus "g1".
+
+o	"a1" is the number of calls to rcu_try_flip_waitack().
+
+o	"ae1" is the number of times that rcu_try_flip_waitack() found
+	that at least one CPU had not yet acknowledge the new grace period
+	(AKA "counter flip").
+
+o	"a2" is the number of time rcu_try_flip_waitack() found that
+	all CPUs had acknowledged.  "a1" should be roughly equal to
+	"ae1" plus "a2".  (This particular output was collected on
+	a 128-CPU machine, hence the smaller-than-usual fraction of
+	calls to rcu_try_flip_waitack() finding all CPUs having already
+	acknowledged.)
+
+o	"z1" is the number of calls to rcu_try_flip_waitzero().
+
+o	"ze1" is the number of times that rcu_try_flip_waitzero() found
+	that not all of the old RCU read-side critical sections had
+	completed.
+
+o	"z2" is the number of times that rcu_try_flip_waitzero() finds
+	the sum of the counters equal to zero, in other words, that
+	all of the old RCU read-side critical sections had completed.
+	The value of "z1" should be roughly equal to "ze1" plus
+	"z2".
+
+o	"m1" is the number of calls to rcu_try_flip_waitmb().
+
+o	"me1" is the number of times that rcu_try_flip_waitmb() finds
+	that at least one CPU has not yet executed a memory barrier.
+
+o	"m2" is the number of times that rcu_try_flip_waitmb() finds that
+	all CPUs have executed a memory barrier.
+
+
+Hierarchical RCU debugfs Files and Formats
+
+This implementation of RCU provides three debugfs files under the
+top-level directory RCU: rcu/rcudata (which displays fields in struct
+rcu_data), rcu/rcugp (which displays grace-period counters), and
+rcu/rcuhier (which displays the struct rcu_node hierarchy).
+
+The output of "cat rcu/rcudata" looks as follows:
+
+rcu:
+  0 c=4011 g=4012 pq=1 pqc=4011 qp=0 rpfq=1 rp=3c2a dt=23301/73 dn=2 df=1882 of=0 ri=2126 ql=2 b=10
+  1 c=4011 g=4012 pq=1 pqc=4011 qp=0 rpfq=3 rp=39a6 dt=78073/1 dn=2 df=1402 of=0 ri=1875 ql=46 b=10
+  2 c=4010 g=4010 pq=1 pqc=4010 qp=0 rpfq=-5 rp=1d12 dt=16646/0 dn=2 df=3140 of=0 ri=2080 ql=0 b=10
+  3 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=2b50 dt=21159/1 dn=2 df=2230 of=0 ri=1923 ql=72 b=10
+  4 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=1644 dt=5783/1 dn=2 df=3348 of=0 ri=2805 ql=7 b=10
+  5 c=4012 g=4013 pq=0 pqc=4011 qp=1 rpfq=3 rp=1aac dt=5879/1 dn=2 df=3140 of=0 ri=2066 ql=10 b=10
+  6 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=ed8 dt=5847/1 dn=2 df=3797 of=0 ri=1266 ql=10 b=10
+  7 c=4012 g=4013 pq=1 pqc=4012 qp=1 rpfq=3 rp=1fa2 dt=6199/1 dn=2 df=2795 of=0 ri=2162 ql=28 b=10
+rcu_bh:
+  0 c=-268 g=-268 pq=1 pqc=-268 qp=0 rpfq=-145 rp=21d6 dt=23301/73 dn=2 df=0 of=0 ri=0 ql=0 b=10
+  1 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-170 rp=20ce dt=78073/1 dn=2 df=26 of=0 ri=5 ql=0 b=10
+  2 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-83 rp=fbd dt=16646/0 dn=2 df=28 of=0 ri=4 ql=0 b=10
+  3 c=-268 g=-268 pq=1 pqc=-268 qp=0 rpfq=-105 rp=178c dt=21159/1 dn=2 df=28 of=0 ri=2 ql=0 b=10
+  4 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-30 rp=b54 dt=5783/1 dn=2 df=32 of=0 ri=0 ql=0 b=10
+  5 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-29 rp=df5 dt=5879/1 dn=2 df=30 of=0 ri=3 ql=0 b=10
+  6 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-28 rp=788 dt=5847/1 dn=2 df=32 of=0 ri=0 ql=0 b=10
+  7 c=-268 g=-268 pq=1 pqc=-268 qp=1 rpfq=-53 rp=1098 dt=6199/1 dn=2 df=30 of=0 ri=3 ql=0 b=10
+
+The first section lists the rcu_data structures for rcu, the second for
+rcu_bh.  Each section has one line per CPU, or eight for this 8-CPU system.
+The fields are as follows:
+
+o	The number at the beginning of each line is the CPU number.
+	CPUs numbers followed by an exclamation mark are offline,
+	but have been online at least once since boot.	There will be
+	no output for CPUs that have never been online, which can be
+	a good thing in the surprisingly common case where NR_CPUS is
+	substantially larger than the number of actual CPUs.
+
+o	"c" is the count of grace periods that this CPU believes have
+	completed.  CPUs in dynticks idle mode may lag quite a ways
+	behind, for example, CPU 4 under "rcu" above, which has slept
+	through the past 25 RCU grace periods.	It is not unusual to
+	see CPUs lagging by thousands of grace periods.
+
+o	"g" is the count of grace periods that this CPU believes have
+	started.  Again, CPUs in dynticks idle mode may lag behind.
+	If the "c" and "g" values are equal, this CPU has already
+	reported a quiescent state for the last RCU grace period that
+	it is aware of, otherwise, the CPU believes that it owes RCU a
+	quiescent state.
+
+o	"pq" indicates that this CPU has passed through a quiescent state
+	for the current grace period.  It is possible for "pq" to be
+	"1" and "c" different than "g", which indicates that although
+	the CPU has passed through a quiescent state, either (1) this
+	CPU has not yet reported that fact, (2) some other CPU has not
+	yet reported for this grace period, or (3) both.
+
+o	"pqc" indicates which grace period the last-observed quiescent
+	state for this CPU corresponds to.  This is important for handling
+	the race between CPU 0 reporting an extended dynticks-idle
+	quiescent state for CPU 1 and CPU 1 suddenly waking up and
+	reporting its own quiescent state.  If CPU 1 was the last CPU
+	for the current grace period, then the CPU that loses this race
+	will attempt to incorrectly mark CPU 1 as having checked in for
+	the next grace period!
+
+o	"qp" indicates that RCU still expects a quiescent state from
+	this CPU.
+
+o	"rpfq" is the number of rcu_pending() calls on this CPU required
+	to induce this CPU to invoke force_quiescent_state().
+
+o	"rp" is low-order four hex digits of the count of how many times
+	rcu_pending() has been invoked on this CPU.
+
+o	"dt" is the current value of the dyntick counter that is incremented
+	when entering or leaving dynticks idle state, either by the
+	scheduler or by irq.  The number after the "/" is the interrupt
+	nesting depth when in dyntick-idle state, or one greater than
+	the interrupt-nesting depth otherwise.
+
+	This field is displayed only for CONFIG_NO_HZ kernels.
+
+o	"dn" is the current value of the dyntick counter that is incremented
+	when entering or leaving dynticks idle state via NMI.  If both
+	the "dt" and "dn" values are even, then this CPU is in dynticks
+	idle mode and may be ignored by RCU.  If either of these two
+	counters is odd, then RCU must be alert to the possibility of
+	an RCU read-side critical section running on this CPU.
+
+	This field is displayed only for CONFIG_NO_HZ kernels.
+
+o	"df" is the number of times that some other CPU has forced a
+	quiescent state on behalf of this CPU due to this CPU being in
+	dynticks-idle state.
+
+	This field is displayed only for CONFIG_NO_HZ kernels.
+
+o	"of" is the number of times that some other CPU has forced a
+	quiescent state on behalf of this CPU due to this CPU being
+	offline.  In a perfect world, this might neve happen, but it
+	turns out that offlining and onlining a CPU can take several grace
+	periods, and so there is likely to be an extended period of time
+	when RCU believes that the CPU is online when it really is not.
+	Please note that erring in the other direction (RCU believing a
+	CPU is offline when it is really alive and kicking) is a fatal
+	error, so it makes sense to err conservatively.
+
+o	"ri" is the number of times that RCU has seen fit to send a
+	reschedule IPI to this CPU in order to get it to report a
+	quiescent state.
+
+o	"ql" is the number of RCU callbacks currently residing on
+	this CPU.  This is the total number of callbacks, regardless
+	of what state they are in (new, waiting for grace period to
+	start, waiting for grace period to end, ready to invoke).
+
+o	"b" is the batch limit for this CPU.  If more than this number
+	of RCU callbacks is ready to invoke, then the remainder will
+	be deferred.
+
+
+The output of "cat rcu/rcugp" looks as follows:
+
+rcu: completed=33062  gpnum=33063
+rcu_bh: completed=464  gpnum=464
+
+Again, this output is for both "rcu" and "rcu_bh".  The fields are
+taken from the rcu_state structure, and are as follows:
+
+o	"completed" is the number of grace periods that have completed.
+	It is comparable to the "c" field from rcu/rcudata in that a
+	CPU whose "c" field matches the value of "completed" is aware
+	that the corresponding RCU grace period has completed.
+
+o	"gpnum" is the number of grace periods that have started.  It is
+	comparable to the "g" field from rcu/rcudata in that a CPU
+	whose "g" field matches the value of "gpnum" is aware that the
+	corresponding RCU grace period has started.
+
+	If these two fields are equal (as they are for "rcu_bh" above),
+	then there is no grace period in progress, in other words, RCU
+	is idle.  On the other hand, if the two fields differ (as they
+	do for "rcu" above), then an RCU grace period is in progress.
+
+
+The output of "cat rcu/rcuhier" looks as follows, with very long lines:
+
+c=6902 g=6903 s=2 jfq=3 j=72c7 nfqs=13142/nfqsng=0(13142) fqlh=6
+1/1 0:127 ^0    
+3/3 0:35 ^0    0/0 36:71 ^1    0/0 72:107 ^2    0/0 108:127 ^3    
+3/3f 0:5 ^0    2/3 6:11 ^1    0/0 12:17 ^2    0/0 18:23 ^3    0/0 24:29 ^4    0/0 30:35 ^5    0/0 36:41 ^0    0/0 42:47 ^1    0/0 48:53 ^2    0/0 54:59 ^3    0/0 60:65 ^4    0/0 66:71 ^5    0/0 72:77 ^0    0/0 78:83 ^1    0/0 84:89 ^2    0/0 90:95 ^3    0/0 96:101 ^4    0/0 102:107 ^5    0/0 108:113 ^0    0/0 114:119 ^1    0/0 120:125 ^2    0/0 126:127 ^3    
+rcu_bh:
+c=-226 g=-226 s=1 jfq=-5701 j=72c7 nfqs=88/nfqsng=0(88) fqlh=0
+0/1 0:127 ^0    
+0/3 0:35 ^0    0/0 36:71 ^1    0/0 72:107 ^2    0/0 108:127 ^3    
+0/3f 0:5 ^0    0/3 6:11 ^1    0/0 12:17 ^2    0/0 18:23 ^3    0/0 24:29 ^4    0/0 30:35 ^5    0/0 36:41 ^0    0/0 42:47 ^1    0/0 48:53 ^2    0/0 54:59 ^3    0/0 60:65 ^4    0/0 66:71 ^5    0/0 72:77 ^0    0/0 78:83 ^1    0/0 84:89 ^2    0/0 90:95 ^3    0/0 96:101 ^4    0/0 102:107 ^5    0/0 108:113 ^0    0/0 114:119 ^1    0/0 120:125 ^2    0/0 126:127 ^3
+
+This is once again split into "rcu" and "rcu_bh" portions.  The fields are
+as follows:
+
+o	"c" is exactly the same as "completed" under rcu/rcugp.
+
+o	"g" is exactly the same as "gpnum" under rcu/rcugp.
+
+o	"s" is the "signaled" state that drives force_quiescent_state()'s
+	state machine.
+
+o	"jfq" is the number of jiffies remaining for this grace period
+	before force_quiescent_state() is invoked to help push things
+	along.  Note that CPUs in dyntick-idle mode thoughout the grace
+	period will not report on their own, but rather must be check by
+	some other CPU via force_quiescent_state().
+
+o	"j" is the low-order four hex digits of the jiffies counter.
+	Yes, Paul did run into a number of problems that turned out to
+	be due to the jiffies counter no longer counting.  Why do you ask?
+
+o	"nfqs" is the number of calls to force_quiescent_state() since
+	boot.
+
+o	"nfqsng" is the number of useless calls to force_quiescent_state(),
+	where there wasn't actually a grace period active.  This can
+	happen due to races.  The number in parentheses is the difference
+	between "nfqs" and "nfqsng", or the number of times that
+	force_quiescent_state() actually did some real work.
+
+o	"fqlh" is the number of calls to force_quiescent_state() that
+	exited immediately (without even being counted in nfqs above)
+	due to contention on ->fqslock.
+
+o	Each element of the form "1/1 0:127 ^0" represents one struct
+	rcu_node.  Each line represents one level of the hierarchy, from
+	root to leaves.  It is best to think of the rcu_data structures
+	as forming yet another level after the leaves.  Note that there
+	might be either one, two, or three levels of rcu_node structures,
+	depending on the relationship between CONFIG_RCU_FANOUT and
+	CONFIG_NR_CPUS.
+	
+	o	The numbers separated by the "/" are the qsmask followed
+		by the qsmaskinit.  The qsmask will have one bit
+		set for each entity in the next lower level that
+		has not yet checked in for the current grace period.
+		The qsmaskinit will have one bit for each entity that is
+		currently expected to check in during each grace period.
+		The value of qsmaskinit is assigned to that of qsmask
+		at the beginning of each grace period.
+
+		For example, for "rcu", the qsmask of the first entry
+		of the lowest level is 0x14, meaning that we are still
+		waiting for CPUs 2 and 4 to check in for the current
+		grace period.
+
+	o	The numbers separated by the ":" are the range of CPUs
+		served by this struct rcu_node.  This can be helpful
+		in working out how the hierarchy is wired together.
+
+		For example, the first entry at the lowest level shows
+		"0:5", indicating that it covers CPUs 0 through 5.
+
+	o	The number after the "^" indicates the bit in the
+		next higher level rcu_node structure that this
+		rcu_node structure corresponds to.
+
+		For example, the first entry at the lowest level shows
+		"^0", indicating that it corresponds to bit zero in
+		the first entry at the middle level.

Documentation/SAK.txt

@@ -1,5 +1,5 @@
 Linux 2.4.2 Secure Attention Key (SAK) handling
-18 March 2001, Andrew Morton <akpm@osdl.org>
+18 March 2001, Andrew Morton
 
 An operating system's Secure Attention Key is a security tool which is
 provided as protection against trojan password capturing programs.  It

Documentation/SubmitChecklist

@@ -85,3 +85,6 @@ kernel patches.
 23: Tested after it has been merged into the -mm patchset to make sure
     that it still works with all of the other queued patches and various
     changes in the VM, VFS, and other subsystems.
+
+24: All memory barriers {e.g., barrier(), rmb(), wmb()} need a comment in the
+    source code that explains the logic of what they are doing and why.

Documentation/SubmittingDrivers

@@ -41,7 +41,7 @@ Linux 2.4:
 Linux 2.6:
 	The same rules apply as 2.4 except that you should follow linux-kernel
 	to track changes in API's. The final contact point for Linux 2.6
-	submissions is Andrew Morton <akpm@osdl.org>.
+	submissions is Andrew Morton.
 
 What Criteria Determine Acceptance
 ----------------------------------

Documentation/SubmittingPatches

@@ -77,7 +77,7 @@ Quilt:
 http://savannah.nongnu.org/projects/quilt
 
 Andrew Morton's patch scripts:
-http://www.zip.com.au/~akpm/linux/patches/
+http://userweb.kernel.org/~akpm/stuff/patch-scripts.tar.gz
 Instead of these scripts, quilt is the recommended patch management
 tool (see above).
 
@@ -405,7 +405,7 @@ person it names.  This tag documents that potentially interested parties
 have been included in the discussion
 
 
-14) Using Test-by: and Reviewed-by:
+14) Using Tested-by: and Reviewed-by:
 
 A Tested-by: tag indicates that the patch has been successfully tested (in
 some environment) by the person named.  This tag informs maintainers that
@@ -653,7 +653,7 @@ SECTION 3 - REFERENCES
 ----------------------
 
 Andrew Morton, "The perfect patch" (tpp).
-  <http://www.zip.com.au/~akpm/linux/patches/stuff/tpp.txt>
+  <http://userweb.kernel.org/~akpm/stuff/tpp.txt>
 
 Jeff Garzik, "Linux kernel patch submission format".
   <http://linux.yyz.us/patch-format.html>
@@ -672,4 +672,9 @@ Kernel Documentation/CodingStyle:
 
 Linus Torvalds's mail on the canonical patch format:
   <http://lkml.org/lkml/2005/4/7/183>
+
+Andi Kleen, "On submitting kernel patches"
+  Some strategies to get difficult or controversal changes in.
+  http://halobates.de/on-submitting-patches.pdf
+
 --

Documentation/accounting/.gitignore

@@ -0,0 +1 @@
+getdelays

Documentation/acpi/debug.txt

@@ -0,0 +1,148 @@
+			ACPI Debug Output
+
+
+The ACPI CA, the Linux ACPI core, and some ACPI drivers can generate debug
+output.  This document describes how to use this facility.
+
+Compile-time configuration
+--------------------------
+
+ACPI debug output is globally enabled by CONFIG_ACPI_DEBUG.  If this config
+option is turned off, the debug messages are not even built into the
+kernel.
+
+Boot- and run-time configuration
+--------------------------------
+
+When CONFIG_ACPI_DEBUG=y, you can select the component and level of messages
+you're interested in.  At boot-time, use the acpi.debug_layer and
+acpi.debug_level kernel command line options.  After boot, you can use the
+debug_layer and debug_level files in /sys/module/acpi/parameters/ to control
+the debug messages.
+
+debug_layer (component)
+-----------------------
+
+The "debug_layer" is a mask that selects components of interest, e.g., a
+specific driver or part of the ACPI interpreter.  To build the debug_layer
+bitmask, look for the "#define _COMPONENT" in an ACPI source file.
+
+You can set the debug_layer mask at boot-time using the acpi.debug_layer
+command line argument, and you can change it after boot by writing values
+to /sys/module/acpi/parameters/debug_layer.
+
+The possible components are defined in include/acpi/acoutput.h and
+include/acpi/acpi_drivers.h.  Reading /sys/module/acpi/parameters/debug_layer
+shows the supported mask values, currently these:
+
+    ACPI_UTILITIES                  0x00000001
+    ACPI_HARDWARE                   0x00000002
+    ACPI_EVENTS                     0x00000004
+    ACPI_TABLES                     0x00000008
+    ACPI_NAMESPACE                  0x00000010
+    ACPI_PARSER                     0x00000020
+    ACPI_DISPATCHER                 0x00000040
+    ACPI_EXECUTER                   0x00000080
+    ACPI_RESOURCES                  0x00000100
+    ACPI_CA_DEBUGGER                0x00000200
+    ACPI_OS_SERVICES                0x00000400
+    ACPI_CA_DISASSEMBLER            0x00000800
+    ACPI_COMPILER                   0x00001000
+    ACPI_TOOLS                      0x00002000
+    ACPI_BUS_COMPONENT              0x00010000
+    ACPI_AC_COMPONENT               0x00020000
+    ACPI_BATTERY_COMPONENT          0x00040000
+    ACPI_BUTTON_COMPONENT           0x00080000
+    ACPI_SBS_COMPONENT              0x00100000
+    ACPI_FAN_COMPONENT              0x00200000
+    ACPI_PCI_COMPONENT              0x00400000
+    ACPI_POWER_COMPONENT            0x00800000
+    ACPI_CONTAINER_COMPONENT        0x01000000
+    ACPI_SYSTEM_COMPONENT           0x02000000
+    ACPI_THERMAL_COMPONENT          0x04000000
+    ACPI_MEMORY_DEVICE_COMPONENT    0x08000000
+    ACPI_VIDEO_COMPONENT            0x10000000
+    ACPI_PROCESSOR_COMPONENT        0x20000000
+
+debug_level
+-----------
+
+The "debug_level" is a mask that selects different types of messages, e.g.,
+those related to initialization, method execution, informational messages, etc.
+To build debug_level, look at the level specified in an ACPI_DEBUG_PRINT()
+statement.
+
+The ACPI interpreter uses several different levels, but the Linux
+ACPI core and ACPI drivers generally only use ACPI_LV_INFO.
+
+You can set the debug_level mask at boot-time using the acpi.debug_level
+command line argument, and you can change it after boot by writing values
+to /sys/module/acpi/parameters/debug_level.
+
+The possible levels are defined in include/acpi/acoutput.h.  Reading
+/sys/module/acpi/parameters/debug_level shows the supported mask values,
+currently these:
+
+    ACPI_LV_INIT                    0x00000001
+    ACPI_LV_DEBUG_OBJECT            0x00000002
+    ACPI_LV_INFO                    0x00000004
+    ACPI_LV_INIT_NAMES              0x00000020
+    ACPI_LV_PARSE                   0x00000040
+    ACPI_LV_LOAD                    0x00000080
+    ACPI_LV_DISPATCH                0x00000100
+    ACPI_LV_EXEC                    0x00000200
+    ACPI_LV_NAMES                   0x00000400
+    ACPI_LV_OPREGION                0x00000800
+    ACPI_LV_BFIELD                  0x00001000
+    ACPI_LV_TABLES                  0x00002000
+    ACPI_LV_VALUES                  0x00004000
+    ACPI_LV_OBJECTS                 0x00008000
+    ACPI_LV_RESOURCES               0x00010000
+    ACPI_LV_USER_REQUESTS           0x00020000
+    ACPI_LV_PACKAGE                 0x00040000
+    ACPI_LV_ALLOCATIONS             0x00100000
+    ACPI_LV_FUNCTIONS               0x00200000
+    ACPI_LV_OPTIMIZATIONS           0x00400000
+    ACPI_LV_MUTEX                   0x01000000
+    ACPI_LV_THREADS                 0x02000000
+    ACPI_LV_IO                      0x04000000
+    ACPI_LV_INTERRUPTS              0x08000000
+    ACPI_LV_AML_DISASSEMBLE         0x10000000
+    ACPI_LV_VERBOSE_INFO            0x20000000
+    ACPI_LV_FULL_TABLES             0x40000000
+    ACPI_LV_EVENTS                  0x80000000
+
+Examples
+--------
+
+For example, drivers/acpi/bus.c contains this:
+
+    #define _COMPONENT              ACPI_BUS_COMPONENT
+    ...
+    ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Device insertion detected\n"));
+
+To turn on this message, set the ACPI_BUS_COMPONENT bit in acpi.debug_layer
+and the ACPI_LV_INFO bit in acpi.debug_level.  (The ACPI_DEBUG_PRINT
+statement uses ACPI_DB_INFO, which is macro based on the ACPI_LV_INFO
+definition.)
+
+Enable all AML "Debug" output (stores to the Debug object while interpreting
+AML) during boot:
+
+    acpi.debug_layer=0xffffffff acpi.debug_level=0x2
+
+Enable PCI and PCI interrupt routing debug messages:
+
+    acpi.debug_layer=0x400000 acpi.debug_level=0x4
+
+Enable all ACPI hardware-related messages:
+
+    acpi.debug_layer=0x2 acpi.debug_level=0xffffffff
+
+Enable all ACPI_DB_INFO messages after boot:
+
+    # echo 0x4 > /sys/module/acpi/parameters/debug_level
+
+Show all valid component values:
+
+    # cat /sys/module/acpi/parameters/debug_layer

Documentation/arm/empeg/README

@@ -1,13 +0,0 @@
-Empeg, Ltd's Empeg MP3 Car Audio Player
-
-The initial design is to go in your car, but you can use it at home, on a
-boat... almost anywhere. The principle is to store CD-quality music using
-MPEG technology onto a hard disk in the unit, and use the power of the
-embedded computer to serve up the music you want.
-
-For more details, see:
-
-	http://www.empeg.com
-
-
-

Documentation/arm/empeg/ir.txt

@@ -1,49 +0,0 @@
-Infra-red driver documentation.
-
-Mike Crowe <mac@empeg.com>
-(C) Empeg Ltd 1999
-
-Not a lot here yet :-)
-
-The Kenwood KCA-R6A remote control generates a sequence like the following:
-
-Go low for approx 16T (Around 9000us)
-Go high for approx 8T (Around 4000us)
-Go low for less than 2T (Around 750us)
-
-For each of the 32 bits
-  Go high for more than 2T (Around 1500us) == 1
-  Go high for less than T (Around 400us) == 0
-  Go low for less than 2T (Around 750us)
-
-Rather than repeat a signal when the button is held down certain buttons
-generate the following code to indicate repetition.
-
-Go low for approx 16T
-Go high for approx 4T
-Go low for less than 2T
-
-(By removing the <2T from the start of the sequence and placing at the end
- it can be considered a stop bit but I found it easier to deal with it at
- the start).
-
-The 32 bits are encoded as XxYy where x and y are the actual data values
-while X and Y are the logical inverses of the associated data values. Using 
-LSB first yields sensible codes for the numbers.
-
-All codes are of the form b9xx
-
-The numeric keys generate the code 0x where x is the number pressed.
-
-Tuner		1c
-Tape		1d
-CD		1e
-CD-MD-CH	1f
-Track-		0a
-Track+		0b
-Rewind		0c
-FF		0d
-DNPP		5e
-Play/Pause	0e
-Vol+		14
-Vol-		15

Documentation/arm/empeg/mkdevs

@@ -1,11 +0,0 @@
-#!/bin/sh
-mknod /dev/display c 244 0
-mknod /dev/ir c 242 0
-mknod /dev/usb0 c 243 0
-mknod /dev/audio c 245 4
-mknod /dev/dsp c 245 3
-mknod /dev/mixer c 245 0
-mknod /dev/empeg_state c 246 0
-mknod /dev/radio0 c 81 64
-ln -sf radio0 radio
-ln -sf usb0 usb

Documentation/arm/mem_alignment

@@ -24,7 +24,7 @@ real bad - it changes the behaviour of all unaligned instructions in user
 space, and might cause programs to fail unexpectedly.
 
 To change the alignment trap behavior, simply echo a number into
-/proc/sys/debug/alignment.  The number is made up from various bits:
+/proc/cpu/alignment.  The number is made up from various bits:
 
 bit		behavior when set
 ---		-----------------

Documentation/arm/pxa/mfp.txt

@@ -0,0 +1,286 @@
+                 MFP Configuration for PXA2xx/PXA3xx Processors
+
+			Eric Miao <eric.miao@marvell.com>
+
+MFP stands for Multi-Function Pin, which is the pin-mux logic on PXA3xx and
+later PXA series processors.  This document describes the existing MFP API,
+and how board/platform driver authors could make use of it.
+
+ Basic Concept
+===============
+
+Unlike the GPIO alternate function settings on PXA25x and PXA27x, a new MFP
+mechanism is introduced from PXA3xx to completely move the pin-mux functions
+out of the GPIO controller. In addition to pin-mux configurations, the MFP
+also controls the low power state, driving strength, pull-up/down and event
+detection of each pin.  Below is a diagram of internal connections between
+the MFP logic and the remaining SoC peripherals:
+
+ +--------+
+ |        |--(GPIO19)--+
+ |  GPIO  |            |
+ |        |--(GPIO...) |
+ +--------+            |
+                       |       +---------+
+ +--------+            +------>|         |
+ |  PWM2  |--(PWM_OUT)-------->|   MFP   |
+ +--------+            +------>|         |-------> to external PAD
+                       | +---->|         |
+ +--------+            | | +-->|         |
+ |  SSP2  |---(TXD)----+ | |   +---------+
+ +--------+              | |
+                         | |
+ +--------+              | |
+ | Keypad |--(MKOUT4)----+ |
+ +--------+                |
+                           |
+ +--------+                |
+ |  UART2 |---(TXD)--------+
+ +--------+
+
+NOTE: the external pad is named as MFP_PIN_GPIO19, it doesn't necessarily
+mean it's dedicated for GPIO19, only as a hint that internally this pin
+can be routed from GPIO19 of the GPIO controller.
+
+To better understand the change from PXA25x/PXA27x GPIO alternate function
+to this new MFP mechanism, here are several key points:
+
+  1. GPIO controller on PXA3xx is now a dedicated controller, same as other
+     internal controllers like PWM, SSP and UART, with 128 internal signals
+     which can be routed to external through one or more MFPs (e.g. GPIO<0>
+     can be routed through either MFP_PIN_GPIO0 as well as MFP_PIN_GPIO0_2,
+     see arch/arm/mach-pxa/mach/include/mfp-pxa300.h)
+
+  2. Alternate function configuration is removed from this GPIO controller,
+     the remaining functions are pure GPIO-specific, i.e.
+
+       - GPIO signal level control
+       - GPIO direction control
+       - GPIO level change detection
+
+  3. Low power state for each pin is now controlled by MFP, this means the
+     PGSRx registers on PXA2xx are now useless on PXA3xx
+
+  4. Wakeup detection is now controlled by MFP, PWER does not control the
+     wakeup from GPIO(s) any more, depending on the sleeping state, ADxER
+     (as defined in pxa3xx-regs.h) controls the wakeup from MFP
+
+NOTE: with such a clear separation of MFP and GPIO, by GPIO<xx> we normally
+mean it is a GPIO signal, and by MFP<xxx> or pin xxx, we mean a physical
+pad (or ball).
+
+ MFP API Usage
+===============
+
+For board code writers, here are some guidelines:
+
+1. include ONE of the following header files in your <board>.c:
+
+   - #include <mach/mfp-pxa25x.h>
+   - #include <mach/mfp-pxa27x.h>
+   - #include <mach/mfp-pxa300.h>
+   - #include <mach/mfp-pxa320.h>
+   - #include <mach/mfp-pxa930.h>
+
+   NOTE: only one file in your <board>.c, depending on the processors used,
+   because pin configuration definitions may conflict in these file (i.e.
+   same name, different meaning and settings on different processors). E.g.
+   for zylonite platform, which support both PXA300/PXA310 and PXA320, two
+   separate files are introduced: zylonite_pxa300.c and zylonite_pxa320.c
+   (in addition to handle MFP configuration differences, they also handle
+   the other differences between the two combinations).
+
+   NOTE: PXA300 and PXA310 are almost identical in pin configurations (with
+   PXA310 supporting some additional ones), thus the difference is actually
+   covered in a single mfp-pxa300.h.
+
+2. prepare an array for the initial pin configurations, e.g.:
+
+   static unsigned long mainstone_pin_config[] __initdata = {
+	/* Chip Select */
+	GPIO15_nCS_1,
+
+	/* LCD - 16bpp Active TFT */
+	GPIOxx_TFT_LCD_16BPP,
+	GPIO16_PWM0_OUT,	/* Backlight */
+
+	/* MMC */
+	GPIO32_MMC_CLK,
+	GPIO112_MMC_CMD,
+	GPIO92_MMC_DAT_0,
+	GPIO109_MMC_DAT_1,
+	GPIO110_MMC_DAT_2,
+	GPIO111_MMC_DAT_3,
+
+	...
+
+	/* GPIO */
+	GPIO1_GPIO | WAKEUP_ON_EDGE_BOTH,
+   };
+
+   a) once the pin configurations are passed to pxa{2xx,3xx}_mfp_config(),
+   and written to the actual registers, they are useless and may discard,
+   adding '__initdata' will help save some additional bytes here.
+
+   b) when there is only one possible pin configurations for a component,
+   some simplified definitions can be used, e.g. GPIOxx_TFT_LCD_16BPP on
+   PXA25x and PXA27x processors
+
+   c) if by board design, a pin can be configured to wake up the system
+   from low power state, it can be 'OR'ed with any of:
+
+      WAKEUP_ON_EDGE_BOTH
+      WAKEUP_ON_EDGE_RISE
+      WAKEUP_ON_EDGE_FALL
+      WAKEUP_ON_LEVEL_HIGH - specifically for enabling of keypad GPIOs,
+
+   to indicate that this pin has the capability of wake-up the system,
+   and on which edge(s). This, however, doesn't necessarily mean the
+   pin _will_ wakeup the system, it will only when set_irq_wake() is
+   invoked with the corresponding GPIO IRQ (GPIO_IRQ(xx) or gpio_to_irq())
+   and eventually calls gpio_set_wake() for the actual register setting.
+
+   d) although PXA3xx MFP supports edge detection on each pin, the
+   internal logic will only wakeup the system when those specific bits
+   in ADxER registers are set, which can be well mapped to the
+   corresponding peripheral, thus set_irq_wake() can be called with 
+   the peripheral IRQ to enable the wakeup.
+
+
+ MFP on PXA3xx
+===============
+
+Every external I/O pad on PXA3xx (excluding those for special purpose) has
+one MFP logic associated, and is controlled by one MFP register (MFPR).
+
+The MFPR has the following bit definitions (for PXA300/PXA310/PXA320):
+
+ 31                        16 15 14 13 12 11 10  9  8  7  6  5  4  3  2  1  0
+  +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+  |         RESERVED        |PS|PU|PD|  DRIVE |SS|SD|SO|EC|EF|ER|--| AF_SEL |
+  +-------------------------+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
+
+  Bit 3:   RESERVED
+  Bit 4:   EDGE_RISE_EN - enable detection of rising edge on this pin
+  Bit 5:   EDGE_FALL_EN - enable detection of falling edge on this pin
+  Bit 6:   EDGE_CLEAR   - disable edge detection on this pin
+  Bit 7:   SLEEP_OE_N   - enable outputs during low power modes
+  Bit 8:   SLEEP_DATA   - output data on the pin during low power modes
+  Bit 9:   SLEEP_SEL    - selection control for low power modes signals
+  Bit 13:  PULLDOWN_EN  - enable the internal pull-down resistor on this pin
+  Bit 14:  PULLUP_EN    - enable the internal pull-up resistor on this pin
+  Bit 15:  PULL_SEL     - pull state controlled by selected alternate function
+                          (0) or by PULL{UP,DOWN}_EN bits (1)
+
+  Bit 0 - 2: AF_SEL - alternate function selection, 8 possibilities, from 0-7
+  Bit 10-12: DRIVE  - drive strength and slew rate
+			0b000 - fast 1mA
+			0b001 - fast 2mA
+			0b002 - fast 3mA
+			0b003 - fast 4mA
+			0b004 - slow 6mA
+			0b005 - fast 6mA
+			0b006 - slow 10mA
+			0b007 - fast 10mA
+
+ MFP Design for PXA2xx/PXA3xx
+==============================
+
+Due to the difference of pin-mux handling between PXA2xx and PXA3xx, a unified
+MFP API is introduced to cover both series of processors.
+
+The basic idea of this design is to introduce definitions for all possible pin
+configurations, these definitions are processor and platform independent, and
+the actual API invoked to convert these definitions into register settings and
+make them effective there-after.
+
+  Files Involved
+  --------------
+
+  - arch/arm/mach-pxa/include/mach/mfp.h
+  
+  for
+    1. Unified pin definitions - enum constants for all configurable pins
+    2. processor-neutral bit definitions for a possible MFP configuration
+
+  - arch/arm/mach-pxa/include/mach/mfp-pxa3xx.h
+
+  for PXA3xx specific MFPR register bit definitions and PXA3xx common pin
+  configurations
+
+  - arch/arm/mach-pxa/include/mach/mfp-pxa2xx.h
+
+  for PXA2xx specific definitions and PXA25x/PXA27x common pin configurations
+
+  - arch/arm/mach-pxa/include/mach/mfp-pxa25x.h
+    arch/arm/mach-pxa/include/mach/mfp-pxa27x.h
+    arch/arm/mach-pxa/include/mach/mfp-pxa300.h
+    arch/arm/mach-pxa/include/mach/mfp-pxa320.h
+    arch/arm/mach-pxa/include/mach/mfp-pxa930.h
+
+  for processor specific definitions
+
+  - arch/arm/mach-pxa/mfp-pxa3xx.c
+  - arch/arm/mach-pxa/mfp-pxa2xx.c
+
+  for implementation of the pin configuration to take effect for the actual
+  processor.
+
+  Pin Configuration
+  -----------------
+
+  The following comments are copied from mfp.h (see the actual source code
+  for most updated info)
+  
+  /*
+   * a possible MFP configuration is represented by a 32-bit integer
+   *
+   * bit  0.. 9 - MFP Pin Number (1024 Pins Maximum)
+   * bit 10..12 - Alternate Function Selection
+   * bit 13..15 - Drive Strength
+   * bit 16..18 - Low Power Mode State
+   * bit 19..20 - Low Power Mode Edge Detection
+   * bit 21..22 - Run Mode Pull State
+   *
+   * to facilitate the definition, the following macros are provided
+   *
+   * MFP_CFG_DEFAULT - default MFP configuration value, with
+   * 		  alternate function = 0,
+   * 		  drive strength = fast 3mA (MFP_DS03X)
+   * 		  low power mode = default
+   * 		  edge detection = none
+   *
+   * MFP_CFG	- default MFPR value with alternate function
+   * MFP_CFG_DRV	- default MFPR value with alternate function and
+   * 		  pin drive strength
+   * MFP_CFG_LPM	- default MFPR value with alternate function and
+   * 		  low power mode
+   * MFP_CFG_X	- default MFPR value with alternate function,
+   * 		  pin drive strength and low power mode
+   */
+
+   Examples of pin configurations are:
+
+   #define GPIO94_SSP3_RXD		MFP_CFG_X(GPIO94, AF1, DS08X, FLOAT)
+
+   which reads GPIO94 can be configured as SSP3_RXD, with alternate function
+   selection of 1, driving strength of 0b101, and a float state in low power
+   modes.
+
+   NOTE: this is the default setting of this pin being configured as SSP3_RXD
+   which can be modified a bit in board code, though it is not recommended to
+   do so, simply because this default setting is usually carefully encoded,
+   and is supposed to work in most cases.
+
+  Register Settings
+  -----------------
+
+   Register settings on PXA3xx for a pin configuration is actually very
+   straight-forward, most bits can be converted directly into MFPR value
+   in a easier way. Two sets of MFPR values are calculated: the run-time
+   ones and the low power mode ones, to allow different settings.
+
+   The conversion from a generic pin configuration to the actual register
+   settings on PXA2xx is a bit complicated: many registers are involved,
+   including GAFRx, GPDRx, PGSRx, PWER, PKWR, PFER and PRER. Please see
+   mfp-pxa2xx.c for how the conversion is made.

Documentation/auxdisplay/.gitignore

@@ -0,0 +1 @@
+cfag12864b-example

Documentation/block/biodoc.txt

@@ -914,7 +914,7 @@ I/O scheduler, a.k.a. elevator, is implemented in two layers.  Generic dispatch
 queue and specific I/O schedulers.  Unless stated otherwise, elevator is used
 to refer to both parts and I/O scheduler to specific I/O schedulers.
 
-Block layer implements generic dispatch queue in ll_rw_blk.c and elevator.c.
+Block layer implements generic dispatch queue in block/*.c.
 The generic dispatch queue is responsible for properly ordering barrier
 requests, requeueing, handling non-fs requests and all other subtleties.
 
@@ -926,8 +926,8 @@ be built inside the kernel.  Each queue can choose different one and can also
 change to another one dynamically.
 
 A block layer call to the i/o scheduler follows the convention elv_xxx(). This
-calls elevator_xxx_fn in the elevator switch (drivers/block/elevator.c). Oh,
-xxx and xxx might not match exactly, but use your imagination. If an elevator
+calls elevator_xxx_fn in the elevator switch (block/elevator.c). Oh, xxx
+and xxx might not match exactly, but use your imagination. If an elevator
 doesn't implement a function, the switch does nothing or some minimal house
 keeping work.
 

Documentation/block/data-integrity.txt

@@ -246,7 +246,7 @@ will require extra work due to the application tag.
       retrieve the tag buffer using bio_integrity_get_tag().
 
 
-6.3 PASSING EXISTING INTEGRITY METADATA
+5.3 PASSING EXISTING INTEGRITY METADATA
 
     Filesystems that either generate their own integrity metadata or
     are capable of transferring IMD from user space can use the
@@ -283,7 +283,7 @@ will require extra work due to the application tag.
       integrity upon completion.
 
 
-6.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
+5.4 REGISTERING A BLOCK DEVICE AS CAPABLE OF EXCHANGING INTEGRITY
     METADATA
 
     To enable integrity exchange on a block device the gendisk must be

Documentation/blockdev/00-INDEX

@@ -0,0 +1,16 @@
+00-INDEX
+	- this file
+README.DAC960
+	- info on Mylex DAC960/DAC1100 PCI RAID Controller Driver for Linux.
+cciss.txt
+	- info, major/minor #'s for Compaq's SMART Array Controllers.
+cpqarray.txt
+	- info on using Compaq's SMART2 Intelligent Disk Array Controllers.
+floppy.txt
+	- notes and driver options for the floppy disk driver.
+nbd.txt
+	- info on a TCP implementation of a network block device.
+paride.txt
+	- information about the parallel port IDE subsystem.
+ramdisk.txt
+	- short guide on how to set up and use the RAM disk.

Documentation/blockdev/cciss.txt

@@ -0,0 +1,171 @@
+This driver is for Compaq's SMART Array Controllers.
+
+Supported Cards:
+----------------
+
+This driver is known to work with the following cards:
+
+	* SA 5300
+	* SA 5i 
+	* SA 532
+	* SA 5312
+	* SA 641
+	* SA 642
+	* SA 6400
+	* SA 6400 U320 Expansion Module
+	* SA 6i
+	* SA P600
+	* SA P800
+	* SA E400
+	* SA P400i
+	* SA E200
+	* SA E200i
+	* SA E500
+	* SA P700m
+	* SA P212
+	* SA P410
+	* SA P410i
+	* SA P411
+	* SA P812
+	* SA P712m
+	* SA P711m
+
+Detecting drive failures:
+-------------------------
+
+To get the status of logical volumes and to detect physical drive
+failures, you can use the cciss_vol_status program found here:
+http://cciss.sourceforge.net/#cciss_utils
+
+Device Naming:
+--------------
+
+If nodes are not already created in the /dev/cciss directory, run as root:
+
+# cd /dev
+# ./MAKEDEV cciss
+
+You need some entries in /dev for the cciss device.  The MAKEDEV script
+can make device nodes for you automatically.  Currently the device setup
+is as follows:
+
+Major numbers:
+	104	cciss0	
+	105	cciss1	
+	106	cciss2
+	105	cciss3
+	108	cciss4
+	109	cciss5
+	110	cciss6
+	111	cciss7
+
+Minor numbers:
+        b7 b6 b5 b4 b3 b2 b1 b0
+        |----+----| |----+----|
+             |           |
+             |           +-------- Partition ID (0=wholedev, 1-15 partition)
+             |
+             +-------------------- Logical Volume number
+
+The device naming scheme is:
+/dev/cciss/c0d0			Controller 0, disk 0, whole device
+/dev/cciss/c0d0p1		Controller 0, disk 0, partition 1
+/dev/cciss/c0d0p2		Controller 0, disk 0, partition 2
+/dev/cciss/c0d0p3		Controller 0, disk 0, partition 3
+
+/dev/cciss/c1d1			Controller 1, disk 1, whole device
+/dev/cciss/c1d1p1		Controller 1, disk 1, partition 1
+/dev/cciss/c1d1p2		Controller 1, disk 1, partition 2
+/dev/cciss/c1d1p3		Controller 1, disk 1, partition 3
+
+SCSI tape drive and medium changer support
+------------------------------------------
+
+SCSI sequential access devices and medium changer devices are supported and 
+appropriate device nodes are automatically created.  (e.g.  
+/dev/st0, /dev/st1, etc.  See the "st" man page for more details.) 
+You must enable "SCSI tape drive support for Smart Array 5xxx" and 
+"SCSI support" in your kernel configuration to be able to use SCSI
+tape drives with your Smart Array 5xxx controller.
+
+Additionally, note that the driver will not engage the SCSI core at init 
+time.  The driver must be directed to dynamically engage the SCSI core via 
+the /proc filesystem entry which the "block" side of the driver creates as 
+/proc/driver/cciss/cciss* at runtime.  This is because at driver init time, 
+the SCSI core may not yet be initialized (because the driver is a block 
+driver) and attempting to register it with the SCSI core in such a case 
+would cause a hang.  This is best done via an initialization script 
+(typically in /etc/init.d, but could vary depending on distribution). 
+For example:
+
+	for x in /proc/driver/cciss/cciss[0-9]*
+	do
+		echo "engage scsi" > $x
+	done
+
+Once the SCSI core is engaged by the driver, it cannot be disengaged 
+(except by unloading the driver, if it happens to be linked as a module.)
+
+Note also that if no sequential access devices or medium changers are
+detected, the SCSI core will not be engaged by the action of the above
+script.
+
+Hot plug support for SCSI tape drives
+-------------------------------------
+
+Hot plugging of SCSI tape drives is supported, with some caveats.
+The cciss driver must be informed that changes to the SCSI bus
+have been made.  This may be done via the /proc filesystem.
+For example:
+
+	echo "rescan" > /proc/scsi/cciss0/1
+
+This causes the driver to query the adapter about changes to the
+physical SCSI buses and/or fibre channel arbitrated loop and the
+driver to make note of any new or removed sequential access devices
+or medium changers.  The driver will output messages indicating what 
+devices have been added or removed and the controller, bus, target and 
+lun used to address the device.  It then notifies the SCSI mid layer
+of these changes.
+
+Note that the naming convention of the /proc filesystem entries 
+contains a number in addition to the driver name.  (E.g. "cciss0" 
+instead of just "cciss" which you might expect.)
+
+Note: ONLY sequential access devices and medium changers are presented 
+as SCSI devices to the SCSI mid layer by the cciss driver.  Specifically, 
+physical SCSI disk drives are NOT presented to the SCSI mid layer.  The 
+physical SCSI disk drives are controlled directly by the array controller 
+hardware and it is important to prevent the kernel from attempting to directly
+access these devices too, as if the array controller were merely a SCSI 
+controller in the same way that we are allowing it to access SCSI tape drives.
+
+SCSI error handling for tape drives and medium changers
+-------------------------------------------------------
+
+The linux SCSI mid layer provides an error handling protocol which
+kicks into gear whenever a SCSI command fails to complete within a
+certain amount of time (which can vary depending on the command).
+The cciss driver participates in this protocol to some extent.  The
+normal protocol is a four step process.  First the device is told
+to abort the command.  If that doesn't work, the device is reset.
+If that doesn't work, the SCSI bus is reset.  If that doesn't work
+the host bus adapter is reset.  Because the cciss driver is a block
+driver as well as a SCSI driver and only the tape drives and medium
+changers are presented to the SCSI mid layer, and unlike more 
+straightforward SCSI drivers, disk i/o continues through the block
+side during the SCSI error recovery process, the cciss driver only
+implements the first two of these actions, aborting the command, and
+resetting the device.  Additionally, most tape drives will not oblige 
+in aborting commands, and sometimes it appears they will not even 
+obey a reset command, though in most circumstances they will.  In
+the case that the command cannot be aborted and the device cannot be 
+reset, the device will be set offline.
+
+In the event the error handling code is triggered and a tape drive is
+successfully reset or the tardy command is successfully aborted, the 
+tape drive may still not allow i/o to continue until some command
+is issued which positions the tape to a known position.  Typically you
+must rewind the tape (by issuing "mt -f /dev/st0 rewind" for example)
+before i/o can proceed again to a tape drive which was reset.
+

Documentation/c2port.txt

@@ -0,0 +1,90 @@
+			C2 port support
+			---------------
+
+(C) Copyright 2007 Rodolfo Giometti <giometti@enneenne.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+
+
+Overview
+--------
+
+This driver implements the support for Linux of Silicon Labs (Silabs)
+C2 Interface used for in-system programming of micro controllers.
+
+By using this driver you can reprogram the in-system flash without EC2
+or EC3 debug adapter. This solution is also useful in those systems
+where the micro controller is connected via special GPIOs pins.
+
+References
+----------
+
+The C2 Interface main references are at (http://www.silabs.com)
+Silicon Laboratories site], see:
+
+- AN127: FLASH Programming via the C2 Interface at
+http://www.silabs.com/public/documents/tpub_doc/anote/Microcontrollers/Small_Form_Factor/en/an127.pdf, and
+
+- C2 Specification at
+http://www.silabs.com/public/documents/tpub_doc/spec/Microcontrollers/en/C2spec.pdf,
+
+however it implements a two wire serial communication protocol (bit
+banging) designed to enable in-system programming, debugging, and
+boundary-scan testing on low pin-count Silicon Labs devices. Currently
+this code supports only flash programming but extensions are easy to
+add.
+
+Using the driver
+----------------
+
+Once the driver is loaded you can use sysfs support to get C2port's
+info or read/write in-system flash.
+
+# ls /sys/class/c2port/c2port0/
+access            flash_block_size  flash_erase       rev_id
+dev_id            flash_blocks_num  flash_size        subsystem/
+flash_access      flash_data        reset             uevent
+
+Initially the C2port access is disabled since you hardware may have
+such lines multiplexed with other devices so, to get access to the
+C2port, you need the command:
+
+# echo 1 > /sys/class/c2port/c2port0/access
+
+after that you should read the device ID and revision ID of the
+connected micro controller:
+
+# cat /sys/class/c2port/c2port0/dev_id
+8
+# cat /sys/class/c2port/c2port0/rev_id
+1
+
+However, for security reasons, the in-system flash access in not
+enabled yet, to do so you need the command:
+
+# echo 1 > /sys/class/c2port/c2port0/flash_access
+
+After that you can read the whole flash:
+
+# cat /sys/class/c2port/c2port0/flash_data > image
+
+erase it:
+
+# echo 1 > /sys/class/c2port/c2port0/flash_erase
+
+and write it:
+
+# cat image > /sys/class/c2port/c2port0/flash_data
+
+after writing you have to reset the device to execute the new code:
+
+# echo 1 > /sys/class/c2port/c2port0/reset

Documentation/cciss.txt

@@ -1,168 +0,0 @@
-This driver is for Compaq's SMART Array Controllers.
-
-Supported Cards:
-----------------
-
-This driver is known to work with the following cards:
-
-	* SA 5300
-	* SA 5i 
-	* SA 532
-	* SA 5312
-	* SA 641
-	* SA 642
-	* SA 6400
-	* SA 6400 U320 Expansion Module
-	* SA 6i
-	* SA P600
-	* SA P800
-	* SA E400
-	* SA P400i
-	* SA E200
-	* SA E200i
-	* SA E500
-	* SA P212
-	* SA P410
-	* SA P410i
-	* SA P411
-	* SA P812
-
-Detecting drive failures:
--------------------------
-
-To get the status of logical volumes and to detect physical drive
-failures, you can use the cciss_vol_status program found here:
-http://cciss.sourceforge.net/#cciss_utils
-
-Device Naming:
---------------
-
-If nodes are not already created in the /dev/cciss directory, run as root:
-
-# cd /dev
-# ./MAKEDEV cciss
-
-You need some entries in /dev for the cciss device.  The MAKEDEV script
-can make device nodes for you automatically.  Currently the device setup
-is as follows:
-
-Major numbers:
-	104	cciss0	
-	105	cciss1	
-	106	cciss2
-	105	cciss3
-	108	cciss4
-	109	cciss5
-	110	cciss6
-	111	cciss7
-
-Minor numbers:
-        b7 b6 b5 b4 b3 b2 b1 b0
-        |----+----| |----+----|
-             |           |
-             |           +-------- Partition ID (0=wholedev, 1-15 partition)
-             |
-             +-------------------- Logical Volume number
-
-The device naming scheme is:
-/dev/cciss/c0d0			Controller 0, disk 0, whole device
-/dev/cciss/c0d0p1		Controller 0, disk 0, partition 1
-/dev/cciss/c0d0p2		Controller 0, disk 0, partition 2
-/dev/cciss/c0d0p3		Controller 0, disk 0, partition 3
-
-/dev/cciss/c1d1			Controller 1, disk 1, whole device
-/dev/cciss/c1d1p1		Controller 1, disk 1, partition 1
-/dev/cciss/c1d1p2		Controller 1, disk 1, partition 2
-/dev/cciss/c1d1p3		Controller 1, disk 1, partition 3
-
-SCSI tape drive and medium changer support
-------------------------------------------
-
-SCSI sequential access devices and medium changer devices are supported and 
-appropriate device nodes are automatically created.  (e.g.  
-/dev/st0, /dev/st1, etc.  See the "st" man page for more details.) 
-You must enable "SCSI tape drive support for Smart Array 5xxx" and 
-"SCSI support" in your kernel configuration to be able to use SCSI
-tape drives with your Smart Array 5xxx controller.
-
-Additionally, note that the driver will not engage the SCSI core at init 
-time.  The driver must be directed to dynamically engage the SCSI core via 
-the /proc filesystem entry which the "block" side of the driver creates as 
-/proc/driver/cciss/cciss* at runtime.  This is because at driver init time, 
-the SCSI core may not yet be initialized (because the driver is a block 
-driver) and attempting to register it with the SCSI core in such a case 
-would cause a hang.  This is best done via an initialization script 
-(typically in /etc/init.d, but could vary depending on distribution). 
-For example:
-
-	for x in /proc/driver/cciss/cciss[0-9]*
-	do
-		echo "engage scsi" > $x
-	done
-
-Once the SCSI core is engaged by the driver, it cannot be disengaged 
-(except by unloading the driver, if it happens to be linked as a module.)
-
-Note also that if no sequential access devices or medium changers are
-detected, the SCSI core will not be engaged by the action of the above
-script.
-
-Hot plug support for SCSI tape drives
--------------------------------------
-
-Hot plugging of SCSI tape drives is supported, with some caveats.
-The cciss driver must be informed that changes to the SCSI bus
-have been made.  This may be done via the /proc filesystem.
-For example:
-
-	echo "rescan" > /proc/scsi/cciss0/1
-
-This causes the driver to query the adapter about changes to the
-physical SCSI buses and/or fibre channel arbitrated loop and the
-driver to make note of any new or removed sequential access devices
-or medium changers.  The driver will output messages indicating what 
-devices have been added or removed and the controller, bus, target and 
-lun used to address the device.  It then notifies the SCSI mid layer
-of these changes.
-
-Note that the naming convention of the /proc filesystem entries 
-contains a number in addition to the driver name.  (E.g. "cciss0" 
-instead of just "cciss" which you might expect.)
-
-Note: ONLY sequential access devices and medium changers are presented 
-as SCSI devices to the SCSI mid layer by the cciss driver.  Specifically, 
-physical SCSI disk drives are NOT presented to the SCSI mid layer.  The 
-physical SCSI disk drives are controlled directly by the array controller 
-hardware and it is important to prevent the kernel from attempting to directly
-access these devices too, as if the array controller were merely a SCSI 
-controller in the same way that we are allowing it to access SCSI tape drives.
-
-SCSI error handling for tape drives and medium changers
--------------------------------------------------------
-
-The linux SCSI mid layer provides an error handling protocol which
-kicks into gear whenever a SCSI command fails to complete within a
-certain amount of time (which can vary depending on the command).
-The cciss driver participates in this protocol to some extent.  The
-normal protocol is a four step process.  First the device is told
-to abort the command.  If that doesn't work, the device is reset.
-If that doesn't work, the SCSI bus is reset.  If that doesn't work
-the host bus adapter is reset.  Because the cciss driver is a block
-driver as well as a SCSI driver and only the tape drives and medium
-changers are presented to the SCSI mid layer, and unlike more 
-straightforward SCSI drivers, disk i/o continues through the block
-side during the SCSI error recovery process, the cciss driver only
-implements the first two of these actions, aborting the command, and
-resetting the device.  Additionally, most tape drives will not oblige 
-in aborting commands, and sometimes it appears they will not even 
-obey a reset command, though in most circumstances they will.  In
-the case that the command cannot be aborted and the device cannot be 
-reset, the device will be set offline.
-
-In the event the error handling code is triggered and a tape drive is
-successfully reset or the tardy command is successfully aborted, the 
-tape drive may still not allow i/o to continue until some command
-is issued which positions the tape to a known position.  Typically you
-must rewind the tape (by issuing "mt -f /dev/st0 rewind" for example)
-before i/o can proceed again to a tape drive which was reset.
-

Documentation/cgroups/freezer-subsystem.txt

@@ -0,0 +1,102 @@
+The cgroup freezer is useful to batch job management system which start
+and stop sets of tasks in order to schedule the resources of a machine
+according to the desires of a system administrator. This sort of program
+is often used on HPC clusters to schedule access to the cluster as a
+whole. The cgroup freezer uses cgroups to describe the set of tasks to
+be started/stopped by the batch job management system. It also provides
+a means to start and stop the tasks composing the job.
+
+The cgroup freezer will also be useful for checkpointing running groups
+of tasks. The freezer allows the checkpoint code to obtain a consistent
+image of the tasks by attempting to force the tasks in a cgroup into a
+quiescent state. Once the tasks are quiescent another task can
+walk /proc or invoke a kernel interface to gather information about the
+quiesced tasks. Checkpointed tasks can be restarted later should a
+recoverable error occur. This also allows the checkpointed tasks to be
+migrated between nodes in a cluster by copying the gathered information
+to another node and restarting the tasks there.
+
+Sequences of SIGSTOP and SIGCONT are not always sufficient for stopping
+and resuming tasks in userspace. Both of these signals are observable
+from within the tasks we wish to freeze. While SIGSTOP cannot be caught,
+blocked, or ignored it can be seen by waiting or ptracing parent tasks.
+SIGCONT is especially unsuitable since it can be caught by the task. Any
+programs designed to watch for SIGSTOP and SIGCONT could be broken by
+attempting to use SIGSTOP and SIGCONT to stop and resume tasks. We can
+demonstrate this problem using nested bash shells:
+
+	$ echo $$
+	16644
+	$ bash
+	$ echo $$
+	16690
+
+	From a second, unrelated bash shell:
+	$ kill -SIGSTOP 16690
+	$ kill -SIGCONT 16990
+
+	<at this point 16990 exits and causes 16644 to exit too>
+
+This happens because bash can observe both signals and choose how it
+responds to them.
+
+Another example of a program which catches and responds to these
+signals is gdb. In fact any program designed to use ptrace is likely to
+have a problem with this method of stopping and resuming tasks.
+
+In contrast, the cgroup freezer uses the kernel freezer code to
+prevent the freeze/unfreeze cycle from becoming visible to the tasks
+being frozen. This allows the bash example above and gdb to run as
+expected.
+
+The freezer subsystem in the container filesystem defines a file named
+freezer.state. Writing "FROZEN" to the state file will freeze all tasks in the
+cgroup. Subsequently writing "THAWED" will unfreeze the tasks in the cgroup.
+Reading will return the current state.
+
+Note freezer.state doesn't exist in root cgroup, which means root cgroup
+is non-freezable.
+
+* Examples of usage :
+
+   # mkdir /containers
+   # mount -t cgroup -ofreezer freezer  /containers
+   # mkdir /containers/0
+   # echo $some_pid > /containers/0/tasks
+
+to get status of the freezer subsystem :
+
+   # cat /containers/0/freezer.state
+   THAWED
+
+to freeze all tasks in the container :
+
+   # echo FROZEN > /containers/0/freezer.state
+   # cat /containers/0/freezer.state
+   FREEZING
+   # cat /containers/0/freezer.state
+   FROZEN
+
+to unfreeze all tasks in the container :
+
+   # echo THAWED > /containers/0/freezer.state
+   # cat /containers/0/freezer.state
+   THAWED
+
+This is the basic mechanism which should do the right thing for user space task
+in a simple scenario.
+
+It's important to note that freezing can be incomplete. In that case we return
+EBUSY. This means that some tasks in the cgroup are busy doing something that
+prevents us from completely freezing the cgroup at this time. After EBUSY,
+the cgroup will remain partially frozen -- reflected by freezer.state reporting
+"FREEZING" when read. The state will remain "FREEZING" until one of these
+things happens:
+
+	1) Userspace cancels the freezing operation by writing "THAWED" to
+		the freezer.state file
+	2) Userspace retries the freezing operation by writing "FROZEN" to
+		the freezer.state file (writing "FREEZING" is not legal
+		and returns EINVAL)
+	3) The tasks that blocked the cgroup from entering the "FROZEN"
+		state disappear from the cgroup's set of tasks.

Documentation/computone.txt

@@ -1,522 +0,0 @@
-NOTE: This is an unmaintained driver.  It is not guaranteed to work due to
-changes made in the tty layer in 2.6.  If you wish to take over maintenance of
-this driver, contact Michael Warfield <mhw@wittsend.com>.
-
-Changelog:
-----------
-11-01-2001:	Original Document
-
-10-29-2004:	Minor misspelling & format fix, update status of driver.
-		James Nelson <james4765@gmail.com>
-
-Computone Intelliport II/Plus Multiport Serial Driver
------------------------------------------------------
-
-Release Notes For Linux Kernel 2.2 and higher.
-These notes are for the drivers which have already been integrated into the
-kernel and have been tested on Linux kernels 2.0, 2.2, 2.3, and 2.4.
-
-Version: 1.2.14
-Date: 11/01/2001
-Historical Author: Andrew Manison <amanison@america.net>
-Primary Author: Doug McNash
-Support: support@computone.com
-Fixes and Updates: Mike Warfield <mhw@wittsend.com>
-
-This file assumes that you are using the Computone drivers which are
-integrated into the kernel sources.  For updating the drivers or installing
-drivers into kernels which do not already have Computone drivers, please
-refer to the instructions in the README.computone file in the driver patch.
-
-
-1. INTRODUCTION
-
-This driver supports the entire family of Intelliport II/Plus controllers
-with the exception of the MicroChannel controllers.  It does not support
-products previous to the Intelliport II.
-
-This driver was developed on the v2.0.x Linux tree and has been tested up
-to v2.4.14; it will probably not work with earlier v1.X kernels,.
-
-
-2. QUICK INSTALLATION
-
-Hardware - If you have an ISA card, find a free interrupt and io port. 
-		   List those in use with `cat /proc/interrupts` and 
-		   `cat /proc/ioports`.  Set the card dip switches to a free 
-		   address.  You may need to configure your BIOS to reserve an
-		   irq for an ISA card.  PCI and EISA parameters are set
-		   automagically.  Insert card into computer with the power off 
-		   before or after drivers installation.
-
-	Note the hardware address from the Computone ISA cards installed into
-		the system.  These are required for editing ip2.c or editing
-		/etc/modprobe.conf, or for specification on the modprobe
-		command line.
-
-	Note that the /etc/modules.conf should be used for older (pre-2.6)
-		kernels.
-
-Software -
-
-Module installation:
-
-a) Determine free irq/address to use if any (configure BIOS if need be)
-b) Run "make config" or "make menuconfig" or "make xconfig"
-   Select (m) module for CONFIG_COMPUTONE under character
-   devices.  CONFIG_PCI and CONFIG_MODULES also may need to be set.
-c) Set address on ISA cards then:
-   edit /usr/src/linux/drivers/char/ip2.c if needed 
-	or
-   edit /etc/modprobe.conf if needed (module).
-	or both to match this setting.
-d) Run "make modules"
-e) Run "make modules_install"
-f) Run "/sbin/depmod -a"
-g) install driver using `modprobe ip2 <options>` (options listed below)
-h) run ip2mkdev (either the script below or the binary version)
-
-
-Kernel installation:
-
-a) Determine free irq/address to use if any (configure BIOS if need be)
-b) Run "make config" or "make menuconfig" or "make xconfig"
-   Select (y) kernel for CONFIG_COMPUTONE under character
-   devices.  CONFIG_PCI may need to be set if you have PCI bus.
-c) Set address on ISA cards then:
-	   edit /usr/src/linux/drivers/char/ip2.c  
-           (Optional - may be specified on kernel command line now)
-d) Run "make zImage" or whatever target you prefer.
-e) mv /usr/src/linux/arch/i386/boot/zImage to /boot.
-f) Add new config for this kernel into /etc/lilo.conf, run "lilo"
-	or copy to a floppy disk and boot from that floppy disk.
-g) Reboot using this kernel
-h) run ip2mkdev (either the script below or the binary version)
-
-Kernel command line options:
-
-When compiling the driver into the kernel, io and irq may be
-compiled into the driver by editing ip2.c and setting the values for
-io and irq in the appropriate array.  An alternative is to specify
-a command line parameter to the kernel at boot up.
-
-        ip2=io0,irq0,io1,irq1,io2,irq2,io3,irq3
-
-Note that this order is very different from the specifications for the
-modload parameters which have separate IRQ and IO specifiers.
-
-The io port also selects PCI (1) and EISA (2) boards.
-
-        io=0    No board
-        io=1    PCI board
-        io=2    EISA board
-        else    ISA board io address
-
-You only need to specify the boards which are present.
-
-        Examples:
-
-                2 PCI boards:
-
-                        ip2=1,0,1,0
-
-                1 ISA board at 0x310 irq 5:
-
-                        ip2=0x310,5
-
-This can be added to and "append" option in lilo.conf similar to this:
-
-        append="ip2=1,0,1,0"
-
-
-3. INSTALLATION
-
-Previously, the driver sources were packaged with a set of patch files
-to update the character drivers' makefile and configuration file, and other 
-kernel source files. A build script (ip2build) was included which applies 
-the patches if needed, and build any utilities needed.
-What you receive may be a single patch file in conventional kernel
-patch format build script. That form can also be applied by
-running patch -p1 < ThePatchFile.  Otherwise run ip2build.
- 
-The driver can be installed as a module (recommended) or built into the 
-kernel. This is selected as for other drivers through the `make config`
-command from the root of the Linux source tree. If the driver is built 
-into the kernel you will need to edit the file ip2.c to match the boards 
-you are installing. See that file for instructions. If the driver is 
-installed as a module the configuration can also be specified on the
-modprobe command line as follows:
-
-	modprobe ip2 irq=irq1,irq2,irq3,irq4 io=addr1,addr2,addr3,addr4
-
-where irqnum is one of the valid Intelliport II interrupts (3,4,5,7,10,11,
-12,15) and addr1-4 are the base addresses for up to four controllers. If 
-the irqs are not specified the driver uses the default in ip2.c (which 
-selects polled mode). If no base addresses are specified the defaults in 
-ip2.c are used. If you are autoloading the driver module with kerneld or
-kmod the base addresses and interrupt number must also be set in ip2.c
-and recompile or just insert and options line in /etc/modprobe.conf or both.
-The options line is equivalent to the command line and takes precedence over
-what is in ip2.c. 
-
-/etc/modprobe.conf sample:
-	options ip2 io=1,0x328 irq=1,10
-	alias char-major-71 ip2
-	alias char-major-72 ip2
-	alias char-major-73 ip2
-
-The equivalent in ip2.c:
-
-static int io[IP2_MAX_BOARDS]= { 1, 0x328, 0, 0 };
-static int irq[IP2_MAX_BOARDS] = { 1, 10, -1, -1 }; 
-
-The equivalent for the kernel command line (in lilo.conf):
-
-        append="ip2=1,1,0x328,10"
-
-
-Note:	Both io and irq should be updated to reflect YOUR system.  An "io"
-	address of 1 or 2 indicates a PCI or EISA card in the board table.
-	The PCI or EISA irq will be assigned automatically.
-
-Specifying an invalid or in-use irq will default the driver into
-running in polled mode for that card.  If all irq entries are 0 then
-all cards will operate in polled mode.
-
-If you select the driver as part of the kernel run :
-
-	make zlilo (or whatever you do to create a bootable kernel)
-
-If you selected a module run :
-
-	make modules && make modules_install
-
-The utility ip2mkdev (see 5 and 7 below) creates all the device nodes
-required by the driver.  For a device to be created it must be configured
-in the driver and the board must be installed. Only devices corresponding
-to real IntelliPort II ports are created. With multiple boards and expansion
-boxes this will leave gaps in the sequence of device names. ip2mkdev uses
-Linux tty naming conventions: ttyF0 - ttyF255 for normal devices, and
-cuf0 - cuf255 for callout devices.
-
-
-4. USING THE DRIVERS
-
-As noted above, the driver implements the ports in accordance with Linux
-conventions, and the devices should be interchangeable with the standard
-serial devices. (This is a key point for problem reporting: please make
-sure that what you are trying do works on the ttySx/cuax ports first; then 
-tell us what went wrong with the ip2 ports!)
-
-Higher speeds can be obtained using the setserial utility which remaps 
-38,400 bps (extb) to 57,600 bps, 115,200 bps, or a custom speed. 
-Intelliport II installations using the PowerPort expansion module can
-use the custom speed setting to select the highest speeds: 153,600 bps,
-230,400 bps, 307,200 bps, 460,800bps and 921,600 bps. The base for
-custom baud rate configuration is fixed at 921,600 for cards/expansion
-modules with ST654's and 115200 for those with Cirrus CD1400's.  This
-corresponds to the maximum bit rates those chips are capable.  
-For example if the baud base is 921600 and the baud divisor is 18 then
-the custom rate is 921600/18 = 51200 bps.  See the setserial man page for
-complete details. Of course if stty accepts the higher rates now you can
-use that as well as the standard ioctls().
-
-
-5. ip2mkdev and assorted utilities...
-
-Several utilities, including the source for a binary ip2mkdev utility are
-available under .../drivers/char/ip2.  These can be build by changing to
-that directory and typing "make" after the kernel has be built.  If you do
-not wish to compile the binary utilities, the shell script below can be
-cut out and run as "ip2mkdev" to create the necessary device files.  To
-use the ip2mkdev script, you must have procfs enabled and the proc file
-system mounted on /proc.
-
-
-6. NOTES
-
-This is a release version of the driver, but it is impossible to test it
-in all configurations of Linux. If there is any anomalous behaviour that 
-does not match the standard serial port's behaviour please let us know.
-
-
-7. ip2mkdev shell script
-
-Previously, this script was simply attached here.  It is now attached as a
-shar archive to make it easier to extract the script from the documentation.
-To create the ip2mkdev shell script change to a convenient directory (/tmp
-works just fine) and run the following command:
-
-	unshar Documentation/computone.txt
-		(This file)
-
-You should now have a file ip2mkdev in your current working directory with
-permissions set to execute.  Running that script with then create the
-necessary devices for the Computone boards, interfaces, and ports which
-are present on you system at the time it is run.
-
-
-#!/bin/sh
-# This is a shell archive (produced by GNU sharutils 4.2.1).
-# To extract the files from this archive, save it to some FILE, remove
-# everything before the `!/bin/sh' line above, then type `sh FILE'.
-#
-# Made on 2001-10-29 10:32 EST by <mhw@alcove.wittsend.com>.
-# Source directory was `/home2/src/tmp'.
-#
-# Existing files will *not* be overwritten unless `-c' is specified.
-#
-# This shar contains:
-# length mode       name
-# ------ ---------- ------------------------------------------
-#   4251 -rwxr-xr-x ip2mkdev
-#
-save_IFS="${IFS}"
-IFS="${IFS}:"
-gettext_dir=FAILED
-locale_dir=FAILED
-first_param="$1"
-for dir in $PATH
-do
-  if test "$gettext_dir" = FAILED && test -f $dir/gettext \
-     && ($dir/gettext --version >/dev/null 2>&1)
-  then
-    set `$dir/gettext --version 2>&1`
-    if test "$3" = GNU
-    then
-      gettext_dir=$dir
-    fi
-  fi
-  if test "$locale_dir" = FAILED && test -f $dir/shar \
-     && ($dir/shar --print-text-domain-dir >/dev/null 2>&1)
-  then
-    locale_dir=`$dir/shar --print-text-domain-dir`
-  fi
-done
-IFS="$save_IFS"
-if test "$locale_dir" = FAILED || test "$gettext_dir" = FAILED
-then
-  echo=echo
-else
-  TEXTDOMAINDIR=$locale_dir
-  export TEXTDOMAINDIR
-  TEXTDOMAIN=sharutils
-  export TEXTDOMAIN
-  echo="$gettext_dir/gettext -s"
-fi
-if touch -am -t 200112312359.59 $$.touch >/dev/null 2>&1 && test ! -f 200112312359.59 -a -f $$.touch; then
-  shar_touch='touch -am -t $1$2$3$4$5$6.$7 "$8"'
-elif touch -am 123123592001.59 $$.touch >/dev/null 2>&1 && test ! -f 123123592001.59 -a ! -f 123123592001.5 -a -f $$.touch; then
-  shar_touch='touch -am $3$4$5$6$1$2.$7 "$8"'
-elif touch -am 1231235901 $$.touch >/dev/null 2>&1 && test ! -f 1231235901 -a -f $$.touch; then
-  shar_touch='touch -am $3$4$5$6$2 "$8"'
-else
-  shar_touch=:
-  echo
-  $echo 'WARNING: not restoring timestamps.  Consider getting and'
-  $echo "installing GNU \`touch', distributed in GNU File Utilities..."
-  echo
-fi
-rm -f 200112312359.59 123123592001.59 123123592001.5 1231235901 $$.touch
-#
-if mkdir _sh17581; then
-  $echo 'x -' 'creating lock directory'
-else
-  $echo 'failed to create lock directory'
-  exit 1
-fi
-# ============= ip2mkdev ==============
-if test -f 'ip2mkdev' && test "$first_param" != -c; then
-  $echo 'x -' SKIPPING 'ip2mkdev' '(file already exists)'
-else
-  $echo 'x -' extracting 'ip2mkdev' '(text)'
-  sed 's/^X//' << 'SHAR_EOF' > 'ip2mkdev' &&
-#!/bin/sh -
-#
-#	ip2mkdev
-#
-#	Make or remove devices as needed for Computone Intelliport drivers
-#
-#	First rule!  If the dev file exists and you need it, don't mess
-#	with it.  That prevents us from screwing up open ttys, ownership
-#	and permissions on a running system!
-#
-#	This script will NOT remove devices that no longer exist if their
-#	board or interface box has been removed.  If you want to get rid
-#	of them, you can manually do an "rm -f /dev/ttyF* /dev/cuaf*"
-#	before running this script.  Running this script will then recreate
-#	all the valid devices.
-#
-#	Michael H. Warfield
-#	/\/\|=mhw=|\/\/
-#	mhw@wittsend.com
-#
-#	Updated 10/29/2000 for version 1.2.13 naming convention
-#		under devfs.	/\/\|=mhw=|\/\/
-#
-#	Updated 03/09/2000 for devfs support in ip2 drivers. /\/\|=mhw=|\/\/
-#
-X
-if test -d /dev/ip2 ; then
-#	This is devfs mode...  We don't do anything except create symlinks
-#	from the real devices to the old names!
-X	cd /dev
-X	echo "Creating symbolic links to devfs devices"
-X	for i in `ls ip2` ; do
-X		if test ! -L ip2$i ; then
-X			# Remove it incase it wasn't a symlink (old device)
-X			rm -f ip2$i
-X			ln -s ip2/$i ip2$i
-X		fi
-X	done
-X	for i in `( cd tts ; ls F* )` ; do
-X		if test ! -L tty$i ; then
-X			# Remove it incase it wasn't a symlink (old device)
-X			rm -f tty$i
-X			ln -s tts/$i tty$i
-X		fi
-X	done
-X	for i in `( cd cua ; ls F* )` ; do
-X		DEVNUMBER=`expr $i : 'F\(.*\)'`
-X		if test ! -L cuf$DEVNUMBER ; then
-X			# Remove it incase it wasn't a symlink (old device)
-X			rm -f cuf$DEVNUMBER
-X			ln -s cua/$i cuf$DEVNUMBER
-X		fi
-X	done
-X	exit 0
-fi
-X
-if test ! -f /proc/tty/drivers
-then
-X	echo "\
-Unable to check driver status.
-Make sure proc file system is mounted."
-X
-X	exit 255
-fi
-X
-if test ! -f /proc/tty/driver/ip2
-then
-X	echo "\
-Unable to locate ip2 proc file.
-Attempting to load driver"
-X
-X	if /sbin/insmod ip2
-X	then
-X		if test ! -f /proc/tty/driver/ip2
-X		then
-X			echo "\
-Unable to locate ip2 proc file after loading driver.
-Driver initialization failure or driver version error.
-"
-X		exit 255
-X		fi
-X	else
-X		echo "Unable to load ip2 driver."
-X		exit 255
-X	fi
-fi
-X
-# Ok...  So we got the driver loaded and we can locate the procfs files.
-# Next we need our major numbers.
-X
-TTYMAJOR=`sed -e '/^ip2/!d' -e '/\/dev\/tt/!d' -e 's/.*tt[^ 	]*[ 	]*\([0-9]*\)[ 	]*.*/\1/' < /proc/tty/drivers`
-CUAMAJOR=`sed -e '/^ip2/!d' -e '/\/dev\/cu/!d' -e 's/.*cu[^ 	]*[ 	]*\([0-9]*\)[ 	]*.*/\1/' < /proc/tty/drivers`
-BRDMAJOR=`sed -e '/^Driver: /!d' -e 's/.*IMajor=\([0-9]*\)[ 	]*.*/\1/' < /proc/tty/driver/ip2`
-X
-echo "\
-TTYMAJOR = $TTYMAJOR
-CUAMAJOR = $CUAMAJOR
-BRDMAJOR = $BRDMAJOR
-"
-X
-# Ok...  Now we should know our major numbers, if appropriate...
-# Now we need our boards and start the device loops.
-X
-grep '^Board [0-9]:' /proc/tty/driver/ip2 | while read token number type alltherest
-do
-X	# The test for blank "type" will catch the stats lead-in lines
-X	# if they exist in the file
-X	if test "$type" = "vacant" -o "$type" = "Vacant" -o "$type" = ""
-X	then
-X		continue
-X	fi
-X
-X	BOARDNO=`expr "$number" : '\([0-9]\):'`
-X	PORTS=`expr "$alltherest" : '.*ports=\([0-9]*\)' | tr ',' ' '`
-X	MINORS=`expr "$alltherest" : '.*minors=\([0-9,]*\)' | tr ',' ' '`
-X
-X	if test "$BOARDNO" = "" -o "$PORTS" = ""
-X	then
-#	This may be a bug.  We should at least get this much information
-X		echo "Unable to process board line"
-X		continue
-X	fi
-X
-X	if test "$MINORS" = ""
-X	then
-#	Silently skip this one.  This board seems to have no boxes
-X		continue
-X	fi
-X
-X	echo "board $BOARDNO: $type ports = $PORTS; port numbers = $MINORS"
-X
-X	if test "$BRDMAJOR" != ""
-X	then
-X		BRDMINOR=`expr $BOARDNO \* 4`
-X		STSMINOR=`expr $BRDMINOR + 1`
-X		if test ! -c /dev/ip2ipl$BOARDNO ; then
-X			mknod /dev/ip2ipl$BOARDNO c $BRDMAJOR $BRDMINOR
-X		fi
-X		if test ! -c /dev/ip2stat$BOARDNO ; then
-X			mknod /dev/ip2stat$BOARDNO c $BRDMAJOR $STSMINOR
-X		fi
-X	fi
-X
-X	if test "$TTYMAJOR" != ""
-X	then
-X		PORTNO=$BOARDBASE
-X
-X		for PORTNO in $MINORS
-X		do
-X			if test ! -c /dev/ttyF$PORTNO ; then
-X				# We got the hardware but no device - make it
-X				mknod /dev/ttyF$PORTNO c $TTYMAJOR $PORTNO
-X			fi	
-X		done
-X	fi
-X
-X	if test "$CUAMAJOR" != ""
-X	then
-X		PORTNO=$BOARDBASE
-X
-X		for PORTNO in $MINORS
-X		do
-X			if test ! -c /dev/cuf$PORTNO ; then
-X				# We got the hardware but no device - make it
-X				mknod /dev/cuf$PORTNO c $CUAMAJOR $PORTNO
-X			fi	
-X		done
-X	fi
-done
-X
-Xexit 0
-SHAR_EOF
-  (set 20 01 10 29 10 32 01 'ip2mkdev'; eval "$shar_touch") &&
-  chmod 0755 'ip2mkdev' ||
-  $echo 'restore of' 'ip2mkdev' 'failed'
-  if ( md5sum --help 2>&1 | grep 'sage: md5sum \[' ) >/dev/null 2>&1 \
-  && ( md5sum --version 2>&1 | grep -v 'textutils 1.12' ) >/dev/null; then
-    md5sum -c << SHAR_EOF >/dev/null 2>&1 \
-    || $echo 'ip2mkdev:' 'MD5 check failed'
-cb5717134509f38bad9fde6b1f79b4a4  ip2mkdev
-SHAR_EOF
-  else
-    shar_count="`LC_ALL= LC_CTYPE= LANG= wc -c < 'ip2mkdev'`"
-    test 4251 -eq "$shar_count" ||
-    $echo 'ip2mkdev:' 'original size' '4251,' 'current size' "$shar_count!"
-  fi
-fi
-rm -fr _sh17581
-exit 0

Documentation/connector/.gitignore

@@ -0,0 +1 @@
+ucon

Documentation/controllers/cpuacct.txt

@@ -0,0 +1,32 @@
+CPU Accounting Controller
+-------------------------
+
+The CPU accounting controller is used to group tasks using cgroups and
+account the CPU usage of these groups of tasks.
+
+The CPU accounting controller supports multi-hierarchy groups. An accounting
+group accumulates the CPU usage of all of its child groups and the tasks
+directly present in its group.
+
+Accounting groups can be created by first mounting the cgroup filesystem.
+
+# mkdir /cgroups
+# mount -t cgroup -ocpuacct none /cgroups
+
+With the above step, the initial or the parent accounting group
+becomes visible at /cgroups. At bootup, this group includes all the
+tasks in the system. /cgroups/tasks lists the tasks in this cgroup.
+/cgroups/cpuacct.usage gives the CPU time (in nanoseconds) obtained by
+this group which is essentially the CPU time obtained by all the tasks
+in the system.
+
+New accounting groups can be created under the parent group /cgroups.
+
+# cd /cgroups
+# mkdir g1
+# echo $$ > g1
+
+The above steps create a new group g1 and move the current shell
+process (bash) into it. CPU time consumed by this bash and its children
+can be obtained from g1/cpuacct.usage and the same is accumulated in
+/cgroups/cpuacct.usage also.

Documentation/controllers/memory.txt

@@ -112,14 +112,22 @@ the per cgroup LRU.
 
 2.2.1 Accounting details
 
-All mapped pages (RSS) and unmapped user pages (Page Cache) are accounted.
-RSS pages are accounted at the time of page_add_*_rmap() unless they've already
-been accounted for earlier. A file page will be accounted for as Page Cache;
-it's mapped into the page tables of a process, duplicate accounting is carefully
-avoided. Page Cache pages are accounted at the time of add_to_page_cache().
-The corresponding routines that remove a page from the page tables or removes
-a page from Page Cache is used to decrement the accounting counters of the
-cgroup.
+All mapped anon pages (RSS) and cache pages (Page Cache) are accounted.
+(some pages which never be reclaimable and will not be on global LRU
+ are not accounted. we just accounts pages under usual vm management.)
+
+RSS pages are accounted at page_fault unless they've already been accounted
+for earlier. A file page will be accounted for as Page Cache when it's
+inserted into inode (radix-tree). While it's mapped into the page tables of
+processes, duplicate accounting is carefully avoided.
+
+A RSS page is unaccounted when it's fully unmapped. A PageCache page is
+unaccounted when it's removed from radix-tree.
+
+At page migration, accounting information is kept.
+
+Note: we just account pages-on-lru because our purpose is to control amount
+of used pages. not-on-lru pages are tend to be out-of-control from vm view.
 
 2.3 Shared Page Accounting
 

Documentation/cpu-freq/user-guide.txt

@@ -23,6 +23,7 @@ Contents:
 1.3 sparc64
 1.4 ppc
 1.5 SuperH
+1.6 Blackfin
 
 2. "Policy" / "Governor"?
 2.1 Policy
@@ -92,10 +93,19 @@ Several "PowerBook" and "iBook2" notebooks are supported.
 1.5 SuperH
 ----------
 
-The following SuperH processors are supported by cpufreq:
+All SuperH processors supporting rate rounding through the clock
+framework are supported by cpufreq.
 
-SH-3
-SH-4
+1.6 Blackfin
+------------
+
+The following Blackfin processors are supported by cpufreq:
+
+BF522, BF523, BF524, BF525, BF526, BF527, Rev 0.1 or higher
+BF531, BF532, BF533, Rev 0.3 or higher
+BF534, BF536, BF537, Rev 0.2 or higher
+BF561, Rev 0.3 or higher
+BF542, BF544, BF547, BF548, BF549, Rev 0.1 or higher
 
 
 2. "Policy" / "Governor" ?

Documentation/cpusets.txt

@@ -48,7 +48,7 @@ hooks, beyond what is already present, required to manage dynamic
 job placement on large systems.
 
 Cpusets use the generic cgroup subsystem described in
-Documentation/cgroup.txt.
+Documentation/cgroups/cgroups.txt.
 
 Requests by a task, using the sched_setaffinity(2) system call to
 include CPUs in its CPU affinity mask, and using the mbind(2) and

Documentation/credentials.txt

@@ -0,0 +1,582 @@
+			     ====================
+			     CREDENTIALS IN LINUX
+			     ====================
+
+By: David Howells <dhowells@redhat.com>
+
+Contents:
+
+ (*) Overview.
+
+ (*) Types of credentials.
+
+ (*) File markings.
+
+ (*) Task credentials.
+
+     - Immutable credentials.
+     - Accessing task credentials.
+     - Accessing another task's credentials.
+     - Altering credentials.
+     - Managing credentials.
+
+ (*) Open file credentials.
+
+ (*) Overriding the VFS's use of credentials.
+
+
+========
+OVERVIEW
+========
+
+There are several parts to the security check performed by Linux when one
+object acts upon another:
+
+ (1) Objects.
+
+     Objects are things in the system that may be acted upon directly by
+     userspace programs.  Linux has a variety of actionable objects, including:
+
+	- Tasks
+	- Files/inodes
+	- Sockets
+	- Message queues
+	- Shared memory segments
+	- Semaphores
+	- Keys
+
+     As a part of the description of all these objects there is a set of
+     credentials.  What's in the set depends on the type of object.
+
+ (2) Object ownership.
+
+     Amongst the credentials of most objects, there will be a subset that
+     indicates the ownership of that object.  This is used for resource
+     accounting and limitation (disk quotas and task rlimits for example).
+
+     In a standard UNIX filesystem, for instance, this will be defined by the
+     UID marked on the inode.
+
+ (3) The objective context.
+
+     Also amongst the credentials of those objects, there will be a subset that
+     indicates the 'objective context' of that object.  This may or may not be
+     the same set as in (2) - in standard UNIX files, for instance, this is the
+     defined by the UID and the GID marked on the inode.
+
+     The objective context is used as part of the security calculation that is
+     carried out when an object is acted upon.
+
+ (4) Subjects.
+
+     A subject is an object that is acting upon another object.
+
+     Most of the objects in the system are inactive: they don't act on other
+     objects within the system.  Processes/tasks are the obvious exception:
+     they do stuff; they access and manipulate things.
+
+     Objects other than tasks may under some circumstances also be subjects.
+     For instance an open file may send SIGIO to a task using the UID and EUID
+     given to it by a task that called fcntl(F_SETOWN) upon it.  In this case,
+     the file struct will have a subjective context too.
+
+ (5) The subjective context.
+
+     A subject has an additional interpretation of its credentials.  A subset
+     of its credentials forms the 'subjective context'.  The subjective context
+     is used as part of the security calculation that is carried out when a
+     subject acts.
+
+     A Linux task, for example, has the FSUID, FSGID and the supplementary
+     group list for when it is acting upon a file - which are quite separate
+     from the real UID and GID that normally form the objective context of the
+     task.
+
+ (6) Actions.
+
+     Linux has a number of actions available that a subject may perform upon an
+     object.  The set of actions available depends on the nature of the subject
+     and the object.
+
+     Actions include reading, writing, creating and deleting files; forking or
+     signalling and tracing tasks.
+
+ (7) Rules, access control lists and security calculations.
+
+     When a subject acts upon an object, a security calculation is made.  This
+     involves taking the subjective context, the objective context and the
+     action, and searching one or more sets of rules to see whether the subject
+     is granted or denied permission to act in the desired manner on the
+     object, given those contexts.
+
+     There are two main sources of rules:
+
+     (a) Discretionary access control (DAC):
+
+	 Sometimes the object will include sets of rules as part of its
+	 description.  This is an 'Access Control List' or 'ACL'.  A Linux
+	 file may supply more than one ACL.
+
+	 A traditional UNIX file, for example, includes a permissions mask that
+	 is an abbreviated ACL with three fixed classes of subject ('user',
+	 'group' and 'other'), each of which may be granted certain privileges
+	 ('read', 'write' and 'execute' - whatever those map to for the object
+	 in question).  UNIX file permissions do not allow the arbitrary
+	 specification of subjects, however, and so are of limited use.
+
+	 A Linux file might also sport a POSIX ACL.  This is a list of rules
+	 that grants various permissions to arbitrary subjects.
+
+     (b) Mandatory access control (MAC):
+
+	 The system as a whole may have one or more sets of rules that get
+	 applied to all subjects and objects, regardless of their source.
+	 SELinux and Smack are examples of this.
+
+	 In the case of SELinux and Smack, each object is given a label as part
+	 of its credentials.  When an action is requested, they take the
+	 subject label, the object label and the action and look for a rule
+	 that says that this action is either granted or denied.
+
+
+====================
+TYPES OF CREDENTIALS
+====================
+
+The Linux kernel supports the following types of credentials:
+
+ (1) Traditional UNIX credentials.
+
+	Real User ID
+	Real Group ID
+
+     The UID and GID are carried by most, if not all, Linux objects, even if in
+     some cases it has to be invented (FAT or CIFS files for example, which are
+     derived from Windows).  These (mostly) define the objective context of
+     that object, with tasks being slightly different in some cases.
+
+	Effective, Saved and FS User ID
+	Effective, Saved and FS Group ID
+	Supplementary groups
+
+     These are additional credentials used by tasks only.  Usually, an
+     EUID/EGID/GROUPS will be used as the subjective context, and real UID/GID
+     will be used as the objective.  For tasks, it should be noted that this is
+     not always true.
+
+ (2) Capabilities.
+
+	Set of permitted capabilities
+	Set of inheritable capabilities
+	Set of effective capabilities
+	Capability bounding set
+
+     These are only carried by tasks.  They indicate superior capabilities
+     granted piecemeal to a task that an ordinary task wouldn't otherwise have.
+     These are manipulated implicitly by changes to the traditional UNIX
+     credentials, but can also be manipulated directly by the capset() system
+     call.
+
+     The permitted capabilities are those caps that the process might grant
+     itself to its effective or permitted sets through capset().  This
+     inheritable set might also be so constrained.
+
+     The effective capabilities are the ones that a task is actually allowed to
+     make use of itself.
+
+     The inheritable capabilities are the ones that may get passed across
+     execve().
+
+     The bounding set limits the capabilities that may be inherited across
+     execve(), especially when a binary is executed that will execute as UID 0.
+
+ (3) Secure management flags (securebits).
+
+     These are only carried by tasks.  These govern the way the above
+     credentials are manipulated and inherited over certain operations such as
+     execve().  They aren't used directly as objective or subjective
+     credentials.
+
+ (4) Keys and keyrings.
+
+     These are only carried by tasks.  They carry and cache security tokens
+     that don't fit into the other standard UNIX credentials.  They are for
+     making such things as network filesystem keys available to the file
+     accesses performed by processes, without the necessity of ordinary
+     programs having to know about security details involved.
+
+     Keyrings are a special type of key.  They carry sets of other keys and can
+     be searched for the desired key.  Each process may subscribe to a number
+     of keyrings:
+
+	Per-thread keying
+	Per-process keyring
+	Per-session keyring
+
+     When a process accesses a key, if not already present, it will normally be
+     cached on one of these keyrings for future accesses to find.
+
+     For more information on using keys, see Documentation/keys.txt.
+
+ (5) LSM
+
+     The Linux Security Module allows extra controls to be placed over the
+     operations that a task may do.  Currently Linux supports two main
+     alternate LSM options: SELinux and Smack.
+
+     Both work by labelling the objects in a system and then applying sets of
+     rules (policies) that say what operations a task with one label may do to
+     an object with another label.
+
+ (6) AF_KEY
+
+     This is a socket-based approach to credential management for networking
+     stacks [RFC 2367].  It isn't discussed by this document as it doesn't
+     interact directly with task and file credentials; rather it keeps system
+     level credentials.
+
+
+When a file is opened, part of the opening task's subjective context is
+recorded in the file struct created.  This allows operations using that file
+struct to use those credentials instead of the subjective context of the task
+that issued the operation.  An example of this would be a file opened on a
+network filesystem where the credentials of the opened file should be presented
+to the server, regardless of who is actually doing a read or a write upon it.
+
+
+=============
+FILE MARKINGS
+=============
+
+Files on disk or obtained over the network may have annotations that form the
+objective security context of that file.  Depending on the type of filesystem,
+this may include one or more of the following:
+
+ (*) UNIX UID, GID, mode;
+
+ (*) Windows user ID;
+
+ (*) Access control list;
+
+ (*) LSM security label;
+
+ (*) UNIX exec privilege escalation bits (SUID/SGID);
+
+ (*) File capabilities exec privilege escalation bits.
+
+These are compared to the task's subjective security context, and certain
+operations allowed or disallowed as a result.  In the case of execve(), the
+privilege escalation bits come into play, and may allow the resulting process
+extra privileges, based on the annotations on the executable file.
+
+
+================
+TASK CREDENTIALS
+================
+
+In Linux, all of a task's credentials are held in (uid, gid) or through
+(groups, keys, LSM security) a refcounted structure of type 'struct cred'.
+Each task points to its credentials by a pointer called 'cred' in its
+task_struct.
+
+Once a set of credentials has been prepared and committed, it may not be
+changed, barring the following exceptions:
+
+ (1) its reference count may be changed;
+
+ (2) the reference count on the group_info struct it points to may be changed;
+
+ (3) the reference count on the security data it points to may be changed;
+
+ (4) the reference count on any keyrings it points to may be changed;
+
+ (5) any keyrings it points to may be revoked, expired or have their security
+     attributes changed; and
+
+ (6) the contents of any keyrings to which it points may be changed (the whole
+     point of keyrings being a shared set of credentials, modifiable by anyone
+     with appropriate access).
+
+To alter anything in the cred struct, the copy-and-replace principle must be
+adhered to.  First take a copy, then alter the copy and then use RCU to change
+the task pointer to make it point to the new copy.  There are wrappers to aid
+with this (see below).
+
+A task may only alter its _own_ credentials; it is no longer permitted for a
+task to alter another's credentials.  This means the capset() system call is no
+longer permitted to take any PID other than the one of the current process.
+Also keyctl_instantiate() and keyctl_negate() functions no longer permit
+attachment to process-specific keyrings in the requesting process as the
+instantiating process may need to create them.
+
+
+IMMUTABLE CREDENTIALS
+---------------------
+
+Once a set of credentials has been made public (by calling commit_creds() for
+example), it must be considered immutable, barring two exceptions:
+
+ (1) The reference count may be altered.
+
+ (2) Whilst the keyring subscriptions of a set of credentials may not be
+     changed, the keyrings subscribed to may have their contents altered.
+
+To catch accidental credential alteration at compile time, struct task_struct
+has _const_ pointers to its credential sets, as does struct file.  Furthermore,
+certain functions such as get_cred() and put_cred() operate on const pointers,
+thus rendering casts unnecessary, but require to temporarily ditch the const
+qualification to be able to alter the reference count.
+
+
+ACCESSING TASK CREDENTIALS
+--------------------------
+
+A task being able to alter only its own credentials permits the current process
+to read or replace its own credentials without the need for any form of locking
+- which simplifies things greatly.  It can just call:
+
+	const struct cred *current_cred()
+
+to get a pointer to its credentials structure, and it doesn't have to release
+it afterwards.
+
+There are convenience wrappers for retrieving specific aspects of a task's
+credentials (the value is simply returned in each case):
+
+	uid_t current_uid(void)		Current's real UID
+	gid_t current_gid(void)		Current's real GID
+	uid_t current_euid(void)	Current's effective UID
+	gid_t current_egid(void)	Current's effective GID
+	uid_t current_fsuid(void)	Current's file access UID
+	gid_t current_fsgid(void)	Current's file access GID
+	kernel_cap_t current_cap(void)	Current's effective capabilities
+	void *current_security(void)	Current's LSM security pointer
+	struct user_struct *current_user(void)  Current's user account
+
+There are also convenience wrappers for retrieving specific associated pairs of
+a task's credentials:
+
+	void current_uid_gid(uid_t *, gid_t *);
+	void current_euid_egid(uid_t *, gid_t *);
+	void current_fsuid_fsgid(uid_t *, gid_t *);
+
+which return these pairs of values through their arguments after retrieving
+them from the current task's credentials.
+
+
+In addition, there is a function for obtaining a reference on the current
+process's current set of credentials:
+
+	const struct cred *get_current_cred(void);
+
+and functions for getting references to one of the credentials that don't
+actually live in struct cred:
+
+	struct user_struct *get_current_user(void);
+	struct group_info *get_current_groups(void);
+
+which get references to the current process's user accounting structure and
+supplementary groups list respectively.
+
+Once a reference has been obtained, it must be released with put_cred(),
+free_uid() or put_group_info() as appropriate.
+
+
+ACCESSING ANOTHER TASK'S CREDENTIALS
+------------------------------------
+
+Whilst a task may access its own credentials without the need for locking, the
+same is not true of a task wanting to access another task's credentials.  It
+must use the RCU read lock and rcu_dereference().
+
+The rcu_dereference() is wrapped by:
+
+	const struct cred *__task_cred(struct task_struct *task);
+
+This should be used inside the RCU read lock, as in the following example:
+
+	void foo(struct task_struct *t, struct foo_data *f)
+	{
+		const struct cred *tcred;
+		...
+		rcu_read_lock();
+		tcred = __task_cred(t);
+		f->uid = tcred->uid;
+		f->gid = tcred->gid;
+		f->groups = get_group_info(tcred->groups);
+		rcu_read_unlock();
+		...
+	}
+
+A function need not get RCU read lock to use __task_cred() if it is holding a
+spinlock at the time as this implicitly holds the RCU read lock.
+
+Should it be necessary to hold another task's credentials for a long period of
+time, and possibly to sleep whilst doing so, then the caller should get a
+reference on them using:
+
+	const struct cred *get_task_cred(struct task_struct *task);
+
+This does all the RCU magic inside of it.  The caller must call put_cred() on
+the credentials so obtained when they're finished with.
+
+There are a couple of convenience functions to access bits of another task's
+credentials, hiding the RCU magic from the caller:
+
+	uid_t task_uid(task)		Task's real UID
+	uid_t task_euid(task)		Task's effective UID
+
+If the caller is holding a spinlock or the RCU read lock at the time anyway,
+then:
+
+	__task_cred(task)->uid
+	__task_cred(task)->euid
+
+should be used instead.  Similarly, if multiple aspects of a task's credentials
+need to be accessed, RCU read lock or a spinlock should be used, __task_cred()
+called, the result stored in a temporary pointer and then the credential
+aspects called from that before dropping the lock.  This prevents the
+potentially expensive RCU magic from being invoked multiple times.
+
+Should some other single aspect of another task's credentials need to be
+accessed, then this can be used:
+
+	task_cred_xxx(task, member)
+
+where 'member' is a non-pointer member of the cred struct.  For instance:
+
+	uid_t task_cred_xxx(task, suid);
+
+will retrieve 'struct cred::suid' from the task, doing the appropriate RCU
+magic.  This may not be used for pointer members as what they point to may
+disappear the moment the RCU read lock is dropped.
+
+
+ALTERING CREDENTIALS
+--------------------
+
+As previously mentioned, a task may only alter its own credentials, and may not
+alter those of another task.  This means that it doesn't need to use any
+locking to alter its own credentials.
+
+To alter the current process's credentials, a function should first prepare a
+new set of credentials by calling:
+
+	struct cred *prepare_creds(void);
+
+this locks current->cred_replace_mutex and then allocates and constructs a
+duplicate of the current process's credentials, returning with the mutex still
+held if successful.  It returns NULL if not successful (out of memory).
+
+The mutex prevents ptrace() from altering the ptrace state of a process whilst
+security checks on credentials construction and changing is taking place as
+the ptrace state may alter the outcome, particularly in the case of execve().
+
+The new credentials set should be altered appropriately, and any security
+checks and hooks done.  Both the current and the proposed sets of credentials
+are available for this purpose as current_cred() will return the current set
+still at this point.
+
+
+When the credential set is ready, it should be committed to the current process
+by calling:
+
+	int commit_creds(struct cred *new);
+
+This will alter various aspects of the credentials and the process, giving the
+LSM a chance to do likewise, then it will use rcu_assign_pointer() to actually
+commit the new credentials to current->cred, it will release
+current->cred_replace_mutex to allow ptrace() to take place, and it will notify
+the scheduler and others of the changes.
+
+This function is guaranteed to return 0, so that it can be tail-called at the
+end of such functions as sys_setresuid().
+
+Note that this function consumes the caller's reference to the new credentials.
+The caller should _not_ call put_cred() on the new credentials afterwards.
+
+Furthermore, once this function has been called on a new set of credentials,
+those credentials may _not_ be changed further.
+
+
+Should the security checks fail or some other error occur after prepare_creds()
+has been called, then the following function should be invoked:
+
+	void abort_creds(struct cred *new);
+
+This releases the lock on current->cred_replace_mutex that prepare_creds() got
+and then releases the new credentials.
+
+
+A typical credentials alteration function would look something like this:
+
+	int alter_suid(uid_t suid)
+	{
+		struct cred *new;
+		int ret;
+
+		new = prepare_creds();
+		if (!new)
+			return -ENOMEM;
+
+		new->suid = suid;
+		ret = security_alter_suid(new);
+		if (ret < 0) {
+			abort_creds(new);
+			return ret;
+		}
+
+		return commit_creds(new);
+	}
+
+
+MANAGING CREDENTIALS
+--------------------
+
+There are some functions to help manage credentials:
+
+ (*) void put_cred(const struct cred *cred);
+
+     This releases a reference to the given set of credentials.  If the
+     reference count reaches zero, the credentials will be scheduled for
+     destruction by the RCU system.
+
+ (*) const struct cred *get_cred(const struct cred *cred);
+
+     This gets a reference on a live set of credentials, returning a pointer to
+     that set of credentials.
+
+ (*) struct cred *get_new_cred(struct cred *cred);
+
+     This gets a reference on a set of credentials that is under construction
+     and is thus still mutable, returning a pointer to that set of credentials.
+
+
+=====================
+OPEN FILE CREDENTIALS
+=====================
+
+When a new file is opened, a reference is obtained on the opening task's
+credentials and this is attached to the file struct as 'f_cred' in place of
+'f_uid' and 'f_gid'.  Code that used to access file->f_uid and file->f_gid
+should now access file->f_cred->fsuid and file->f_cred->fsgid.
+
+It is safe to access f_cred without the use of RCU or locking because the
+pointer will not change over the lifetime of the file struct, and nor will the
+contents of the cred struct pointed to, barring the exceptions listed above
+(see the Task Credentials section).
+
+
+=======================================
+OVERRIDING THE VFS'S USE OF CREDENTIALS
+=======================================
+
+Under some circumstances it is desirable to override the credentials used by
+the VFS, and that can be done by calling into such as vfs_mkdir() with a
+different set of credentials.  This is done in the following places:
+
+ (*) sys_faccessat().
+
+ (*) do_coredump().
+
+ (*) nfs4recover.c.

Documentation/cris/README

@@ -27,7 +27,7 @@ operating system.
 The ETRAX 100LX chip
 --------------------
 
-For reference, plase see the press-release:
+For reference, please see the press-release:
 
 http://www.axis.com/news/us/001101_etrax.htm
 

Documentation/development-process/1.Intro

@@ -0,0 +1,274 @@
+1: A GUIDE TO THE KERNEL DEVELOPMENT PROCESS
+
+The purpose of this document is to help developers (and their managers)
+work with the development community with a minimum of frustration.  It is
+an attempt to document how this community works in a way which is
+accessible to those who are not intimately familiar with Linux kernel
+development (or, indeed, free software development in general).  While
+there is some technical material here, this is very much a process-oriented
+discussion which does not require a deep knowledge of kernel programming to
+understand.
+
+
+1.1: EXECUTIVE SUMMARY
+
+The rest of this section covers the scope of the kernel development process
+and the kinds of frustrations that developers and their employers can
+encounter there.  There are a great many reasons why kernel code should be
+merged into the official ("mainline") kernel, including automatic
+availability to users, community support in many forms, and the ability to
+influence the direction of kernel development.  Code contributed to the
+Linux kernel must be made available under a GPL-compatible license.
+
+Section 2 introduces the development process, the kernel release cycle, and
+the mechanics of the merge window.  The various phases in the patch
+development, review, and merging cycle are covered.  There is some
+discussion of tools and mailing lists.  Developers wanting to get started
+with kernel development are encouraged to track down and fix bugs as an
+initial exercise.
+
+Section 3 covers early-stage project planning, with an emphasis on
+involving the development community as soon as possible.
+
+Section 4 is about the coding process; several pitfalls which have been
+encountered by other developers are discussed.  Some requirements for
+patches are covered, and there is an introduction to some of the tools
+which can help to ensure that kernel patches are correct.
+
+Section 5 talks about the process of posting patches for review.  To be
+taken seriously by the development community, patches must be properly
+formatted and described, and they must be sent to the right place.
+Following the advice in this section should help to ensure the best
+possible reception for your work.
+
+Section 6 covers what happens after posting patches; the job is far from
+done at that point.  Working with reviewers is a crucial part of the
+development process; this section offers a number of tips on how to avoid
+problems at this important stage.  Developers are cautioned against
+assuming that the job is done when a patch is merged into the mainline.
+
+Section 7 introduces a couple of "advanced" topics: managing patches with
+git and reviewing patches posted by others.
+
+Section 8 concludes the document with pointers to sources for more
+information on kernel development.
+
+
+1.2: WHAT THIS DOCUMENT IS ABOUT
+
+The Linux kernel, at over 6 million lines of code and well over 1000 active
+contributors, is one of the largest and most active free software projects
+in existence.  Since its humble beginning in 1991, this kernel has evolved
+into a best-of-breed operating system component which runs on pocket-sized
+digital music players, desktop PCs, the largest supercomputers in
+existence, and all types of systems in between.  It is a robust, efficient,
+and scalable solution for almost any situation.
+
+With the growth of Linux has come an increase in the number of developers
+(and companies) wishing to participate in its development.  Hardware
+vendors want to ensure that Linux supports their products well, making
+those products attractive to Linux users.  Embedded systems vendors, who
+use Linux as a component in an integrated product, want Linux to be as
+capable and well-suited to the task at hand as possible.  Distributors and
+other software vendors who base their products on Linux have a clear
+interest in the capabilities, performance, and reliability of the Linux
+kernel.  And end users, too, will often wish to change Linux to make it
+better suit their needs.
+
+One of the most compelling features of Linux is that it is accessible to
+these developers; anybody with the requisite skills can improve Linux and
+influence the direction of its development.  Proprietary products cannot
+offer this kind of openness, which is a characteristic of the free software
+process.  But, if anything, the kernel is even more open than most other
+free software projects.  A typical three-month kernel development cycle can
+involve over 1000 developers working for more than 100 different companies
+(or for no company at all).
+
+Working with the kernel development community is not especially hard.  But,
+that notwithstanding, many potential contributors have experienced
+difficulties when trying to do kernel work.  The kernel community has
+evolved its own distinct ways of operating which allow it to function
+smoothly (and produce a high-quality product) in an environment where
+thousands of lines of code are being changed every day.  So it is not
+surprising that Linux kernel development process differs greatly from
+proprietary development methods.
+
+The kernel's development process may come across as strange and
+intimidating to new developers, but there are good reasons and solid
+experience behind it.  A developer who does not understand the kernel
+community's ways (or, worse, who tries to flout or circumvent them) will
+have a frustrating experience in store.  The development community, while
+being helpful to those who are trying to learn, has little time for those
+who will not listen or who do not care about the development process.
+
+It is hoped that those who read this document will be able to avoid that
+frustrating experience.  There is a lot of material here, but the effort
+involved in reading it will be repaid in short order.  The development
+community is always in need of developers who will help to make the kernel
+better; the following text should help you - or those who work for you -
+join our community.
+
+
+1.3: CREDITS
+
+This document was written by Jonathan Corbet, corbet@lwn.net.  It has been
+improved by comments from Johannes Berg, James Berry, Alex Chiang, Roland
+Dreier, Randy Dunlap, Jake Edge, Jiri Kosina, Matt Mackall, Arthur Marsh,
+Amanda McPherson, Andrew Morton, Andrew Price, Tsugikazu Shibata, and
+Jochen Voß. 
+
+This work was supported by the Linux Foundation; thanks especially to
+Amanda McPherson, who saw the value of this effort and made it all happen.
+
+
+1.4: THE IMPORTANCE OF GETTING CODE INTO THE MAINLINE
+
+Some companies and developers occasionally wonder why they should bother
+learning how to work with the kernel community and get their code into the
+mainline kernel (the "mainline" being the kernel maintained by Linus
+Torvalds and used as a base by Linux distributors).  In the short term,
+contributing code can look like an avoidable expense; it seems easier to
+just keep the code separate and support users directly.  The truth of the
+matter is that keeping code separate ("out of tree") is a false economy.
+
+As a way of illustrating the costs of out-of-tree code, here are a few
+relevant aspects of the kernel development process; most of these will be
+discussed in greater detail later in this document.  Consider:
+
+- Code which has been merged into the mainline kernel is available to all
+  Linux users.  It will automatically be present on all distributions which
+  enable it.  There is no need for driver disks, downloads, or the hassles
+  of supporting multiple versions of multiple distributions; it all just
+  works, for the developer and for the user.  Incorporation into the
+  mainline solves a large number of distribution and support problems.
+
+- While kernel developers strive to maintain a stable interface to user
+  space, the internal kernel API is in constant flux.  The lack of a stable
+  internal interface is a deliberate design decision; it allows fundamental
+  improvements to be made at any time and results in higher-quality code.
+  But one result of that policy is that any out-of-tree code requires
+  constant upkeep if it is to work with new kernels.  Maintaining
+  out-of-tree code requires significant amounts of work just to keep that
+  code working.
+
+  Code which is in the mainline, instead, does not require this work as the
+  result of a simple rule requiring any developer who makes an API change
+  to also fix any code that breaks as the result of that change.  So code
+  which has been merged into the mainline has significantly lower
+  maintenance costs.
+
+- Beyond that, code which is in the kernel will often be improved by other
+  developers.  Surprising results can come from empowering your user
+  community and customers to improve your product.
+
+- Kernel code is subjected to review, both before and after merging into
+  the mainline.  No matter how strong the original developer's skills are,
+  this review process invariably finds ways in which the code can be
+  improved.  Often review finds severe bugs and security problems.  This is
+  especially true for code which has been developed in a closed
+  environment; such code benefits strongly from review by outside
+  developers.  Out-of-tree code is lower-quality code.
+
+- Participation in the development process is your way to influence the
+  direction of kernel development.  Users who complain from the sidelines
+  are heard, but active developers have a stronger voice - and the ability
+  to implement changes which make the kernel work better for their needs.
+
+- When code is maintained separately, the possibility that a third party
+  will contribute a different implementation of a similar feature always
+  exists.  Should that happen, getting your code merged will become much
+  harder - to the point of impossibility.  Then you will be faced with the
+  unpleasant alternatives of either (1) maintaining a nonstandard feature
+  out of tree indefinitely, or (2) abandoning your code and migrating your
+  users over to the in-tree version.
+
+- Contribution of code is the fundamental action which makes the whole
+  process work.  By contributing your code you can add new functionality to
+  the kernel and provide capabilities and examples which are of use to
+  other kernel developers.  If you have developed code for Linux (or are
+  thinking about doing so), you clearly have an interest in the continued
+  success of this platform; contributing code is one of the best ways to
+  help ensure that success.
+
+All of the reasoning above applies to any out-of-tree kernel code,
+including code which is distributed in proprietary, binary-only form.
+There are, however, additional factors which should be taken into account
+before considering any sort of binary-only kernel code distribution.  These
+include:
+
+- The legal issues around the distribution of proprietary kernel modules
+  are cloudy at best; quite a few kernel copyright holders believe that
+  most binary-only modules are derived products of the kernel and that, as
+  a result, their distribution is a violation of the GNU General Public
+  license (about which more will be said below).  Your author is not a
+  lawyer, and nothing in this document can possibly be considered to be
+  legal advice.  The true legal status of closed-source modules can only be
+  determined by the courts.  But the uncertainty which haunts those modules
+  is there regardless.
+
+- Binary modules greatly increase the difficulty of debugging kernel
+  problems, to the point that most kernel developers will not even try.  So
+  the distribution of binary-only modules will make it harder for your
+  users to get support from the community.
+
+- Support is also harder for distributors of binary-only modules, who must
+  provide a version of the module for every distribution and every kernel
+  version they wish to support.  Dozens of builds of a single module can
+  be required to provide reasonably comprehensive coverage, and your users
+  will have to upgrade your module separately every time they upgrade their
+  kernel.
+
+- Everything that was said above about code review applies doubly to
+  closed-source code.  Since this code is not available at all, it cannot
+  have been reviewed by the community and will, beyond doubt, have serious
+  problems. 
+
+Makers of embedded systems, in particular, may be tempted to disregard much
+of what has been said in this section in the belief that they are shipping
+a self-contained product which uses a frozen kernel version and requires no
+more development after its release.  This argument misses the value of
+widespread code review and the value of allowing your users to add
+capabilities to your product.  But these products, too, have a limited
+commercial life, after which a new version must be released.  At that
+point, vendors whose code is in the mainline and well maintained will be
+much better positioned to get the new product ready for market quickly.
+
+
+1.5: LICENSING
+
+Code is contributed to the Linux kernel under a number of licenses, but all
+code must be compatible with version 2 of the GNU General Public License
+(GPLv2), which is the license covering the kernel distribution as a whole.
+In practice, that means that all code contributions are covered either by
+GPLv2 (with, optionally, language allowing distribution under later
+versions of the GPL) or the three-clause BSD license.  Any contributions
+which are not covered by a compatible license will not be accepted into the
+kernel.
+
+Copyright assignments are not required (or requested) for code contributed
+to the kernel.  All code merged into the mainline kernel retains its
+original ownership; as a result, the kernel now has thousands of owners.
+
+One implication of this ownership structure is that any attempt to change
+the licensing of the kernel is doomed to almost certain failure.  There are
+few practical scenarios where the agreement of all copyright holders could
+be obtained (or their code removed from the kernel).  So, in particular,
+there is no prospect of a migration to version 3 of the GPL in the
+foreseeable future.
+
+It is imperative that all code contributed to the kernel be legitimately
+free software.  For that reason, code from anonymous (or pseudonymous)
+contributors will not be accepted.  All contributors are required to "sign
+off" on their code, stating that the code can be distributed with the
+kernel under the GPL.  Code which has not been licensed as free software by
+its owner, or which risks creating copyright-related problems for the
+kernel (such as code which derives from reverse-engineering efforts lacking
+proper safeguards) cannot be contributed.
+
+Questions about copyright-related issues are common on Linux development
+mailing lists.  Such questions will normally receive no shortage of
+answers, but one should bear in mind that the people answering those
+questions are not lawyers and cannot provide legal advice.  If you have
+legal questions relating to Linux source code, there is no substitute for
+talking with a lawyer who understands this field.  Relying on answers
+obtained on technical mailing lists is a risky affair.

Documentation/development-process/2.Process

@@ -0,0 +1,459 @@
+2: HOW THE DEVELOPMENT PROCESS WORKS
+
+Linux kernel development in the early 1990's was a pretty loose affair,
+with relatively small numbers of users and developers involved.  With a
+user base in the millions and with some 2,000 developers involved over the
+course of one year, the kernel has since had to evolve a number of
+processes to keep development happening smoothly.  A solid understanding of
+how the process works is required in order to be an effective part of it.
+
+
+2.1: THE BIG PICTURE
+
+The kernel developers use a loosely time-based release process, with a new
+major kernel release happening every two or three months.  The recent
+release history looks like this:
+
+	2.6.26	July 13, 2008
+	2.6.25	April 16, 2008
+	2.6.24	January 24, 2008
+	2.6.23	October 9, 2007
+	2.6.22	July 8, 2007
+	2.6.21	April 25, 2007
+	2.6.20	February 4, 2007
+
+Every 2.6.x release is a major kernel release with new features, internal
+API changes, and more.  A typical 2.6 release can contain over 10,000
+changesets with changes to several hundred thousand lines of code.  2.6 is
+thus the leading edge of Linux kernel development; the kernel uses a
+rolling development model which is continually integrating major changes.
+
+A relatively straightforward discipline is followed with regard to the
+merging of patches for each release.  At the beginning of each development
+cycle, the "merge window" is said to be open.  At that time, code which is
+deemed to be sufficiently stable (and which is accepted by the development
+community) is merged into the mainline kernel.  The bulk of changes for a
+new development cycle (and all of the major changes) will be merged during
+this time, at a rate approaching 1,000 changes ("patches," or "changesets")
+per day.
+
+(As an aside, it is worth noting that the changes integrated during the
+merge window do not come out of thin air; they have been collected, tested,
+and staged ahead of time.  How that process works will be described in
+detail later on).
+
+The merge window lasts for two weeks.  At the end of this time, Linus
+Torvalds will declare that the window is closed and release the first of
+the "rc" kernels.  For the kernel which is destined to be 2.6.26, for
+example, the release which happens at the end of the merge window will be
+called 2.6.26-rc1.  The -rc1 release is the signal that the time to merge
+new features has passed, and that the time to stabilize the next kernel has
+begun.
+
+Over the next six to ten weeks, only patches which fix problems should be
+submitted to the mainline.  On occasion a more significant change will be
+allowed, but such occasions are rare; developers who try to merge new
+features outside of the merge window tend to get an unfriendly reception.
+As a general rule, if you miss the merge window for a given feature, the
+best thing to do is to wait for the next development cycle.  (An occasional
+exception is made for drivers for previously-unsupported hardware; if they
+touch no in-tree code, they cannot cause regressions and should be safe to
+add at any time).
+
+As fixes make their way into the mainline, the patch rate will slow over
+time.  Linus releases new -rc kernels about once a week; a normal series
+will get up to somewhere between -rc6 and -rc9 before the kernel is
+considered to be sufficiently stable and the final 2.6.x release is made.
+At that point the whole process starts over again.
+
+As an example, here is how the 2.6.25 development cycle went (all dates in
+2008): 
+
+	January 24	2.6.24 stable release
+	February 10	2.6.25-rc1, merge window closes
+	February 15	2.6.25-rc2
+	February 24	2.6.25-rc3
+	March 4	 	2.6.25-rc4
+	March 9		2.6.25-rc5
+	March 16	2.6.25-rc6
+	March 25	2.6.25-rc7
+	April 1		2.6.25-rc8
+	April 11	2.6.25-rc9
+	April 16	2.6.25 stable release
+
+How do the developers decide when to close the development cycle and create
+the stable release?  The most significant metric used is the list of
+regressions from previous releases.  No bugs are welcome, but those which
+break systems which worked in the past are considered to be especially
+serious.  For this reason, patches which cause regressions are looked upon
+unfavorably and are quite likely to be reverted during the stabilization
+period. 
+
+The developers' goal is to fix all known regressions before the stable
+release is made.  In the real world, this kind of perfection is hard to
+achieve; there are just too many variables in a project of this size.
+There comes a point where delaying the final release just makes the problem
+worse; the pile of changes waiting for the next merge window will grow
+larger, creating even more regressions the next time around.  So most 2.6.x
+kernels go out with a handful of known regressions though, hopefully, none
+of them are serious.
+
+Once a stable release is made, its ongoing maintenance is passed off to the
+"stable team," currently comprised of Greg Kroah-Hartman and Chris Wright.
+The stable team will release occasional updates to the stable release using
+the 2.6.x.y numbering scheme.  To be considered for an update release, a
+patch must (1) fix a significant bug, and (2) already be merged into the
+mainline for the next development kernel.  Continuing our 2.6.25 example,
+the history (as of this writing) is:
+
+	May 1		2.6.25.1
+	May 6		2.6.25.2 
+	May 9		2.6.25.3 
+	May 15		2.6.25.4
+	June 7		2.6.25.5
+	June 9		2.6.25.6
+	June 16		2.6.25.7
+	June 21		2.6.25.8
+	June 24		2.6.25.9
+
+Stable updates for a given kernel are made for approximately six months;
+after that, the maintenance of stable releases is solely the responsibility
+of the distributors which have shipped that particular kernel.
+
+
+2.2: THE LIFECYCLE OF A PATCH
+
+Patches do not go directly from the developer's keyboard into the mainline
+kernel.  There is, instead, a somewhat involved (if somewhat informal)
+process designed to ensure that each patch is reviewed for quality and that
+each patch implements a change which is desirable to have in the mainline.
+This process can happen quickly for minor fixes, or, in the case of large
+and controversial changes, go on for years.  Much developer frustration
+comes from a lack of understanding of this process or from attempts to
+circumvent it.  
+
+In the hopes of reducing that frustration, this document will describe how
+a patch gets into the kernel.  What follows below is an introduction which
+describes the process in a somewhat idealized way.  A much more detailed
+treatment will come in later sections.
+
+The stages that a patch goes through are, generally:
+
+ - Design.  This is where the real requirements for the patch - and the way
+   those requirements will be met - are laid out.  Design work is often
+   done without involving the community, but it is better to do this work
+   in the open if at all possible; it can save a lot of time redesigning
+   things later.
+
+ - Early review.  Patches are posted to the relevant mailing list, and
+   developers on that list reply with any comments they may have.  This
+   process should turn up any major problems with a patch if all goes
+   well.
+
+ - Wider review.  When the patch is getting close to ready for mainline
+   inclusion, it will be accepted by a relevant subsystem maintainer -
+   though this acceptance is not a guarantee that the patch will make it
+   all the way to the mainline.  The patch will show up in the maintainer's
+   subsystem tree and into the staging trees (described below).  When the
+   process works, this step leads to more extensive review of the patch and
+   the discovery of any problems resulting from the integration of this
+   patch with work being done by others.
+
+ - Merging into the mainline.  Eventually, a successful patch will be
+   merged into the mainline repository managed by Linus Torvalds.  More
+   comments and/or problems may surface at this time; it is important that
+   the developer be responsive to these and fix any issues which arise.
+
+ - Stable release.  The number of users potentially affected by the patch
+   is now large, so, once again, new problems may arise.
+
+ - Long-term maintenance.  While it is certainly possible for a developer
+   to forget about code after merging it, that sort of behavior tends to
+   leave a poor impression in the development community.  Merging code
+   eliminates some of the maintenance burden, in that others will fix
+   problems caused by API changes.  But the original developer should
+   continue to take responsibility for the code if it is to remain useful
+   in the longer term.
+
+One of the largest mistakes made by kernel developers (or their employers)
+is to try to cut the process down to a single "merging into the mainline"
+step.  This approach invariably leads to frustration for everybody
+involved.
+
+
+2.3: HOW PATCHES GET INTO THE KERNEL
+
+There is exactly one person who can merge patches into the mainline kernel
+repository: Linus Torvalds.  But, of the over 12,000 patches which went
+into the 2.6.25 kernel, only 250 (around 2%) were directly chosen by Linus
+himself.  The kernel project has long since grown to a size where no single
+developer could possibly inspect and select every patch unassisted.  The
+way the kernel developers have addressed this growth is through the use of
+a lieutenant system built around a chain of trust.
+
+The kernel code base is logically broken down into a set of subsystems:
+networking, specific architecture support, memory management, video
+devices, etc.  Most subsystems have a designated maintainer, a developer
+who has overall responsibility for the code within that subsystem.  These
+subsystem maintainers are the gatekeepers (in a loose way) for the portion
+of the kernel they manage; they are the ones who will (usually) accept a
+patch for inclusion into the mainline kernel.
+
+Subsystem maintainers each manage their own version of the kernel source
+tree, usually (but certainly not always) using the git source management
+tool.  Tools like git (and related tools like quilt or mercurial) allow
+maintainers to track a list of patches, including authorship information
+and other metadata.  At any given time, the maintainer can identify which
+patches in his or her repository are not found in the mainline.
+
+When the merge window opens, top-level maintainers will ask Linus to "pull"
+the patches they have selected for merging from their repositories.  If
+Linus agrees, the stream of patches will flow up into his repository,
+becoming part of the mainline kernel.  The amount of attention that Linus
+pays to specific patches received in a pull operation varies.  It is clear
+that, sometimes, he looks quite closely.  But, as a general rule, Linus
+trusts the subsystem maintainers to not send bad patches upstream.
+
+Subsystem maintainers, in turn, can pull patches from other maintainers.
+For example, the networking tree is built from patches which accumulated
+first in trees dedicated to network device drivers, wireless networking,
+etc.  This chain of repositories can be arbitrarily long, though it rarely
+exceeds two or three links.  Since each maintainer in the chain trusts
+those managing lower-level trees, this process is known as the "chain of
+trust." 
+
+Clearly, in a system like this, getting patches into the kernel depends on
+finding the right maintainer.  Sending patches directly to Linus is not
+normally the right way to go.
+
+
+2.4: STAGING TREES
+
+The chain of subsystem trees guides the flow of patches into the kernel,
+but it also raises an interesting question: what if somebody wants to look
+at all of the patches which are being prepared for the next merge window?
+Developers will be interested in what other changes are pending to see
+whether there are any conflicts to worry about; a patch which changes a
+core kernel function prototype, for example, will conflict with any other
+patches which use the older form of that function.  Reviewers and testers
+want access to the changes in their integrated form before all of those
+changes land in the mainline kernel.  One could pull changes from all of
+the interesting subsystem trees, but that would be a big and error-prone
+job.
+
+The answer comes in the form of staging trees, where subsystem trees are
+collected for testing and review.  The older of these trees, maintained by
+Andrew Morton, is called "-mm" (for memory management, which is how it got
+started).  The -mm tree integrates patches from a long list of subsystem
+trees; it also has some patches aimed at helping with debugging.  
+
+Beyond that, -mm contains a significant collection of patches which have
+been selected by Andrew directly.  These patches may have been posted on a
+mailing list, or they may apply to a part of the kernel for which there is
+no designated subsystem tree.  As a result, -mm operates as a sort of
+subsystem tree of last resort; if there is no other obvious path for a
+patch into the mainline, it is likely to end up in -mm.  Miscellaneous
+patches which accumulate in -mm will eventually either be forwarded on to
+an appropriate subsystem tree or be sent directly to Linus.  In a typical
+development cycle, approximately 10% of the patches going into the mainline
+get there via -mm.
+
+The current -mm patch can always be found from the front page of
+
+	http://kernel.org/
+
+Those who want to see the current state of -mm can get the "-mm of the
+moment" tree, found at:
+
+	http://userweb.kernel.org/~akpm/mmotm/
+
+Use of the MMOTM tree is likely to be a frustrating experience, though;
+there is a definite chance that it will not even compile.
+
+The other staging tree, started more recently, is linux-next, maintained by
+Stephen Rothwell.  The linux-next tree is, by design, a snapshot of what
+the mainline is expected to look like after the next merge window closes.
+Linux-next trees are announced on the linux-kernel and linux-next mailing
+lists when they are assembled; they can be downloaded from:
+
+	http://www.kernel.org/pub/linux/kernel/people/sfr/linux-next/
+
+Some information about linux-next has been gathered at:
+
+	http://linux.f-seidel.de/linux-next/pmwiki/
+
+How the linux-next tree will fit into the development process is still
+changing.  As of this writing, the first full development cycle involving
+linux-next (2.6.26) is coming to an end; thus far, it has proved to be a
+valuable resource for finding and fixing integration problems before the
+beginning of the merge window.  See http://lwn.net/Articles/287155/ for
+more information on how linux-next has worked to set up the 2.6.27 merge
+window.
+
+Some developers have begun to suggest that linux-next should be used as the
+target for future development as well.  The linux-next tree does tend to be
+far ahead of the mainline and is more representative of the tree into which
+any new work will be merged.  The downside to this idea is that the
+volatility of linux-next tends to make it a difficult development target.
+See http://lwn.net/Articles/289013/ for more information on this topic, and
+stay tuned; much is still in flux where linux-next is involved.
+
+
+2.5: TOOLS
+
+As can be seen from the above text, the kernel development process depends
+heavily on the ability to herd collections of patches in various
+directions.  The whole thing would not work anywhere near as well as it
+does without suitably powerful tools.  Tutorials on how to use these tools
+are well beyond the scope of this document, but there is space for a few
+pointers.
+
+By far the dominant source code management system used by the kernel
+community is git.  Git is one of a number of distributed version control
+systems being developed in the free software community.  It is well tuned
+for kernel development, in that it performs quite well when dealing with
+large repositories and large numbers of patches.  It also has a reputation
+for being difficult to learn and use, though it has gotten better over
+time.  Some sort of familiarity with git is almost a requirement for kernel
+developers; even if they do not use it for their own work, they'll need git
+to keep up with what other developers (and the mainline) are doing.
+
+Git is now packaged by almost all Linux distributions.  There is a home
+page at 
+
+	http://git.or.cz/
+
+That page has pointers to documentation and tutorials.  One should be
+aware, in particular, of the Kernel Hacker's Guide to git, which has
+information specific to kernel development:
+
+	http://linux.yyz.us/git-howto.html
+
+Among the kernel developers who do not use git, the most popular choice is
+almost certainly Mercurial:
+
+	http://www.selenic.com/mercurial/
+
+Mercurial shares many features with git, but it provides an interface which
+many find easier to use.
+
+The other tool worth knowing about is Quilt:
+
+	http://savannah.nongnu.org/projects/quilt/
+
+Quilt is a patch management system, rather than a source code management
+system.  It does not track history over time; it is, instead, oriented
+toward tracking a specific set of changes against an evolving code base.
+Some major subsystem maintainers use quilt to manage patches intended to go
+upstream.  For the management of certain kinds of trees (-mm, for example),
+quilt is the best tool for the job.
+
+
+2.6: MAILING LISTS
+
+A great deal of Linux kernel development work is done by way of mailing
+lists.  It is hard to be a fully-functioning member of the community
+without joining at least one list somewhere.  But Linux mailing lists also
+represent a potential hazard to developers, who risk getting buried under a
+load of electronic mail, running afoul of the conventions used on the Linux
+lists, or both.
+
+Most kernel mailing lists are run on vger.kernel.org; the master list can
+be found at:
+
+	http://vger.kernel.org/vger-lists.html
+
+There are lists hosted elsewhere, though; a number of them are at
+lists.redhat.com.
+
+The core mailing list for kernel development is, of course, linux-kernel.
+This list is an intimidating place to be; volume can reach 500 messages per
+day, the amount of noise is high, the conversation can be severely
+technical, and participants are not always concerned with showing a high
+degree of politeness.  But there is no other place where the kernel
+development community comes together as a whole; developers who avoid this
+list will miss important information.
+
+There are a few hints which can help with linux-kernel survival:
+
+- Have the list delivered to a separate folder, rather than your main
+  mailbox.  One must be able to ignore the stream for sustained periods of
+  time.
+
+- Do not try to follow every conversation - nobody else does.  It is
+  important to filter on both the topic of interest (though note that
+  long-running conversations can drift away from the original subject
+  without changing the email subject line) and the people who are
+  participating.  
+
+- Do not feed the trolls.  If somebody is trying to stir up an angry
+  response, ignore them.
+
+- When responding to linux-kernel email (or that on other lists) preserve
+  the Cc: header for all involved.  In the absence of a strong reason (such
+  as an explicit request), you should never remove recipients.  Always make
+  sure that the person you are responding to is in the Cc: list.  This
+  convention also makes it unnecessary to explicitly ask to be copied on
+  replies to your postings.
+
+- Search the list archives (and the net as a whole) before asking
+  questions.  Some developers can get impatient with people who clearly
+  have not done their homework.
+
+- Avoid top-posting (the practice of putting your answer above the quoted
+  text you are responding to).  It makes your response harder to read and
+  makes a poor impression.
+
+- Ask on the correct mailing list.  Linux-kernel may be the general meeting
+  point, but it is not the best place to find developers from all
+  subsystems.
+
+The last point - finding the correct mailing list - is a common place for
+beginning developers to go wrong.  Somebody who asks a networking-related
+question on linux-kernel will almost certainly receive a polite suggestion
+to ask on the netdev list instead, as that is the list frequented by most
+networking developers.  Other lists exist for the SCSI, video4linux, IDE,
+filesystem, etc. subsystems.  The best place to look for mailing lists is
+in the MAINTAINERS file packaged with the kernel source.
+
+
+2.7: GETTING STARTED WITH KERNEL DEVELOPMENT
+
+Questions about how to get started with the kernel development process are
+common - from both individuals and companies.  Equally common are missteps
+which make the beginning of the relationship harder than it has to be.
+
+Companies often look to hire well-known developers to get a development
+group started.  This can, in fact, be an effective technique.  But it also
+tends to be expensive and does not do much to grow the pool of experienced
+kernel developers.  It is possible to bring in-house developers up to speed
+on Linux kernel development, given the investment of a bit of time.  Taking
+this time can endow an employer with a group of developers who understand
+the kernel and the company both, and who can help to train others as well.
+Over the medium term, this is often the more profitable approach.
+
+Individual developers are often, understandably, at a loss for a place to
+start.  Beginning with a large project can be intimidating; one often wants
+to test the waters with something smaller first.  This is the point where
+some developers jump into the creation of patches fixing spelling errors or
+minor coding style issues.  Unfortunately, such patches create a level of
+noise which is distracting for the development community as a whole, so,
+increasingly, they are looked down upon.  New developers wishing to
+introduce themselves to the community will not get the sort of reception
+they wish for by these means.
+
+Andrew Morton gives this advice for aspiring kernel developers
+
+	The #1 project for all kernel beginners should surely be "make sure
+	that the kernel runs perfectly at all times on all machines which
+	you can lay your hands on".  Usually the way to do this is to work
+	with others on getting things fixed up (this can require
+	persistence!) but that's fine - it's a part of kernel development.
+
+(http://lwn.net/Articles/283982/).
+
+In the absence of obvious problems to fix, developers are advised to look
+at the current lists of regressions and open bugs in general.  There is
+never any shortage of issues in need of fixing; by addressing these issues,
+developers will gain experience with the process while, at the same time,
+building respect with the rest of the development community.

Documentation/development-process/3.Early-stage

@@ -0,0 +1,195 @@
+3: EARLY-STAGE PLANNING
+
+When contemplating a Linux kernel development project, it can be tempting
+to jump right in and start coding.  As with any significant project,
+though, much of the groundwork for success is best laid before the first
+line of code is written.  Some time spent in early planning and
+communication can save far more time later on.
+
+
+3.1: SPECIFYING THE PROBLEM
+
+Like any engineering project, a successful kernel enhancement starts with a
+clear description of the problem to be solved.  In some cases, this step is
+easy: when a driver is needed for a specific piece of hardware, for
+example.  In others, though, it is tempting to confuse the real problem
+with the proposed solution, and that can lead to difficulties.
+
+Consider an example: some years ago, developers working with Linux audio
+sought a way to run applications without dropouts or other artifacts caused
+by excessive latency in the system.  The solution they arrived at was a
+kernel module intended to hook into the Linux Security Module (LSM)
+framework; this module could be configured to give specific applications
+access to the realtime scheduler.  This module was implemented and sent to
+the linux-kernel mailing list, where it immediately ran into problems.
+
+To the audio developers, this security module was sufficient to solve their
+immediate problem.  To the wider kernel community, though, it was seen as a
+misuse of the LSM framework (which is not intended to confer privileges
+onto processes which they would not otherwise have) and a risk to system
+stability.  Their preferred solutions involved realtime scheduling access
+via the rlimit mechanism for the short term, and ongoing latency reduction
+work in the long term.
+
+The audio community, however, could not see past the particular solution
+they had implemented; they were unwilling to accept alternatives.  The
+resulting disagreement left those developers feeling disillusioned with the
+entire kernel development process; one of them went back to an audio list
+and posted this:
+
+	There are a number of very good Linux kernel developers, but they
+	tend to get outshouted by a large crowd of arrogant fools. Trying
+	to communicate user requirements to these people is a waste of
+	time. They are much too "intelligent" to listen to lesser mortals.
+
+(http://lwn.net/Articles/131776/).
+
+The reality of the situation was different; the kernel developers were far
+more concerned about system stability, long-term maintenance, and finding
+the right solution to the problem than they were with a specific module.
+The moral of the story is to focus on the problem - not a specific solution
+- and to discuss it with the development community before investing in the
+creation of a body of code.
+
+So, when contemplating a kernel development project, one should obtain
+answers to a short set of questions:
+
+ - What, exactly, is the problem which needs to be solved?
+
+ - Who are the users affected by this problem?  Which use cases should the
+   solution address?
+
+ - How does the kernel fall short in addressing that problem now?
+
+Only then does it make sense to start considering possible solutions.
+
+
+3.2: EARLY DISCUSSION
+
+When planning a kernel development project, it makes great sense to hold
+discussions with the community before launching into implementation.  Early
+communication can save time and trouble in a number of ways:
+
+ - It may well be that the problem is addressed by the kernel in ways which
+   you have not understood.  The Linux kernel is large and has a number of
+   features and capabilities which are not immediately obvious.  Not all
+   kernel capabilities are documented as well as one might like, and it is
+   easy to miss things.  Your author has seen the posting of a complete
+   driver which duplicated an existing driver that the new author had been
+   unaware of.  Code which reinvents existing wheels is not only wasteful;
+   it will also not be accepted into the mainline kernel.
+
+ - There may be elements of the proposed solution which will not be
+   acceptable for mainline merging.  It is better to find out about
+   problems like this before writing the code.
+
+ - It's entirely possible that other developers have thought about the
+   problem; they may have ideas for a better solution, and may be willing
+   to help in the creation of that solution.
+
+Years of experience with the kernel development community have taught a
+clear lesson: kernel code which is designed and developed behind closed
+doors invariably has problems which are only revealed when the code is
+released into the community.  Sometimes these problems are severe,
+requiring months or years of effort before the code can be brought up to
+the kernel community's standards.  Some examples include:
+
+ - The Devicescape network stack was designed and implemented for
+   single-processor systems.  It could not be merged into the mainline
+   until it was made suitable for multiprocessor systems.  Retrofitting
+   locking and such into code is a difficult task; as a result, the merging
+   of this code (now called mac80211) was delayed for over a year.
+
+ - The Reiser4 filesystem included a number of capabilities which, in the
+   core kernel developers' opinion, should have been implemented in the
+   virtual filesystem layer instead.  It also included features which could
+   not easily be implemented without exposing the system to user-caused
+   deadlocks.  The late revelation of these problems - and refusal to
+   address some of them - has caused Reiser4 to stay out of the mainline
+   kernel.
+
+ - The AppArmor security module made use of internal virtual filesystem
+   data structures in ways which were considered to be unsafe and
+   unreliable.  This code has since been significantly reworked, but
+   remains outside of the mainline.
+
+In each of these cases, a great deal of pain and extra work could have been
+avoided with some early discussion with the kernel developers.
+
+
+3.3: WHO DO YOU TALK TO?
+
+When developers decide to take their plans public, the next question will
+be: where do we start?  The answer is to find the right mailing list(s) and
+the right maintainer.  For mailing lists, the best approach is to look in
+the MAINTAINERS file for a relevant place to post.  If there is a suitable
+subsystem list, posting there is often preferable to posting on
+linux-kernel; you are more likely to reach developers with expertise in the
+relevant subsystem and the environment may be more supportive.
+
+Finding maintainers can be a bit harder.  Again, the MAINTAINERS file is
+the place to start.  That file tends to not always be up to date, though,
+and not all subsystems are represented there.  The person listed in the
+MAINTAINERS file may, in fact, not be the person who is actually acting in
+that role currently.  So, when there is doubt about who to contact, a
+useful trick is to use git (and "git log" in particular) to see who is
+currently active within the subsystem of interest.  Look at who is writing
+patches, and who, if anybody, is attaching Signed-off-by lines to those
+patches.  Those are the people who will be best placed to help with a new
+development project.
+
+If all else fails, talking to Andrew Morton can be an effective way to
+track down a maintainer for a specific piece of code.
+
+
+3.4: WHEN TO POST?
+
+If possible, posting your plans during the early stages can only be
+helpful.  Describe the problem being solved and any plans that have been
+made on how the implementation will be done.  Any information you can
+provide can help the development community provide useful input on the
+project.
+
+One discouraging thing which can happen at this stage is not a hostile
+reaction, but, instead, little or no reaction at all.  The sad truth of the
+matter is (1) kernel developers tend to be busy, (2) there is no shortage
+of people with grand plans and little code (or even prospect of code) to
+back them up, and (3) nobody is obligated to review or comment on ideas
+posted by others.  If a request-for-comments posting yields little in the
+way of comments, do not assume that it means there is no interest in the
+project.  Unfortunately, you also cannot assume that there are no problems
+with your idea.  The best thing to do in this situation is to proceed,
+keeping the community informed as you go.
+
+
+3.5: GETTING OFFICIAL BUY-IN
+
+If your work is being done in a corporate environment - as most Linux
+kernel work is - you must, obviously, have permission from suitably
+empowered managers before you can post your company's plans or code to a
+public mailing list.  The posting of code which has not been cleared for
+release under a GPL-compatible license can be especially problematic; the
+sooner that a company's management and legal staff can agree on the posting
+of a kernel development project, the better off everybody involved will be.
+
+Some readers may be thinking at this point that their kernel work is
+intended to support a product which does not yet have an officially
+acknowledged existence.  Revealing their employer's plans on a public
+mailing list may not be a viable option.  In cases like this, it is worth
+considering whether the secrecy is really necessary; there is often no real
+need to keep development plans behind closed doors.
+
+That said, there are also cases where a company legitimately cannot
+disclose its plans early in the development process.  Companies with
+experienced kernel developers may choose to proceed in an open-loop manner
+on the assumption that they will be able to avoid serious integration
+problems later.  For companies without that sort of in-house expertise, the
+best option is often to hire an outside developer to review the plans under
+a non-disclosure agreement.  The Linux Foundation operates an NDA program
+designed to help with this sort of situation; more information can be found
+at:
+
+    http://www.linuxfoundation.org/en/NDA_program
+
+This kind of review is often enough to avoid serious problems later on
+without requiring public disclosure of the project.

Documentation/development-process/4.Coding

@@ -0,0 +1,384 @@
+4: GETTING THE CODE RIGHT
+
+While there is much to be said for a solid and community-oriented design
+process, the proof of any kernel development project is in the resulting
+code.  It is the code which will be examined by other developers and merged
+(or not) into the mainline tree.  So it is the quality of this code which
+will determine the ultimate success of the project.
+
+This section will examine the coding process.  We'll start with a look at a
+number of ways in which kernel developers can go wrong.  Then the focus
+will shift toward doing things right and the tools which can help in that
+quest.
+
+
+4.1: PITFALLS
+
+* Coding style
+
+The kernel has long had a standard coding style, described in
+Documentation/CodingStyle.  For much of that time, the policies described
+in that file were taken as being, at most, advisory.  As a result, there is
+a substantial amount of code in the kernel which does not meet the coding
+style guidelines.  The presence of that code leads to two independent
+hazards for kernel developers.
+
+The first of these is to believe that the kernel coding standards do not
+matter and are not enforced.  The truth of the matter is that adding new
+code to the kernel is very difficult if that code is not coded according to
+the standard; many developers will request that the code be reformatted
+before they will even review it.  A code base as large as the kernel
+requires some uniformity of code to make it possible for developers to
+quickly understand any part of it.  So there is no longer room for
+strangely-formatted code.
+
+Occasionally, the kernel's coding style will run into conflict with an
+employer's mandated style.  In such cases, the kernel's style will have to
+win before the code can be merged.  Putting code into the kernel means
+giving up a degree of control in a number of ways - including control over
+how the code is formatted.
+
+The other trap is to assume that code which is already in the kernel is
+urgently in need of coding style fixes.  Developers may start to generate
+reformatting patches as a way of gaining familiarity with the process, or
+as a way of getting their name into the kernel changelogs - or both.  But
+pure coding style fixes are seen as noise by the development community;
+they tend to get a chilly reception.  So this type of patch is best
+avoided.  It is natural to fix the style of a piece of code while working
+on it for other reasons, but coding style changes should not be made for
+their own sake.
+
+The coding style document also should not be read as an absolute law which
+can never be transgressed.  If there is a good reason to go against the
+style (a line which becomes far less readable if split to fit within the
+80-column limit, for example), just do it.
+
+
+* Abstraction layers
+
+Computer Science professors teach students to make extensive use of
+abstraction layers in the name of flexibility and information hiding.
+Certainly the kernel makes extensive use of abstraction; no project
+involving several million lines of code could do otherwise and survive.
+But experience has shown that excessive or premature abstraction can be
+just as harmful as premature optimization.  Abstraction should be used to
+the level required and no further.
+
+At a simple level, consider a function which has an argument which is
+always passed as zero by all callers.  One could retain that argument just
+in case somebody eventually needs to use the extra flexibility that it
+provides.  By that time, though, chances are good that the code which
+implements this extra argument has been broken in some subtle way which was
+never noticed - because it has never been used.  Or, when the need for
+extra flexibility arises, it does not do so in a way which matches the
+programmer's early expectation.  Kernel developers will routinely submit
+patches to remove unused arguments; they should, in general, not be added
+in the first place.
+
+Abstraction layers which hide access to hardware - often to allow the bulk
+of a driver to be used with multiple operating systems - are especially
+frowned upon.  Such layers obscure the code and may impose a performance
+penalty; they do not belong in the Linux kernel.
+
+On the other hand, if you find yourself copying significant amounts of code
+from another kernel subsystem, it is time to ask whether it would, in fact,
+make sense to pull out some of that code into a separate library or to
+implement that functionality at a higher level.  There is no value in
+replicating the same code throughout the kernel.
+
+
+* #ifdef and preprocessor use in general
+
+The C preprocessor seems to present a powerful temptation to some C
+programmers, who see it as a way to efficiently encode a great deal of
+flexibility into a source file.  But the preprocessor is not C, and heavy
+use of it results in code which is much harder for others to read and
+harder for the compiler to check for correctness.  Heavy preprocessor use
+is almost always a sign of code which needs some cleanup work.
+
+Conditional compilation with #ifdef is, indeed, a powerful feature, and it
+is used within the kernel.  But there is little desire to see code which is
+sprinkled liberally with #ifdef blocks.  As a general rule, #ifdef use
+should be confined to header files whenever possible.
+Conditionally-compiled code can be confined to functions which, if the code
+is not to be present, simply become empty.  The compiler will then quietly
+optimize out the call to the empty function.  The result is far cleaner
+code which is easier to follow.
+
+C preprocessor macros present a number of hazards, including possible
+multiple evaluation of expressions with side effects and no type safety.
+If you are tempted to define a macro, consider creating an inline function
+instead.  The code which results will be the same, but inline functions are
+easier to read, do not evaluate their arguments multiple times, and allow
+the compiler to perform type checking on the arguments and return value.
+
+
+* Inline functions
+
+Inline functions present a hazard of their own, though.  Programmers can
+become enamored of the perceived efficiency inherent in avoiding a function
+call and fill a source file with inline functions.  Those functions,
+however, can actually reduce performance.  Since their code is replicated
+at each call site, they end up bloating the size of the compiled kernel.
+That, in turn, creates pressure on the processor's memory caches, which can
+slow execution dramatically.  Inline functions, as a rule, should be quite
+small and relatively rare.  The cost of a function call, after all, is not
+that high; the creation of large numbers of inline functions is a classic
+example of premature optimization.
+
+In general, kernel programmers ignore cache effects at their peril.  The
+classic time/space tradeoff taught in beginning data structures classes
+often does not apply to contemporary hardware.  Space *is* time, in that a
+larger program will run slower than one which is more compact.
+
+
+* Locking
+
+In May, 2006, the "Devicescape" networking stack was, with great
+fanfare, released under the GPL and made available for inclusion in the
+mainline kernel.  This donation was welcome news; support for wireless
+networking in Linux was considered substandard at best, and the Devicescape
+stack offered the promise of fixing that situation.  Yet, this code did not
+actually make it into the mainline until June, 2007 (2.6.22).  What
+happened?
+
+This code showed a number of signs of having been developed behind
+corporate doors.  But one large problem in particular was that it was not
+designed to work on multiprocessor systems.  Before this networking stack
+(now called mac80211) could be merged, a locking scheme needed to be
+retrofitted onto it.  
+
+Once upon a time, Linux kernel code could be developed without thinking
+about the concurrency issues presented by multiprocessor systems.  Now,
+however, this document is being written on a dual-core laptop.  Even on
+single-processor systems, work being done to improve responsiveness will
+raise the level of concurrency within the kernel.  The days when kernel
+code could be written without thinking about locking are long past.
+
+Any resource (data structures, hardware registers, etc.) which could be
+accessed concurrently by more than one thread must be protected by a lock.
+New code should be written with this requirement in mind; retrofitting
+locking after the fact is a rather more difficult task.  Kernel developers
+should take the time to understand the available locking primitives well
+enough to pick the right tool for the job.  Code which shows a lack of
+attention to concurrency will have a difficult path into the mainline.
+
+
+* Regressions
+
+One final hazard worth mentioning is this: it can be tempting to make a
+change (which may bring big improvements) which causes something to break
+for existing users.  This kind of change is called a "regression," and
+regressions have become most unwelcome in the mainline kernel.  With few
+exceptions, changes which cause regressions will be backed out if the
+regression cannot be fixed in a timely manner.  Far better to avoid the
+regression in the first place.
+
+It is often argued that a regression can be justified if it causes things
+to work for more people than it creates problems for.  Why not make a
+change if it brings new functionality to ten systems for each one it
+breaks?  The best answer to this question was expressed by Linus in July,
+2007:
+
+	So we don't fix bugs by introducing new problems.  That way lies
+	madness, and nobody ever knows if you actually make any real
+	progress at all. Is it two steps forwards, one step back, or one
+	step forward and two steps back?
+
+(http://lwn.net/Articles/243460/).
+
+An especially unwelcome type of regression is any sort of change to the
+user-space ABI.  Once an interface has been exported to user space, it must
+be supported indefinitely.  This fact makes the creation of user-space
+interfaces particularly challenging: since they cannot be changed in
+incompatible ways, they must be done right the first time.  For this
+reason, a great deal of thought, clear documentation, and wide review for
+user-space interfaces is always required.
+
+
+
+4.2: CODE CHECKING TOOLS
+
+For now, at least, the writing of error-free code remains an ideal that few
+of us can reach.  What we can hope to do, though, is to catch and fix as
+many of those errors as possible before our code goes into the mainline
+kernel.  To that end, the kernel developers have put together an impressive
+array of tools which can catch a wide variety of obscure problems in an
+automated way.  Any problem caught by the computer is a problem which will
+not afflict a user later on, so it stands to reason that the automated
+tools should be used whenever possible.
+
+The first step is simply to heed the warnings produced by the compiler.
+Contemporary versions of gcc can detect (and warn about) a large number of
+potential errors.  Quite often, these warnings point to real problems.
+Code submitted for review should, as a rule, not produce any compiler
+warnings.  When silencing warnings, take care to understand the real cause
+and try to avoid "fixes" which make the warning go away without addressing
+its cause.
+
+Note that not all compiler warnings are enabled by default.  Build the
+kernel with "make EXTRA_CFLAGS=-W" to get the full set.
+
+The kernel provides several configuration options which turn on debugging
+features; most of these are found in the "kernel hacking" submenu.  Several
+of these options should be turned on for any kernel used for development or
+testing purposes.  In particular, you should turn on:
+
+ - ENABLE_WARN_DEPRECATED, ENABLE_MUST_CHECK, and FRAME_WARN to get an
+   extra set of warnings for problems like the use of deprecated interfaces
+   or ignoring an important return value from a function.  The output
+   generated by these warnings can be verbose, but one need not worry about
+   warnings from other parts of the kernel.
+
+ - DEBUG_OBJECTS will add code to track the lifetime of various objects
+   created by the kernel and warn when things are done out of order.  If
+   you are adding a subsystem which creates (and exports) complex objects
+   of its own, consider adding support for the object debugging
+   infrastructure.
+
+ - DEBUG_SLAB can find a variety of memory allocation and use errors; it
+   should be used on most development kernels.
+
+ - DEBUG_SPINLOCK, DEBUG_SPINLOCK_SLEEP, and DEBUG_MUTEXES will find a
+   number of common locking errors.
+
+There are quite a few other debugging options, some of which will be
+discussed below.  Some of them have a significant performance impact and
+should not be used all of the time.  But some time spent learning the
+available options will likely be paid back many times over in short order. 
+
+One of the heavier debugging tools is the locking checker, or "lockdep."
+This tool will track the acquisition and release of every lock (spinlock or
+mutex) in the system, the order in which locks are acquired relative to
+each other, the current interrupt environment, and more.  It can then
+ensure that locks are always acquired in the same order, that the same
+interrupt assumptions apply in all situations, and so on.  In other words,
+lockdep can find a number of scenarios in which the system could, on rare
+occasion, deadlock.  This kind of problem can be painful (for both
+developers and users) in a deployed system; lockdep allows them to be found
+in an automated manner ahead of time.  Code with any sort of non-trivial
+locking should be run with lockdep enabled before being submitted for
+inclusion. 
+
+As a diligent kernel programmer, you will, beyond doubt, check the return
+status of any operation (such as a memory allocation) which can fail.  The
+fact of the matter, though, is that the resulting failure recovery paths
+are, probably, completely untested.  Untested code tends to be broken code;
+you could be much more confident of your code if all those error-handling
+paths had been exercised a few times.
+
+The kernel provides a fault injection framework which can do exactly that,
+especially where memory allocations are involved.  With fault injection
+enabled, a configurable percentage of memory allocations will be made to
+fail; these failures can be restricted to a specific range of code.
+Running with fault injection enabled allows the programmer to see how the
+code responds when things go badly.  See
+Documentation/fault-injection/fault-injection.text for more information on
+how to use this facility.
+
+Other kinds of errors can be found with the "sparse" static analysis tool.
+With sparse, the programmer can be warned about confusion between
+user-space and kernel-space addresses, mixture of big-endian and
+small-endian quantities, the passing of integer values where a set of bit
+flags is expected, and so on.  Sparse must be installed separately (it can
+be found at http://www.kernel.org/pub/software/devel/sparse/ if your
+distributor does not package it); it can then be run on the code by adding
+"C=1" to your make command.
+
+Other kinds of portability errors are best found by compiling your code for
+other architectures.  If you do not happen to have an S/390 system or a
+Blackfin development board handy, you can still perform the compilation
+step.  A large set of cross compilers for x86 systems can be found at 
+
+	http://www.kernel.org/pub/tools/crosstool/
+
+Some time spent installing and using these compilers will help avoid
+embarrassment later.
+
+
+4.3: DOCUMENTATION
+
+Documentation has often been more the exception than the rule with kernel
+development.  Even so, adequate documentation will help to ease the merging
+of new code into the kernel, make life easier for other developers, and
+will be helpful for your users.  In many cases, the addition of
+documentation has become essentially mandatory.
+
+The first piece of documentation for any patch is its associated
+changelog.  Log entries should describe the problem being solved, the form
+of the solution, the people who worked on the patch, any relevant
+effects on performance, and anything else that might be needed to
+understand the patch.
+
+Any code which adds a new user-space interface - including new sysfs or
+/proc files - should include documentation of that interface which enables
+user-space developers to know what they are working with.  See
+Documentation/ABI/README for a description of how this documentation should
+be formatted and what information needs to be provided.
+
+The file Documentation/kernel-parameters.txt describes all of the kernel's
+boot-time parameters.  Any patch which adds new parameters should add the
+appropriate entries to this file.
+
+Any new configuration options must be accompanied by help text which
+clearly explains the options and when the user might want to select them. 
+
+Internal API information for many subsystems is documented by way of
+specially-formatted comments; these comments can be extracted and formatted
+in a number of ways by the "kernel-doc" script.  If you are working within
+a subsystem which has kerneldoc comments, you should maintain them and add
+them, as appropriate, for externally-available functions.  Even in areas
+which have not been so documented, there is no harm in adding kerneldoc
+comments for the future; indeed, this can be a useful activity for
+beginning kernel developers.  The format of these comments, along with some
+information on how to create kerneldoc templates can be found in the file
+Documentation/kernel-doc-nano-HOWTO.txt.
+
+Anybody who reads through a significant amount of existing kernel code will
+note that, often, comments are most notable by their absence.  Once again,
+the expectations for new code are higher than they were in the past;
+merging uncommented code will be harder.  That said, there is little desire
+for verbosely-commented code.  The code should, itself, be readable, with
+comments explaining the more subtle aspects.
+
+Certain things should always be commented.  Uses of memory barriers should
+be accompanied by a line explaining why the barrier is necessary.  The
+locking rules for data structures generally need to be explained somewhere.
+Major data structures need comprehensive documentation in general.
+Non-obvious dependencies between separate bits of code should be pointed
+out.  Anything which might tempt a code janitor to make an incorrect
+"cleanup" needs a comment saying why it is done the way it is.  And so on.
+
+
+4.4: INTERNAL API CHANGES
+
+The binary interface provided by the kernel to user space cannot be broken
+except under the most severe circumstances.  The kernel's internal
+programming interfaces, instead, are highly fluid and can be changed when
+the need arises.  If you find yourself having to work around a kernel API,
+or simply not using a specific functionality because it does not meet your
+needs, that may be a sign that the API needs to change.  As a kernel
+developer, you are empowered to make such changes.
+
+There are, of course, some catches.  API changes can be made, but they need
+to be well justified.  So any patch making an internal API change should be
+accompanied by a description of what the change is and why it is
+necessary.  This kind of change should also be broken out into a separate
+patch, rather than buried within a larger patch.
+
+The other catch is that a developer who changes an internal API is
+generally charged with the task of fixing any code within the kernel tree
+which is broken by the change.  For a widely-used function, this duty can
+lead to literally hundreds or thousands of changes - many of which are
+likely to conflict with work being done by other developers.  Needless to
+say, this can be a large job, so it is best to be sure that the
+justification is solid.
+
+When making an incompatible API change, one should, whenever possible,
+ensure that code which has not been updated is caught by the compiler.  
+This will help you to be sure that you have found all in-tree uses of that
+interface.  It will also alert developers of out-of-tree code that there is
+a change that they need to respond to.  Supporting out-of-tree code is not
+something that kernel developers need to be worried about, but we also do
+not have to make life harder for out-of-tree developers than it it needs to
+be. 

Documentation/development-process/5.Posting

@@ -0,0 +1,278 @@
+5: POSTING PATCHES
+
+Sooner or later, the time comes when your work is ready to be presented to
+the community for review and, eventually, inclusion into the mainline
+kernel.  Unsurprisingly, the kernel development community has evolved a set
+of conventions and procedures which are used in the posting of patches;
+following them will make life much easier for everybody involved.  This
+document will attempt to cover these expectations in reasonable detail;
+more information can also be found in the files SubmittingPatches,
+SubmittingDrivers, and SubmitChecklist in the kernel documentation
+directory.
+
+
+5.1: WHEN TO POST
+
+There is a constant temptation to avoid posting patches before they are
+completely "ready."  For simple patches, that is not a problem.  If the
+work being done is complex, though, there is a lot to be gained by getting
+feedback from the community before the work is complete.  So you should
+consider posting in-progress work, or even making a git tree available so
+that interested developers can catch up with your work at any time.
+
+When posting code which is not yet considered ready for inclusion, it is a
+good idea to say so in the posting itself.  Also mention any major work
+which remains to be done and any known problems.  Fewer people will look at
+patches which are known to be half-baked, but those who do will come in
+with the idea that they can help you drive the work in the right direction.
+
+
+5.2: BEFORE CREATING PATCHES
+
+There are a number of things which should be done before you consider
+sending patches to the development community.  These include:
+
+ - Test the code to the extent that you can.  Make use of the kernel's
+   debugging tools, ensure that the kernel will build with all reasonable
+   combinations of configuration options, use cross-compilers to build for
+   different architectures, etc.
+
+ - Make sure your code is compliant with the kernel coding style
+   guidelines.
+
+ - Does your change have performance implications?  If so, you should run
+   benchmarks showing what the impact (or benefit) of your change is; a
+   summary of the results should be included with the patch.
+
+ - Be sure that you have the right to post the code.  If this work was done
+   for an employer, the employer likely has a right to the work and must be
+   agreeable with its release under the GPL.
+
+As a general rule, putting in some extra thought before posting code almost
+always pays back the effort in short order.
+
+
+5.3: PATCH PREPARATION
+
+The preparation of patches for posting can be a surprising amount of work,
+but, once again, attempting to save time here is not generally advisable
+even in the short term.
+
+Patches must be prepared against a specific version of the kernel.  As a
+general rule, a patch should be based on the current mainline as found in
+Linus's git tree.  It may become necessary to make versions against -mm,
+linux-next, or a subsystem tree, though, to facilitate wider testing and
+review.  Depending on the area of your patch and what is going on
+elsewhere, basing a patch against these other trees can require a
+significant amount of work resolving conflicts and dealing with API
+changes.
+
+Only the most simple changes should be formatted as a single patch;
+everything else should be made as a logical series of changes.  Splitting
+up patches is a bit of an art; some developers spend a long time figuring
+out how to do it in the way that the community expects.  There are a few
+rules of thumb, however, which can help considerably:
+
+ - The patch series you post will almost certainly not be the series of
+   changes found in your working revision control system.  Instead, the
+   changes you have made need to be considered in their final form, then
+   split apart in ways which make sense.  The developers are interested in
+   discrete, self-contained changes, not the path you took to get to those
+   changes.
+
+ - Each logically independent change should be formatted as a separate
+   patch.  These changes can be small ("add a field to this structure") or
+   large (adding a significant new driver, for example), but they should be
+   conceptually small and amenable to a one-line description.  Each patch
+   should make a specific change which can be reviewed on its own and
+   verified to do what it says it does.
+
+ - As a way of restating the guideline above: do not mix different types of
+   changes in the same patch.  If a single patch fixes a critical security
+   bug, rearranges a few structures, and reformats the code, there is a
+   good chance that it will be passed over and the important fix will be
+   lost.
+
+ - Each patch should yield a kernel which builds and runs properly; if your
+   patch series is interrupted in the middle, the result should still be a
+   working kernel.  Partial application of a patch series is a common
+   scenario when the "git bisect" tool is used to find regressions; if the
+   result is a broken kernel, you will make life harder for developers and
+   users who are engaging in the noble work of tracking down problems.
+
+ - Do not overdo it, though.  One developer recently posted a set of edits
+   to a single file as 500 separate patches - an act which did not make him
+   the most popular person on the kernel mailing list.  A single patch can
+   be reasonably large as long as it still contains a single *logical*
+   change. 
+
+ - It can be tempting to add a whole new infrastructure with a series of
+   patches, but to leave that infrastructure unused until the final patch
+   in the series enables the whole thing.  This temptation should be
+   avoided if possible; if that series adds regressions, bisection will
+   finger the last patch as the one which caused the problem, even though
+   the real bug is elsewhere.  Whenever possible, a patch which adds new
+   code should make that code active immediately.
+
+Working to create the perfect patch series can be a frustrating process
+which takes quite a bit of time and thought after the "real work" has been
+done.  When done properly, though, it is time well spent.
+
+
+5.4: PATCH FORMATTING
+
+So now you have a perfect series of patches for posting, but the work is
+not done quite yet.  Each patch needs to be formatted into a message which
+quickly and clearly communicates its purpose to the rest of the world.  To
+that end, each patch will be composed of the following:
+
+ - An optional "From" line naming the author of the patch.  This line is
+   only necessary if you are passing on somebody else's patch via email,
+   but it never hurts to add it when in doubt.
+
+ - A one-line description of what the patch does.  This message should be
+   enough for a reader who sees it with no other context to figure out the
+   scope of the patch; it is the line that will show up in the "short form"
+   changelogs.  This message is usually formatted with the relevant
+   subsystem name first, followed by the purpose of the patch.  For
+   example:
+
+	gpio: fix build on CONFIG_GPIO_SYSFS=n
+
+ - A blank line followed by a detailed description of the contents of the
+   patch.  This description can be as long as is required; it should say
+   what the patch does and why it should be applied to the kernel.
+
+ - One or more tag lines, with, at a minimum, one Signed-off-by: line from
+   the author of the patch.  Tags will be described in more detail below.
+
+The above three items should, normally, be the text used when committing
+the change to a revision control system.  They are followed by:
+
+ - The patch itself, in the unified ("-u") patch format.  Using the "-p"
+   option to diff will associate function names with changes, making the
+   resulting patch easier for others to read.
+
+You should avoid including changes to irrelevant files (those generated by
+the build process, for example, or editor backup files) in the patch.  The
+file "dontdiff" in the Documentation directory can help in this regard;
+pass it to diff with the "-X" option.
+
+The tags mentioned above are used to describe how various developers have
+been associated with the development of this patch.  They are described in
+detail in the SubmittingPatches document; what follows here is a brief
+summary.  Each of these lines has the format:
+
+	tag: Full Name <email address>  optional-other-stuff
+
+The tags in common use are:
+
+ - Signed-off-by: this is a developer's certification that he or she has
+   the right to submit the patch for inclusion into the kernel.  It is an
+   agreement to the Developer's Certificate of Origin, the full text of
+   which can be found in Documentation/SubmittingPatches.  Code without a
+   proper signoff cannot be merged into the mainline.
+
+ - Acked-by: indicates an agreement by another developer (often a
+   maintainer of the relevant code) that the patch is appropriate for
+   inclusion into the kernel.
+
+ - Tested-by: states that the named person has tested the patch and found
+   it to work.
+
+ - Reviewed-by: the named developer has reviewed the patch for correctness;
+   see the reviewer's statement in Documentation/SubmittingPatches for more
+   detail.
+
+ - Reported-by: names a user who reported a problem which is fixed by this
+   patch; this tag is used to give credit to the (often underappreciated)
+   people who test our code and let us know when things do not work
+   correctly.
+
+ - Cc: the named person received a copy of the patch and had the
+   opportunity to comment on it.
+
+Be careful in the addition of tags to your patches: only Cc: is appropriate
+for addition without the explicit permission of the person named.
+
+
+5.5: SENDING THE PATCH
+
+Before you mail your patches, there are a couple of other things you should
+take care of:
+
+ - Are you sure that your mailer will not corrupt the patches?  Patches
+   which have had gratuitous white-space changes or line wrapping performed
+   by the mail client will not apply at the other end, and often will not
+   be examined in any detail.  If there is any doubt at all, mail the patch
+   to yourself and convince yourself that it shows up intact.  
+
+   Documentation/email-clients.txt has some helpful hints on making
+   specific mail clients work for sending patches.
+
+ - Are you sure your patch is free of silly mistakes?  You should always
+   run patches through scripts/checkpatch.pl and address the complaints it
+   comes up with.  Please bear in mind that checkpatch.pl, while being the
+   embodiment of a fair amount of thought about what kernel patches should
+   look like, is not smarter than you.  If fixing a checkpatch.pl complaint
+   would make the code worse, don't do it.
+
+Patches should always be sent as plain text.  Please do not send them as
+attachments; that makes it much harder for reviewers to quote sections of
+the patch in their replies.  Instead, just put the patch directly into your
+message.
+
+When mailing patches, it is important to send copies to anybody who might
+be interested in it.  Unlike some other projects, the kernel encourages
+people to err on the side of sending too many copies; don't assume that the
+relevant people will see your posting on the mailing lists.  In particular,
+copies should go to:
+
+ - The maintainer(s) of the affected subsystem(s).  As described earlier,
+   the MAINTAINERS file is the first place to look for these people.
+
+ - Other developers who have been working in the same area - especially
+   those who might be working there now.  Using git to see who else has
+   modified the files you are working on can be helpful.
+
+ - If you are responding to a bug report or a feature request, copy the
+   original poster as well.
+
+ - Send a copy to the relevant mailing list, or, if nothing else applies,
+   the linux-kernel list.
+
+ - If you are fixing a bug, think about whether the fix should go into the
+   next stable update.  If so, stable@kernel.org should get a copy of the
+   patch.  Also add a "Cc: stable@kernel.org" to the tags within the patch
+   itself; that will cause the stable team to get a notification when your
+   fix goes into the mainline.
+
+When selecting recipients for a patch, it is good to have an idea of who
+you think will eventually accept the patch and get it merged.  While it
+is possible to send patches directly to Linus Torvalds and have him merge
+them, things are not normally done that way.  Linus is busy, and there are
+subsystem maintainers who watch over specific parts of the kernel.  Usually
+you will be wanting that maintainer to merge your patches.  If there is no
+obvious maintainer, Andrew Morton is often the patch target of last resort.
+
+Patches need good subject lines.  The canonical format for a patch line is
+something like:
+
+	[PATCH nn/mm] subsys: one-line description of the patch
+
+where "nn" is the ordinal number of the patch, "mm" is the total number of
+patches in the series, and "subsys" is the name of the affected subsystem.
+Clearly, nn/mm can be omitted for a single, standalone patch.  
+
+If you have a significant series of patches, it is customary to send an
+introductory description as part zero.  This convention is not universally
+followed though; if you use it, remember that information in the
+introduction does not make it into the kernel changelogs.  So please ensure
+that the patches, themselves, have complete changelog information.
+
+In general, the second and following parts of a multi-part patch should be
+sent as a reply to the first part so that they all thread together at the
+receiving end.  Tools like git and quilt have commands to mail out a set of
+patches with the proper threading.  If you have a long series, though, and
+are using git, please provide the --no-chain-reply-to option to avoid
+creating exceptionally deep nesting.

Documentation/development-process/6.Followthrough

@@ -0,0 +1,202 @@
+6: FOLLOWTHROUGH
+
+At this point, you have followed the guidelines given so far and, with the
+addition of your own engineering skills, have posted a perfect series of
+patches.  One of the biggest mistakes that even experienced kernel
+developers can make is to conclude that their work is now done.  In truth,
+posting patches indicates a transition into the next stage of the process,
+with, possibly, quite a bit of work yet to be done.
+
+It is a rare patch which is so good at its first posting that there is no
+room for improvement.  The kernel development process recognizes this fact,
+and, as a result, is heavily oriented toward the improvement of posted
+code.  You, as the author of that code, will be expected to work with the
+kernel community to ensure that your code is up to the kernel's quality
+standards.  A failure to participate in this process is quite likely to
+prevent the inclusion of your patches into the mainline.
+
+
+6.1: WORKING WITH REVIEWERS
+
+A patch of any significance will result in a number of comments from other
+developers as they review the code.  Working with reviewers can be, for
+many developers, the most intimidating part of the kernel development
+process.  Life can be made much easier, though, if you keep a few things in
+mind:
+
+ - If you have explained your patch well, reviewers will understand its
+   value and why you went to the trouble of writing it.  But that value
+   will not keep them from asking a fundamental question: what will it be
+   like to maintain a kernel with this code in it five or ten years later?
+   Many of the changes you may be asked to make - from coding style tweaks
+   to substantial rewrites - come from the understanding that Linux will
+   still be around and under development a decade from now.
+
+ - Code review is hard work, and it is a relatively thankless occupation;
+   people remember who wrote kernel code, but there is little lasting fame
+   for those who reviewed it.  So reviewers can get grumpy, especially when
+   they see the same mistakes being made over and over again.  If you get a
+   review which seems angry, insulting, or outright offensive, resist the
+   impulse to respond in kind.  Code review is about the code, not about
+   the people, and code reviewers are not attacking you personally.
+
+ - Similarly, code reviewers are not trying to promote their employers'
+   agendas at the expense of your own.  Kernel developers often expect to
+   be working on the kernel years from now, but they understand that their
+   employer could change.  They truly are, almost without exception,
+   working toward the creation of the best kernel they can; they are not
+   trying to create discomfort for their employers' competitors.
+
+What all of this comes down to is that, when reviewers send you comments,
+you need to pay attention to the technical observations that they are
+making.  Do not let their form of expression or your own pride keep that
+from happening.  When you get review comments on a patch, take the time to
+understand what the reviewer is trying to say.  If possible, fix the things
+that the reviewer is asking you to fix.  And respond back to the reviewer:
+thank them, and describe how you will answer their questions.
+
+Note that you do not have to agree with every change suggested by
+reviewers.  If you believe that the reviewer has misunderstood your code,
+explain what is really going on.  If you have a technical objection to a
+suggested change, describe it and justify your solution to the problem.  If
+your explanations make sense, the reviewer will accept them.  Should your
+explanation not prove persuasive, though, especially if others start to
+agree with the reviewer, take some time to think things over again.  It can
+be easy to become blinded by your own solution to a problem to the point
+that you don't realize that something is fundamentally wrong or, perhaps,
+you're not even solving the right problem.
+
+One fatal mistake is to ignore review comments in the hope that they will
+go away.  They will not go away.  If you repost code without having
+responded to the comments you got the time before, you're likely to find
+that your patches go nowhere.
+
+Speaking of reposting code: please bear in mind that reviewers are not
+going to remember all the details of the code you posted the last time
+around.  So it is always a good idea to remind reviewers of previously
+raised issues and how you dealt with them; the patch changelog is a good
+place for this kind of information.  Reviewers should not have to search
+through list archives to familiarize themselves with what was said last
+time; if you help them get a running start, they will be in a better mood
+when they revisit your code.
+
+What if you've tried to do everything right and things still aren't going
+anywhere?  Most technical disagreements can be resolved through discussion,
+but there are times when somebody simply has to make a decision.  If you
+honestly believe that this decision is going against you wrongly, you can
+always try appealing to a higher power.  As of this writing, that higher
+power tends to be Andrew Morton.  Andrew has a great deal of respect in the
+kernel development community; he can often unjam a situation which seems to
+be hopelessly blocked.  Appealing to Andrew should not be done lightly,
+though, and not before all other alternatives have been explored.  And bear
+in mind, of course, that he may not agree with you either.
+
+
+6.2: WHAT HAPPENS NEXT
+
+If a patch is considered to be a good thing to add to the kernel, and once
+most of the review issues have been resolved, the next step is usually
+entry into a subsystem maintainer's tree.  How that works varies from one
+subsystem to the next; each maintainer has his or her own way of doing
+things.  In particular, there may be more than one tree - one, perhaps,
+dedicated to patches planned for the next merge window, and another for
+longer-term work.  
+
+For patches applying to areas for which there is no obvious subsystem tree
+(memory management patches, for example), the default tree often ends up
+being -mm.  Patches which affect multiple subsystems can also end up going
+through the -mm tree.
+
+Inclusion into a subsystem tree can bring a higher level of visibility to a
+patch.  Now other developers working with that tree will get the patch by
+default.  Subsystem trees typically feed into -mm and linux-next as well,
+making their contents visible to the development community as a whole.  At
+this point, there's a good chance that you will get more comments from a
+new set of reviewers; these comments need to be answered as in the previous
+round.
+
+What may also happen at this point, depending on the nature of your patch,
+is that conflicts with work being done by others turn up.  In the worst
+case, heavy patch conflicts can result in some work being put on the back
+burner so that the remaining patches can be worked into shape and merged.
+Other times, conflict resolution will involve working with the other
+developers and, possibly, moving some patches between trees to ensure that
+everything applies cleanly.  This work can be a pain, but count your
+blessings: before the advent of the linux-next tree, these conflicts often
+only turned up during the merge window and had to be addressed in a hurry.
+Now they can be resolved at leisure, before the merge window opens.
+
+Some day, if all goes well, you'll log on and see that your patch has been
+merged into the mainline kernel.  Congratulations!  Once the celebration is
+complete (and you have added yourself to the MAINTAINERS file), though, it
+is worth remembering an important little fact: the job still is not done.
+Merging into the mainline brings its own challenges.
+
+To begin with, the visibility of your patch has increased yet again.  There
+may be a new round of comments from developers who had not been aware of
+the patch before.  It may be tempting to ignore them, since there is no
+longer any question of your code being merged.  Resist that temptation,
+though; you still need to be responsive to developers who have questions or
+suggestions.
+
+More importantly, though: inclusion into the mainline puts your code into
+the hands of a much larger group of testers.  Even if you have contributed
+a driver for hardware which is not yet available, you will be surprised by
+how many people will build your code into their kernels.  And, of course,
+where there are testers, there will be bug reports.
+
+The worst sort of bug reports are regressions.  If your patch causes a
+regression, you'll find an uncomfortable number of eyes upon you;
+regressions need to be fixed as soon as possible.  If you are unwilling or
+unable to fix the regression (and nobody else does it for you), your patch
+will almost certainly be removed during the stabilization period.  Beyond
+negating all of the work you have done to get your patch into the mainline,
+having a patch pulled as the result of a failure to fix a regression could
+well make it harder for you to get work merged in the future.
+
+After any regressions have been dealt with, there may be other, ordinary
+bugs to deal with.  The stabilization period is your best opportunity to
+fix these bugs and ensure that your code's debut in a mainline kernel
+release is as solid as possible.  So, please, answer bug reports, and fix
+the problems if at all possible.  That's what the stabilization period is
+for; you can start creating cool new patches once any problems with the old
+ones have been taken care of.
+
+And don't forget that there are other milestones which may also create bug
+reports: the next mainline stable release, when prominent distributors pick
+up a version of the kernel containing your patch, etc.  Continuing to
+respond to these reports is a matter of basic pride in your work.  If that
+is insufficient motivation, though, it's also worth considering that the
+development community remembers developers who lose interest in their code
+after it's merged.  The next time you post a patch, they will be evaluating
+it with the assumption that you will not be around to maintain it
+afterward.
+
+
+6.3: OTHER THINGS THAT CAN HAPPEN
+
+One day, you may open your mail client and see that somebody has mailed you
+a patch to your code.  That is one of the advantages of having your code
+out there in the open, after all.  If you agree with the patch, you can
+either forward it on to the subsystem maintainer (be sure to include a
+proper From: line so that the attribution is correct, and add a signoff of
+your own), or send an Acked-by: response back and let the original poster
+send it upward.
+
+If you disagree with the patch, send a polite response explaining why.  If
+possible, tell the author what changes need to be made to make the patch
+acceptable to you.  There is a certain resistance to merging patches which
+are opposed by the author and maintainer of the code, but it only goes so
+far.  If you are seen as needlessly blocking good work, those patches will
+eventually flow around you and get into the mainline anyway.  In the Linux
+kernel, nobody has absolute veto power over any code.  Except maybe Linus.
+
+On very rare occasion, you may see something completely different: another
+developer posts a different solution to your problem.  At that point,
+chances are that one of the two patches will not be merged, and "mine was
+here first" is not considered to be a compelling technical argument.  If
+somebody else's patch displaces yours and gets into the mainline, there is
+really only one way to respond: be pleased that your problem got solved and
+get on with your work.  Having one's work shoved aside in this manner can
+be hurtful and discouraging, but the community will remember your reaction
+long after they have forgotten whose patch actually got merged.

Documentation/development-process/7.AdvancedTopics

@@ -0,0 +1,173 @@
+7: ADVANCED TOPICS
+
+At this point, hopefully, you have a handle on how the development process
+works.  There is still more to learn, however!  This section will cover a
+number of topics which can be helpful for developers wanting to become a
+regular part of the Linux kernel development process.
+
+7.1: MANAGING PATCHES WITH GIT
+
+The use of distributed version control for the kernel began in early 2002,
+when Linus first started playing with the proprietary BitKeeper
+application.  While BitKeeper was controversial, the approach to software
+version management it embodied most certainly was not.  Distributed version
+control enabled an immediate acceleration of the kernel development
+project.  In current times, there are several free alternatives to
+BitKeeper.  For better or for worse, the kernel project has settled on git
+as its tool of choice.
+
+Managing patches with git can make life much easier for the developer,
+especially as the volume of those patches grows.  Git also has its rough
+edges and poses certain hazards; it is a young and powerful tool which is
+still being civilized by its developers.  This document will not attempt to
+teach the reader how to use git; that would be sufficient material for a
+long document in its own right.  Instead, the focus here will be on how git
+fits into the kernel development process in particular.  Developers who
+wish to come up to speed with git will find more information at:
+
+	http://git.or.cz/
+
+	http://www.kernel.org/pub/software/scm/git/docs/user-manual.html
+
+and on various tutorials found on the web.
+
+The first order of business is to read the above sites and get a solid
+understanding of how git works before trying to use it to make patches
+available to others.  A git-using developer should be able to obtain a copy
+of the mainline repository, explore the revision history, commit changes to
+the tree, use branches, etc.  An understanding of git's tools for the
+rewriting of history (such as rebase) is also useful.  Git comes with its
+own terminology and concepts; a new user of git should know about refs,
+remote branches, the index, fast-forward merges, pushes and pulls, detached
+heads, etc.  It can all be a little intimidating at the outset, but the
+concepts are not that hard to grasp with a bit of study.
+
+Using git to generate patches for submission by email can be a good
+exercise while coming up to speed.
+
+When you are ready to start putting up git trees for others to look at, you
+will, of course, need a server that can be pulled from.  Setting up such a
+server with git-daemon is relatively straightforward if you have a system
+which is accessible to the Internet.  Otherwise, free, public hosting sites
+(Github, for example) are starting to appear on the net.  Established
+developers can get an account on kernel.org, but those are not easy to come
+by; see http://kernel.org/faq/ for more information.
+
+The normal git workflow involves the use of a lot of branches.  Each line
+of development can be separated into a separate "topic branch" and
+maintained independently.  Branches in git are cheap, there is no reason to
+not make free use of them.  And, in any case, you should not do your
+development in any branch which you intend to ask others to pull from.
+Publicly-available branches should be created with care; merge in patches
+from development branches when they are in complete form and ready to go -
+not before.
+
+Git provides some powerful tools which can allow you to rewrite your
+development history.  An inconvenient patch (one which breaks bisection,
+say, or which has some other sort of obvious bug) can be fixed in place or
+made to disappear from the history entirely.  A patch series can be
+rewritten as if it had been written on top of today's mainline, even though
+you have been working on it for months.  Changes can be transparently
+shifted from one branch to another.  And so on.  Judicious use of git's
+ability to revise history can help in the creation of clean patch sets with
+fewer problems.
+
+Excessive use of this capability can lead to other problems, though, beyond
+a simple obsession for the creation of the perfect project history.
+Rewriting history will rewrite the changes contained in that history,
+turning a tested (hopefully) kernel tree into an untested one.  But, beyond
+that, developers cannot easily collaborate if they do not have a shared
+view of the project history; if you rewrite history which other developers
+have pulled into their repositories, you will make life much more difficult
+for those developers.  So a simple rule of thumb applies here: history
+which has been exported to others should generally be seen as immutable
+thereafter.
+
+So, once you push a set of changes to your publicly-available server, those
+changes should not be rewritten.  Git will attempt to enforce this rule if
+you try to push changes which do not result in a fast-forward merge
+(i.e. changes which do not share the same history).  It is possible to
+override this check, and there may be times when it is necessary to rewrite
+an exported tree.  Moving changesets between trees to avoid conflicts in
+linux-next is one example.  But such actions should be rare.  This is one
+of the reasons why development should be done in private branches (which
+can be rewritten if necessary) and only moved into public branches when
+it's in a reasonably advanced state.
+
+As the mainline (or other tree upon which a set of changes is based)
+advances, it is tempting to merge with that tree to stay on the leading
+edge.  For a private branch, rebasing can be an easy way to keep up with
+another tree, but rebasing is not an option once a tree is exported to the
+world.  Once that happens, a full merge must be done.  Merging occasionally
+makes good sense, but overly frequent merges can clutter the history
+needlessly.  Suggested technique in this case is to merge infrequently, and
+generally only at specific release points (such as a mainline -rc
+release).  If you are nervous about specific changes, you can always
+perform test merges in a private branch.  The git "rerere" tool can be
+useful in such situations; it remembers how merge conflicts were resolved
+so that you don't have to do the same work twice.
+
+One of the biggest recurring complaints about tools like git is this: the
+mass movement of patches from one repository to another makes it easy to
+slip in ill-advised changes which go into the mainline below the review
+radar.  Kernel developers tend to get unhappy when they see that kind of
+thing happening; putting up a git tree with unreviewed or off-topic patches
+can affect your ability to get trees pulled in the future.  Quoting Linus:
+
+	You can send me patches, but for me to pull a git patch from you, I
+	need to know that you know what you're doing, and I need to be able
+	to trust things *without* then having to go and check every
+	individual change by hand.
+
+(http://lwn.net/Articles/224135/).  
+
+To avoid this kind of situation, ensure that all patches within a given
+branch stick closely to the associated topic; a "driver fixes" branch
+should not be making changes to the core memory management code.  And, most
+importantly, do not use a git tree to bypass the review process.  Post an
+occasional summary of the tree to the relevant list, and, when the time is
+right, request that the tree be included in linux-next.
+
+If and when others start to send patches for inclusion into your tree,
+don't forget to review them.  Also ensure that you maintain the correct
+authorship information; the git "am" tool does its best in this regard, but
+you may have to add a "From:" line to the patch if it has been relayed to
+you via a third party.
+
+When requesting a pull, be sure to give all the relevant information: where
+your tree is, what branch to pull, and what changes will result from the
+pull.  The git request-pull command can be helpful in this regard; it will
+format the request as other developers expect, and will also check to be
+sure that you have remembered to push those changes to the public server. 
+
+
+7.2: REVIEWING PATCHES
+
+Some readers will certainly object to putting this section with "advanced
+topics" on the grounds that even beginning kernel developers should be
+reviewing patches.  It is certainly true that there is no better way to
+learn how to program in the kernel environment than by looking at code
+posted by others.  In addition, reviewers are forever in short supply; by
+looking at code you can make a significant contribution to the process as a
+whole.
+
+Reviewing code can be an intimidating prospect, especially for a new kernel
+developer who may well feel nervous about questioning code - in public -
+which has been posted by those with more experience.  Even code written by
+the most experienced developers can be improved, though.  Perhaps the best
+piece of advice for reviewers (all reviewers) is this: phrase review
+comments as questions rather than criticisms.  Asking "how does the lock
+get released in this path?" will always work better than stating "the
+locking here is wrong."
+
+Different developers will review code from different points of view.  Some
+are mostly concerned with coding style and whether code lines have trailing
+white space.  Others will focus primarily on whether the change implemented
+by the patch as a whole is a good thing for the kernel or not.  Yet others
+will check for problematic locking, excessive stack usage, possible
+security issues, duplication of code found elsewhere, adequate
+documentation, adverse effects on performance, user-space ABI changes, etc.
+All types of review, if they lead to better code going into the kernel, are
+welcome and worthwhile.
+
+

Documentation/development-process/8.Conclusion

@@ -0,0 +1,74 @@
+8: FOR MORE INFORMATION
+
+There are numerous sources of information on Linux kernel development and
+related topics.  First among those will always be the Documentation
+directory found in the kernel source distribution.  The top-level HOWTO
+file is an important starting point; SubmittingPatches and
+SubmittingDrivers are also something which all kernel developers should
+read.  Many internal kernel APIs are documented using the kerneldoc
+mechanism; "make htmldocs" or "make pdfdocs" can be used to generate those
+documents in HTML or PDF format (though the version of TeX shipped by some
+distributions runs into internal limits and fails to process the documents
+properly).
+
+Various web sites discuss kernel development at all levels of detail.  Your
+author would like to humbly suggest http://lwn.net/ as a source;
+information on many specific kernel topics can be found via the LWN kernel
+index at:
+
+	http://lwn.net/Kernel/Index/
+
+Beyond that, a valuable resource for kernel developers is:
+
+	http://kernelnewbies.org/
+
+Information about the linux-next tree gathers at:
+
+	http://linux.f-seidel.de/linux-next/pmwiki/
+
+And, of course, one should not forget http://kernel.org/, the definitive
+location for kernel release information.
+
+There are a number of books on kernel development:
+
+	Linux Device Drivers, 3rd Edition (Jonathan Corbet, Alessandro
+	Rubini, and Greg Kroah-Hartman).  Online at
+	http://lwn.net/Kernel/LDD3/.
+
+	Linux Kernel Development (Robert Love).
+
+	Understanding the Linux Kernel (Daniel Bovet and Marco Cesati).
+
+All of these books suffer from a common fault, though: they tend to be
+somewhat obsolete by the time they hit the shelves, and they have been on
+the shelves for a while now.  Still, there is quite a bit of good
+information to be found there.
+
+Documentation for git can be found at:
+
+	http://www.kernel.org/pub/software/scm/git/docs/
+
+	http://www.kernel.org/pub/software/scm/git/docs/user-manual.html
+
+
+9: CONCLUSION
+
+Congratulations to anybody who has made it through this long-winded
+document.  Hopefully it has provided a helpful understanding of how the
+Linux kernel is developed and how you can participate in that process.
+
+In the end, it's the participation that matters.  Any open source software
+project is no more than the sum of what its contributors put into it.  The
+Linux kernel has progressed as quickly and as well as it has because it has
+been helped by an impressively large group of developers, all of whom are
+working to make it better.  The kernel is a premier example of what can be
+done when thousands of people work together toward a common goal.
+
+The kernel can always benefit from a larger developer base, though.  There
+is always more work to do.  But, just as importantly, most other
+participants in the Linux ecosystem can benefit through contributing to the
+kernel.  Getting code into the mainline is the key to higher code quality,
+lower maintenance and distribution costs, a higher level of influence over
+the direction of kernel development, and more.  It is a situation where
+everybody involved wins.  Fire up your editor and come join us; you will be
+more than welcome.

Documentation/devices.txt

@@ -2571,6 +2571,9 @@ Your cooperation is appreciated.
 		160 = /dev/usb/legousbtower0	1st USB Legotower device
 		    ...
 		175 = /dev/usb/legousbtower15	16th USB Legotower device
+		176 = /dev/usb/usbtmc1	First USB TMC device
+		   ...
+		192 = /dev/usb/usbtmc16	16th USB TMC device
 		240 = /dev/usb/dabusb0	First daubusb device
 		    ...
 		243 = /dev/usb/dabusb3	Fourth dabusb device

Documentation/dontdiff

@@ -2,11 +2,13 @@
 *.aux
 *.bin
 *.cpio
-*.css
+*.csp
+*.dsp
 *.dvi
+*.elf
 *.eps
-*.fw.gen.S
 *.fw
+*.gen.S
 *.gif
 *.grep
 *.grp
@@ -30,6 +32,7 @@
 *.s
 *.sgml
 *.so
+*.so.dbg
 *.symtypes
 *.tab.c
 *.tab.h
@@ -38,24 +41,17 @@
 *.xml
 *_MODULES
 *_vga16.c
-*cscope*
 *~
 *.9
 *.9.gz
 .*
-.cscope
-.gitignore
-.mailmap
 .mm
 53c700_d.h
-53c8xx_d.h*
-COPYING
-CREDITS
 CVS
 ChangeSet
 Image
 Kerntypes
-MODS.txt
+Module.markers
 Module.symvers
 PENDING
 SCCS
@@ -73,7 +69,9 @@ autoconf.h*
 bbootsect
 bin2c
 binkernel.spec
+binoffset
 bootsect
+bounds.h
 bsetup
 btfixupprep
 build
@@ -89,39 +87,36 @@ config_data.h*
 config_data.gz*
 conmakehash
 consolemap_deftbl.c*
+cpustr.h
 crc32table.h*
 cscope.*
-defkeymap.c*
+defkeymap.c
 devlist.h*
 docproc
-dummy_sym.c*
 elf2ecoff
 elfconfig.h*
-filelist
 fixdep
 fore200e_mkfirm
 fore200e_pca_fw.c*
 gconf
 gen-devlist
-gen-kdb_cmds.c*
 gen_crc32table
 gen_init_cpio
 genksyms
-gentbl
 *_gray256.c
+ihex2fw
 ikconfig.h*
 initramfs_data.cpio
 initramfs_data.cpio.gz
 initramfs_list
 kallsyms
 kconfig
-kconfig.tk
-keywords.c*
+keywords.c
 ksym.c*
 ksym.h*
 kxgettext
 lkc_defs.h
-lex.c*
+lex.c
 lex.*.c
 logo_*.c
 logo_*_clut224.c
@@ -130,7 +125,6 @@ lxdialog
 mach-types
 mach-types.h
 machtypes.h
-make_times_h
 map
 maui_boot.h
 mconf
@@ -138,6 +132,7 @@ miboot*
 mk_elfconfig
 mkboot
 mkbugboot
+mkcpustr
 mkdep
 mkprep
 mktables
@@ -145,11 +140,12 @@ mktree
 modpost
 modules.order
 modversions.h*
+ncscope.*
 offset.h
 offsets.h
 oui.c*
-parse.c*
-parse.h*
+parse.c
+parse.h
 patches*
 pca200e.bin
 pca200e_ecd.bin2
@@ -157,7 +153,7 @@ piggy.gz
 piggyback
 pnmtologo
 ppc_defs.h*
-promcon_tbl.c*
+promcon_tbl.c
 pss_boot.h
 qconf
 raid6altivec*.c
@@ -168,27 +164,38 @@ series
 setup
 setup.bin
 setup.elf
-sim710_d.h*
 sImage
 sm_tbl*
 split-include
+syscalltab.h
 tags
 tftpboot.img
 timeconst.h
 times.h*
-tkparse
 trix_boot.h
 utsrelease.h*
+vdso-syms.lds
 vdso.lds
+vdso32-int80-syms.lds
+vdso32-syms.lds
+vdso32-syscall-syms.lds
+vdso32-sysenter-syms.lds
+vdso32.lds
+vdso32.so.dbg
+vdso64.lds
+vdso64.so.dbg
 version.h*
 vmlinux
 vmlinux-*
 vmlinux.aout
-vmlinux*.lds*
-vmlinux*.scr
+vmlinux.lds
 vsyscall.lds
+vsyscall_32.lds
 wanxlfw.inc
 uImage
 unifdef
+wakeup.bin
+wakeup.elf
+wakeup.lds
 zImage*
 zconf.hash.c

Documentation/dvb/technisat.txt

@@ -0,0 +1,69 @@
+How to set up the Technisat devices
+===================================
+
+1) Find out what device you have
+================================
+
+First start your linux box with a shipped kernel:
+lspci -vvv for a PCI device (lsusb -vvv for an USB device) will show you for example:
+02:0b.0 Network controller: Techsan Electronics Co Ltd B2C2 FlexCopII DVB chip / Technisat SkyStar2 DVB card (rev 02)
+
+dmesg | grep frontend may show you for example:
+DVB: registering frontend 0 (Conexant CX24123/CX24109)...
+
+2) Kernel compilation:
+======================
+
+If the Technisat is the only TV device in your box get rid of unnecessary modules and check this one:
+"Multimedia devices" => "Customise analog and hybrid tuner modules to build"
+In this directory uncheck every driver which is activated there.
+
+Then please activate:
+2a) Main module part:
+
+a.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters"
+b.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" => "Technisat/B2C2 Air/Sky/Cable2PC PCI" in case of a PCI card OR
+c.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" => "Technisat/B2C2 Air/Sky/Cable2PC USB" in case of an USB 1.1 adapter
+d.)"Multimedia devices" => "DVB/ATSC adapters" => "Technisat/B2C2 FlexcopII(b) and FlexCopIII adapters" => "Enable debug for the B2C2 FlexCop drivers"
+Notice: d.) is helpful for troubleshooting
+
+2b) Frontend module part:
+
+1.) Revision 2.3:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "Zarlink VP310/MT312/ZL10313 based"
+
+2.) Revision 2.6:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "ST STV0299 based"
+
+3.) Revision 2.7:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "Samsung S5H1420 based"
+c.)"Multimedia devices" => "Customise DVB frontends" => "Integrant ITD1000 Zero IF tuner for DVB-S/DSS"
+d.)"Multimedia devices" => "Customise DVB frontends" => "ISL6421 SEC controller"
+
+4.) Revision 2.8:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "Conexant CX24113/CX24128 tuner for DVB-S/DSS"
+c.)"Multimedia devices" => "Customise DVB frontends" => "Conexant CX24123 based"
+d.)"Multimedia devices" => "Customise DVB frontends" => "ISL6421 SEC controller"
+
+5.) DVB-T card:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "Zarlink MT352 based"
+
+6.) DVB-C card:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "ST STV0297 based"
+
+7.) ATSC card 1st generation:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "Broadcom BCM3510"
+
+8.) ATSC card 2nd generation:
+a.)"Multimedia devices" => "Customise DVB frontends" => "Customise the frontend modules to build"
+b.)"Multimedia devices" => "Customise DVB frontends" => "NxtWave Communications NXT2002/NXT2004 based"
+c.)"Multimedia devices" => "Customise DVB frontends" => "LG Electronics LGDT3302/LGDT3303 based"
+
+Author: Uwe Bugla <uwe.bugla@gmx.de> December 2008

Documentation/email-clients.txt

@@ -213,4 +213,29 @@ TkRat (GUI)
 
 Works.  Use "Insert file..." or external editor.
 
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+Gmail (Web GUI)
+
+If you just have to use Gmail to send patches, it CAN be made to work.  It
+requires a bit of external help, though.
+
+The first problem is that Gmail converts tabs to spaces.  This will
+totally break your patches.  To prevent this, you have to use a different
+editor.  There is a firefox extension called "ViewSourceWith"
+(https://addons.mozilla.org/en-US/firefox/addon/394) which allows you to
+edit any text box in the editor of your choice.  Configure it to launch
+your favorite editor.  When you want to send a patch, use this technique.
+Once you have crafted your messsage + patch, save and exit the editor,
+which should reload the Gmail edit box.  GMAIL WILL PRESERVE THE TABS.
+Hoorah.  Apparently you can cut-n-paste literal tabs, but Gmail will
+convert those to spaces upon sending!
+
+The second problem is that Gmail converts tabs to spaces on replies.  If
+you reply to a patch, don't expect to be able to apply it as a patch.
+
+The last problem is that Gmail will base64-encode any message that has a
+non-ASCII character.  That includes things like European names.  Be aware.
+
+Gmail is not convenient for lkml patches, but CAN be made to work.
+
                                 ###

Documentation/fb/intelfb.txt

@@ -14,6 +14,7 @@ graphics devices.  These would include:
 	Intel 915GM
 	Intel 945G
 	Intel 945GM
+	Intel 945GME
 	Intel 965G
 	Intel 965GM
 

Documentation/fb/pxafb.txt

@@ -5,9 +5,13 @@ The driver supports the following options, either via
 options=<OPTIONS> when modular or video=pxafb:<OPTIONS> when built in.
 
 For example:
-	modprobe pxafb options=mode:640x480-8,passive
+	modprobe pxafb options=vmem:2M,mode:640x480-8,passive
 or on the kernel command line
-	video=pxafb:mode:640x480-8,passive
+	video=pxafb:vmem:2M,mode:640x480-8,passive
+
+vmem: VIDEO_MEM_SIZE
+	Amount of video memory to allocate (can be suffixed with K or M
+	for kilobytes or megabytes)
 
 mode:XRESxYRES[-BPP]
 	XRES == LCCR1_PPL + 1
@@ -52,3 +56,87 @@ outputen:POLARITY
 pixclockpol:POLARITY
 	pixel clock polarity
 	0 => falling edge, 1 => rising edge
+
+
+Overlay Support for PXA27x and later LCD controllers
+====================================================
+
+  PXA27x and later processors support overlay1 and overlay2 on-top of the
+  base framebuffer (although under-neath the base is also possible). They
+  support palette and no-palette RGB formats, as well as YUV formats (only
+  available on overlay2). These overlays have dedicated DMA channels and
+  behave in a similar way as a framebuffer.
+
+  However, there are some differences between these overlay framebuffers
+  and normal framebuffers, as listed below:
+
+  1. overlay can start at a 32-bit word aligned position within the base
+     framebuffer, which means they have a start (x, y). This information
+     is encoded into var->nonstd (no, var->xoffset and var->yoffset are
+     not for such purpose).
+
+  2. overlay framebuffer is allocated dynamically according to specified
+     'struct fb_var_screeninfo', the amount is decided by:
+
+        var->xres_virtual * var->yres_virtual * bpp
+
+     bpp = 16 -- for RGB565 or RGBT555
+         = 24 -- for YUV444 packed
+         = 24 -- for YUV444 planar
+	 = 16 -- for YUV422 planar (1 pixel = 1 Y + 1/2 Cb + 1/2 Cr)
+	 = 12 -- for YUV420 planar (1 pixel = 1 Y + 1/4 Cb + 1/4 Cr)
+
+     NOTE:
+
+     a. overlay does not support panning in x-direction, thus
+        var->xres_virtual will always be equal to var->xres
+
+     b. line length of overlay(s) must be on a 32-bit word boundary,
+        for YUV planar modes, it is a requirement for the component
+	with minimum bits per pixel,  e.g. for YUV420, Cr component
+	for one pixel is actually 2-bits, it means the line length
+	should be a multiple of 16-pixels
+
+     c. starting horizontal position (XPOS) should start on a 32-bit
+        word boundary, otherwise the fb_check_var() will just fail.
+
+     d. the rectangle of the overlay should be within the base plane,
+        otherwise fail
+
+     Applications should follow the sequence below to operate an overlay
+     framebuffer:
+
+         a. open("/dev/fb[1-2]", ...)
+	 b. ioctl(fd, FBIOGET_VSCREENINFO, ...)
+	 c. modify 'var' with desired parameters:
+	    1) var->xres and var->yres
+	    2) larger var->yres_virtual if more memory is required,
+	       usually for double-buffering
+	    3) var->nonstd for starting (x, y) and color format
+	    4) var->{red, green, blue, transp} if RGB mode is to be used
+	 d. ioctl(fd, FBIOPUT_VSCREENINFO, ...)
+	 e. ioctl(fd, FBIOGET_FSCREENINFO, ...)
+	 f. mmap
+	 g. ...
+
+  3. for YUV planar formats, these are actually not supported within the
+     framebuffer framework, application has to take care of the offsets
+     and lengths of each component within the framebuffer.
+
+  4. var->nonstd is used to pass starting (x, y) position and color format,
+     the detailed bit fields are shown below:
+
+    31                23  20         10          0
+     +-----------------+---+----------+----------+
+     |  ... unused ... |FOR|   XPOS   |   YPOS   |
+     +-----------------+---+----------+----------+
+
+     FOR  - color format, as defined by OVERLAY_FORMAT_* in pxafb.h
+            0 - RGB
+	    1 - YUV444 PACKED
+	    2 - YUV444 PLANAR
+	    3 - YUV422 PLANAR
+	    4 - YUR420 PLANAR
+
+     XPOS - starting horizontal position
+     YPOS - starting vertical position

Documentation/fb/uvesafb.txt

@@ -52,7 +52,7 @@ are either given on the kernel command line or as module parameters, e.g.:
 
  video=uvesafb:1024x768-32,mtrr:3,ywrap (compiled into the kernel)
 
- # modprobe uvesafb mode=1024x768-32 mtrr=3 scroll=ywrap  (module)
+ # modprobe uvesafb mode_option=1024x768-32 mtrr=3 scroll=ywrap  (module)
 
 Accepted options:
 
@@ -105,7 +105,7 @@ vtotal:n
 <mode>  The mode you want to set, in the standard modedb format.  Refer to
         modedb.txt for a detailed description.  When uvesafb is compiled as
         a module, the mode string should be provided as a value of the
-        'mode' option.
+        'mode_option' option.
 
 vbemode:x
         Force the use of VBE mode x.  The mode will only be set if it's

Documentation/fb/viafb.modes

@@ -0,0 +1,870 @@
+#
+#
+#   These data are based on the CRTC parameters in
+#
+#       VIA Integration Graphics Chip
+#       (C) 2004 VIA Technologies Inc.
+#
+
+#
+#   640x480, 60 Hz, Non-Interlaced (25.175 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      640     480
+#   Scan Frequency      31.469 kHz  59.94 Hz
+#   Sync Width      3.813 us    0.064 ms
+#               12 chars    2 lines
+#   Front Porch     0.636 us    0.318  ms
+#               2 chars     10 lines
+#   Back Porch      1.907 us    1.048  ms
+#               6 chars     33 lines
+#   Active Time     25.422 us   15.253 ms
+#               80 chars    480 lines
+#   Blank Time      6.356 us    1.430 ms
+#               20 chars    45 lines
+#   Polarity        negative    negative
+#
+
+mode "640x480-60"
+# D: 25.175 MHz, H: 31.469 kHz, V: 59.94 Hz
+    geometry 640 480 640 480 32
+    timings 39722 48 16 33 10 96 2 endmode mode "480x640-60"
+# D: 24.823 MHz, H: 39.780 kHz, V: 60.00 Hz
+    geometry 480 640 480 640 32 timings 39722 72 24 19 1 48 3 endmode
+#
+#   640x480, 75 Hz, Non-Interlaced (31.50 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      640     480
+#   Scan Frequency      37.500 kHz  75.00 Hz
+#   Sync Width      2.032 us    0.080 ms
+#               8 chars     3 lines
+#   Front Porch     0.508 us    0.027 ms
+#               2 chars     1 lines
+#   Back Porch      3.810 us    0.427 ms
+#               15 chars    16 lines
+#   Active Time     20.317 us   12.800 ms
+#               80 chars    480 lines
+#   Blank Time      6.349 us    0.533 ms
+#               25 chars    20 lines
+#   Polarity        negative    negative
+#
+    mode "640x480-75"
+# D: 31.50 MHz, H: 37.500 kHz, V: 75.00 Hz
+    geometry 640 480 640 480 32 timings 31747 120 16 16 1 64 3 endmode
+#
+#   640x480, 85 Hz, Non-Interlaced (36.000 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      640     480
+#   Scan Frequency  43.269 kHz  85.00 Hz
+#   Sync Width      1.556 us    0.069 ms
+#               7 chars     3 lines
+#   Front Porch     1.556 us    0.023 ms
+#               7 chars     1 lines
+#   Back Porch      2.222 us    0.578 ms
+#               10 chars    25 lines
+#   Active Time     17.778 us   11.093 ms
+#               80 chars    480 lines
+#   Blank Time      5.333 us    0.670 ms
+#               24 chars    29 lines
+#   Polarity        negative    negative
+#
+    mode "640x480-85"
+# D: 36.000 MHz, H: 43.269 kHz, V: 85.00 Hz
+    geometry 640 480 640 480 32 timings 27777 80 56 25 1 56 3 endmode
+#
+#   640x480, 100 Hz, Non-Interlaced (43.163 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      640     480
+#   Scan Frequency      50.900 kHz  100.00 Hz
+#   Sync Width      1.483 us    0.058 ms
+#               8 chars     3 lines
+#   Front Porch     0.927 us    0.019 ms
+#               5 chars     1 lines
+#   Back Porch      2.409 us    0.475 ms
+#               13 chars    25 lines
+#   Active Time     14.827 us   9.430 ms
+#               80 chars    480 lines
+#   Blank Time      4.819 us    0.570 ms
+#               26 chars    29 lines
+#   Polarity        positive    positive
+#
+    mode "640x480-100"
+# D: 43.163 MHz, H: 50.900 kHz, V: 100.00 Hz
+    geometry 640 480 640 480 32 timings 23168 104 40 25 1 64 3 endmode
+#
+#   640x480, 120 Hz, Non-Interlaced (52.406 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      640     480
+#   Scan Frequency      61.800 kHz  120.00 Hz
+#   Sync Width      1.221 us    0.048 ms
+#               8 chars         3 lines
+#   Front Porch     0.763 us    0.016 ms
+#               5 chars     1 lines
+#   Back Porch      1.984 us    0.496 ms
+#               13 chars    31 lines
+#   Active Time     12.212 us   7.767 ms
+#               80 chars    480 lines
+#   Blank Time      3.969 us    0.566 ms
+#               26 chars    35 lines
+#   Polarity        positive    positive
+#
+    mode "640x480-120"
+# D: 52.406 MHz, H: 61.800 kHz, V: 120.00 Hz
+    geometry 640 480 640 480 32 timings 19081 104 40 31 1 64 3 endmode
+#
+#   720x480, 60 Hz, Non-Interlaced (26.880 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      720     480
+#   Scan Frequency      30.000 kHz  60.241 Hz
+#   Sync Width      2.679 us    0.099 ms
+#               9 chars     3 lines
+#   Front Porch     0.595 us    0.033 ms
+#               2 chars     1 lines
+#   Back Porch      3.274 us    0.462 ms
+#               11 chars    14 lines
+#   Active Time     26.786 us   16.000 ms
+#               90 chars    480 lines
+#   Blank Time      6.548 us    0.600 ms
+#               22 chars    18 lines
+#   Polarity        positive    positive
+#
+    mode "720x480-60"
+# D: 26.880 MHz, H: 30.000 kHz, V: 60.24 Hz
+    geometry 720 480 720 480 32 timings 37202 88 16 14 1 72 3 endmode
+#
+#   800x480, 60 Hz, Non-Interlaced (29.581 MHz dotclock)
+#
+#               Horizontal    Vertical
+#   Resolution      800         480
+#   Scan Frequency  29.892 kHz  60.00 Hz
+#   Sync Width      2.704 us    100.604 us
+#                   10 chars    3 lines
+#   Front Porch     0.541 us    33.535 us
+#                   2 chars     1 lines
+#   Back Porch      3.245 us    435.949 us
+#                   12 chars    13 lines
+#   Active Time     27.044 us   16.097 ms
+#                   100 chars   480 lines
+#   Blank Time      6.491 us    0.570 ms
+#                   24 chars    17 lines
+#   Polarity        positive    positive
+#
+    mode "800x480-60"
+# D: 29.500 MHz, H: 29.738 kHz, V: 60.00 Hz
+    geometry 800 480 800 480 32 timings 33805 96 24 10 3 72 7 endmode
+#
+#   720x576, 60 Hz, Non-Interlaced (32.668 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      720     576
+#   Scan Frequency      35.820 kHz  60.00 Hz
+#   Sync Width      2.204 us    0.083 ms
+#               9 chars     3 lines
+#   Front Porch     0.735 us    0.027 ms
+#               3 chars     1 lines
+#   Back Porch      2.939 us    0.459 ms
+#               12 chars    17 lines
+#   Active Time     22.040 us   16.080 ms
+#               90 chars    476 lines
+#   Blank Time      5.877 us    0.586 ms
+#               24 chars    21 lines
+#   Polarity        positive    positive
+#
+    mode "720x576-60"
+# D: 32.668 MHz, H: 35.820 kHz, V: 60.00 Hz
+    geometry 720 576 720 576 32 timings 30611 96 24 17 1 72 3 endmode
+#
+#   800x600, 60 Hz, Non-Interlaced (40.00 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      800     600
+#   Scan Frequency      37.879 kHz  60.32 Hz
+#   Sync Width      3.200 us    0.106 ms
+#               16 chars    4 lines
+#   Front Porch     1.000 us    0.026 ms
+#               5 chars     1 lines
+#   Back Porch      2.200 us    0.607 ms
+#               11 chars    23 lines
+#   Active Time     20.000 us   15.840 ms
+#               100 chars   600 lines
+#   Blank Time      6.400 us    0.739 ms
+#               32 chars    28 lines
+#   Polarity        positive    positive
+#
+    mode "800x600-60"
+# D: 40.00 MHz, H: 37.879 kHz, V: 60.32 Hz
+    geometry 800 600 800 600 32
+    timings 25000 88 40 23 1 128 4 hsync high vsync high endmode
+#
+#   800x600, 75 Hz, Non-Interlaced (49.50 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      800     600
+#   Scan Frequency      46.875 kHz  75.00 Hz
+#   Sync Width      1.616 us    0.064 ms
+#               10 chars    3 lines
+#   Front Porch     0.323 us    0.021 ms
+#               2 chars     1 lines
+#   Back Porch      3.232 us    0.448 ms
+#               20 chars    21 lines
+#   Active Time     16.162 us   12.800 ms
+#               100 chars   600 lines
+#   Blank Time      5.172 us    0.533 ms
+#               32 chars    25 lines
+#   Polarity        positive    positive
+#
+    mode "800x600-75"
+# D: 49.50 MHz, H: 46.875 kHz, V: 75.00 Hz
+    geometry 800 600 800 600 32
+    timings 20203 160 16 21 1 80 3 hsync high vsync high endmode
+#
+#   800x600, 85 Hz, Non-Interlaced (56.25 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      800     600
+#   Scan Frequency      53.674 kHz  85.061 Hz
+#   Sync Width      1.138 us    0.056 ms
+#               8 chars     3 lines
+#   Front Porch     0.569 us    0.019 ms
+#               4 chars     1 lines
+#   Back Porch      2.702 us    0.503 ms
+#               19 chars    27 lines
+#   Active Time     14.222 us   11.179 ms
+#               100 chars   600 lines
+#   Blank Time      4.409 us    0.578 ms
+#               31 chars    31 lines
+#   Polarity        positive    positive
+#
+    mode "800x600-85"
+# D: 56.25 MHz, H: 53.674 kHz, V: 85.061 Hz
+    geometry 800 600 800 600 32
+    timings 17777 152 32 27 1 64 3 hsync high vsync high endmode
+#
+#   800x600, 100 Hz, Non-Interlaced (67.50 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      800     600
+#   Scan Frequency      62.500 kHz  100.00 Hz
+#   Sync Width      0.948 us    0.064 ms
+#               8 chars     4 lines
+#   Front Porch     0.000 us    0.112 ms
+#               0 chars     7 lines
+#   Back Porch      3.200 us    0.224 ms
+#               27 chars    14 lines
+#   Active Time     11.852 us   9.600 ms
+#               100 chars   600 lines
+#   Blank Time      4.148 us    0.400 ms
+#               35 chars    25 lines
+#   Polarity        positive    positive
+#
+    mode "800x600-100"
+# D: 67.50 MHz, H: 62.500 kHz, V: 100.00 Hz
+    geometry 800 600 800 600 32
+    timings 14667 216 0 14 7 64 4 hsync high vsync high endmode
+#
+#   800x600, 120 Hz, Non-Interlaced (83.950 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      800     600
+#   Scan Frequency  77.160 kHz  120.00 Hz
+#   Sync Width      1.048 us    0.039 ms
+#               11 chars    3 lines
+#   Front Porch     0.667 us    0.013 ms
+#               7 chars     1 lines
+#   Back Porch      1.715 us    0.507 ms
+#               18 chars    39 lines
+#   Active Time     9.529 us    7.776 ms
+#               100 chars   600 lines
+#   Blank Time      3.431 us    0.557 ms
+#               36 chars    43 lines
+#   Polarity        positive    positive
+#
+    mode "800x600-120"
+# D: 83.950 MHz, H: 77.160 kHz, V: 120.00 Hz
+    geometry 800 600 800 600 32
+    timings 11912 144 56 39 1 88 3 hsync high vsync high endmode
+#
+#   848x480, 60 Hz, Non-Interlaced (31.490 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      848     480
+#   Scan Frequency  29.820 kHz  60.00 Hz
+#   Sync Width      2.795 us    0.099 ms
+#               11 chars    3 lines
+#   Front Porch     0.508 us    0.033 ms
+#               2 chars     1 lines
+#   Back Porch      3.303 us    0.429 ms
+#               13 chars    13 lines
+#   Active Time     26.929 us   16.097 ms
+#               106 chars   480 lines
+#   Blank Time      6.605 us    0.570 ms
+#               26 chars    17 lines
+#   Polarity        positive    positive
+#
+    mode "848x480-60"
+# D: 31.500 MHz, H: 29.830 kHz, V: 60.00 Hz
+    geometry 848 480 848 480 32
+    timings 31746 104 24 12 3 80 5 hsync high vsync high endmode
+#
+#   856x480, 60 Hz, Non-Interlaced (31.728 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      856     480
+#   Scan Frequency  29.820 kHz  60.00 Hz
+#   Sync Width      2.774 us    0.099 ms
+#               11 chars    3 lines
+#   Front Porch     0.504 us    0.033 ms
+#               2 chars     1 lines
+#   Back Porch      3.728 us    0.429 ms
+#               13 chars    13 lines
+#   Active Time     26.979 us   16.097 ms
+#               107 chars   480 lines
+#   Blank Time      6.556 us    0.570 ms
+#               26 chars    17 lines
+#   Polarity        positive    positive
+#
+    mode "856x480-60"
+# D: 31.728 MHz, H: 29.820 kHz, V: 60.00 Hz
+    geometry 856 480 856 480 32
+    timings 31518 104 16 13 1 88 3
+    hsync high vsync high endmode mode "960x600-60"
+# D: 45.250 MHz, H: 37.212 kHz, V: 60.00 Hz
+    geometry 960 600 960 600 32 timings 22099 128 32 15 3 96 6 endmode
+#
+#   1000x600, 60 Hz, Non-Interlaced (48.068 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1000     600
+#   Scan Frequency  37.320 kHz  60.00 Hz
+#   Sync Width      2.164 us    0.080 ms
+#               13 chars    3 lines
+#   Front Porch     0.832 us    0.027 ms
+#               5 chars     1 lines
+#   Back Porch      2.996 us    0.483 ms
+#               18 chars    18 lines
+#   Active Time     20.804 us   16.077 ms
+#               125 chars   600 lines
+#   Blank Time      5.991 us    0.589 ms
+#               36 chars    22 lines
+#   Polarity        negative    positive
+#
+    mode "1000x600-60"
+# D: 48.068 MHz, H: 37.320 kHz, V: 60.00 Hz
+    geometry 1000 600 1000 600 32
+    timings 20834 144 40 18 1 104 3 endmode mode "1024x576-60"
+# D: 46.996 MHz, H: 35.820 kHz, V: 60.00 Hz
+    geometry 1024 576 1024 576 32
+    timings 21278 144 40 17 1 104 3 endmode mode "1024x600-60"
+# D: 48.964 MHz, H: 37.320 kHz, V: 60.00 Hz
+    geometry 1024 600 1024 600 32
+    timings 20461 144 40 18 1 104 3 endmode mode "1088x612-60"
+# D: 52.952 MHz, H: 38.040 kHz, V: 60.00 Hz
+    geometry 1088 612 1088 612 32 timings 18877 152 48 16 3 104 5 endmode
+#
+#   1024x512, 60 Hz, Non-Interlaced (41.291 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1024    512
+#   Scan Frequency  31.860 kHz  60.00 Hz
+#   Sync Width      2.519 us    0.094 ms
+#               13 chars    3 lines
+#   Front Porch     0.775 us    0.031 ms
+#               4 chars     1 lines
+#   Back Porch      3.294 us    0.465 ms
+#               17 chars    15 lines
+#   Active Time     24.800 us   16.070 ms
+#               128 chars   512 lines
+#   Blank Time      6.587 us    0.596 ms
+#               34 chars    19 lines
+#   Polarity        positive    positive
+#
+    mode "1024x512-60"
+# D: 41.291 MHz, H: 31.860 kHz, V: 60.00 Hz
+    geometry 1024 512 1024 512 32
+    timings 24218 126 32 15 1 104 3 hsync high vsync high endmode
+#
+#   1024x600, 60 Hz, Non-Interlaced (48.875 MHz dotclock)
+#
+#                     Horizontal  Vertical
+#   Resolution          1024        768
+#   Scan Frequency      37.252 kHz  60.00 Hz
+#   Sync Width          2.128 us    80.532us
+#                       13 chars    3 lines
+#   Front Porch        0.818 us     26.844 us
+#                       5 chars     1 lines
+#   Back Porch          2.946 us    483.192 us
+#                       18 chars    18 lines
+#   Active Time         20.951 us   16.697 ms
+#                       128 chars   622 lines
+#   Blank Time          5.893 us    0.591 ms
+#                       36 chars    22 lines
+#   Polarity            negative    positive
+#
+#mode "1024x600-60"
+#     # D: 48.875 MHz, H: 37.252 kHz, V: 60.00 Hz
+#     geometry 1024 600 1024 600 32
+#    timings 20460  144 40 18 1 104  3
+# endmode
+#
+#   1024x768, 60 Hz, Non-Interlaced (65.00 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1024        768
+#   Scan Frequency      48.363 kHz  60.00 Hz
+#   Sync Width      2.092 us    0.124 ms
+#               17 chars    6 lines
+#   Front Porch     0.369 us    0.062 ms
+#               3 chars     3 lines
+#   Back Porch      2.462 us    0.601 ms
+#               20 chars    29 lines
+#   Active Time     15.754 us   15.880 ms
+#               128 chars   768 lines
+#   Blank Time      4.923 us    0.786 ms
+#               40 chars    38 lines
+#   Polarity        negative    negative
+#
+    mode "1024x768-60"
+# D: 65.00 MHz, H: 48.363 kHz, V: 60.00 Hz
+    geometry 1024 768 1024 768 32 timings 15385 160 24 29 3 136 6 endmode
+#
+#   1024x768, 75 Hz, Non-Interlaced (78.75 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1024        768
+#   Scan Frequency      60.023 kHz  75.03 Hz
+#   Sync Width      1.219 us    0.050 ms
+#               12 chars    3 lines
+#   Front Porch     0.203 us    0.017 ms
+#               2 chars     1 lines
+#   Back Porch      2.235 us    0.466 ms
+#               22 chars    28 lines
+#   Active Time     13.003 us   12.795 ms
+#               128 chars   768 lines
+#   Blank Time      3.657 us    0.533 ms
+#               36 chars    32 lines
+#   Polarity        positive    positive
+#
+    mode "1024x768-75"
+# D: 78.75 MHz, H: 60.023 kHz, V: 75.03 Hz
+    geometry 1024 768 1024 768 32
+    timings 12699 176 16 28 1 96 3 hsync high vsync high endmode
+#
+#   1024x768, 85 Hz, Non-Interlaced (94.50 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1024        768
+#   Scan Frequency  68.677 kHz  85.00 Hz
+#   Sync Width      1.016 us    0.044 ms
+#               12 chars    3 lines
+#   Front Porch     0.508 us    0.015 ms
+#               6 chars     1 lines
+#   Back Porch      2.201 us    0.524 ms
+#               26 chars    36 lines
+#   Active Time     10.836 us   11.183 ms
+#               128 chars   768 lines
+#   Blank Time      3.725 us    0.582 ms
+#               44 chars    40 lines
+#   Polarity        positive    positive
+#
+    mode "1024x768-85"
+# D: 94.50 MHz, H: 68.677 kHz, V: 85.00 Hz
+    geometry 1024 768 1024 768 32
+    timings 10582 208 48 36 1 96 3 hsync high vsync high endmode
+#
+#   1024x768, 100 Hz, Non-Interlaced (110.0 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1024        768
+#   Scan Frequency      79.023 kHz  99.78 Hz
+#   Sync Width      0.800 us    0.101 ms
+#               11 chars    8 lines
+#   Front Porch     0.000 us    0.000 ms
+#               0 chars     0 lines
+#   Back Porch      2.545 us    0.202 ms
+#               35 chars    16 lines
+#   Active Time     9.309 us    9.719 ms
+#               128 chars   768 lines
+#   Blank Time      3.345 us    0.304 ms
+#               46 chars    24 lines
+#   Polarity        negative    negative
+#
+    mode "1024x768-100"
+# D: 113.3 MHz, H: 79.023 kHz, V: 99.78 Hz
+    geometry 1024 768 1024 768 32
+    timings 8825 280 0 16 0 88 8 endmode mode "1152x720-60"
+# D: 66.750 MHz, H: 44.859 kHz, V: 60.00 Hz
+    geometry 1152 720 1152 720 32 timings 14981 168 56 19 3 112 6 endmode
+#
+#   1152x864, 75 Hz, Non-Interlaced (110.0 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1152        864
+#   Scan Frequency      75.137 kHz  74.99 Hz
+#   Sync Width      1.309 us    0.106 ms
+#               18 chars    8 lines
+#   Front Porch     0.245 us    0.599 ms
+#               3 chars     45 lines
+#   Back Porch      1.282 us    1.132 ms
+#               18 chars    85 lines
+#   Active Time     10.473 us   11.499 ms
+#               144 chars   864 lines
+#   Blank Time      2.836 us    1.837 ms
+#               39 chars    138 lines
+#   Polarity        positive    positive
+#
+    mode "1152x864-75"
+# D: 110.0 MHz, H: 75.137 kHz, V: 74.99 Hz
+    geometry 1152 864 1152 864 32
+    timings 9259 144 24 85 45 144 8
+    hsync high vsync high endmode mode "1200x720-60"
+# D: 70.184 MHz, H: 44.760 kHz, V: 60.00 Hz
+    geometry 1200 720 1200 720 32
+    timings 14253 184 28 22 1 128 3 endmode mode "1280x600-60"
+# D: 61.503 MHz, H: 37.320 kHz, V: 60.00 Hz
+    geometry 1280 600 1280 600 32
+    timings 16260 184 28 18 1 128 3 endmode mode "1280x720-50"
+# D: 60.466 MHz, H: 37.050 kHz, V: 50.00 Hz
+    geometry 1280 720 1280 720 32
+    timings 16538 176 48 17 1 128 3 endmode mode "1280x768-50"
+# D: 65.178 MHz, H: 39.550 kHz, V: 50.00 Hz
+    geometry 1280 768 1280 768 32 timings 15342 184 28 19 1 128 3 endmode
+#
+#   1280x768, 60 Hz, Non-Interlaced (80.136 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280    768
+#   Scan Frequency  47.700 kHz  60.00 Hz
+#   Sync Width      1.697 us    0.063 ms
+#               17 chars    3 lines
+#   Front Porch     0.799 us    0.021 ms
+#               8 chars     1 lines
+#   Back Porch      2.496 us    0.483 ms
+#               25 chars    23 lines
+#   Active Time     15.973 us   16.101 ms
+#               160 chars   768 lines
+#   Blank Time      4.992 us    0.566 ms
+#               50 chars    27 lines
+#   Polarity        positive    positive
+#
+    mode "1280x768-60"
+# D: 80.13 MHz, H: 47.700 kHz, V: 60.00 Hz
+    geometry 1280 768 1280 768 32
+    timings 12480 200 48 23 1 126 3 hsync high vsync high endmode
+#
+#   1280x800, 60 Hz, Non-Interlaced (83.375 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280    800
+#   Scan Frequency  49.628 kHz  60.00 Hz
+#   Sync Width      1.631 us    60.450 us
+#                   17 chars    3 lines
+#   Front Porch     0.768 us    20.15 us
+#                   8 chars     1 lines
+#   Back Porch      2.399 us    0.483 ms
+#                   25 chars    24 lines
+#   Active Time     15.352 us   16.120 ms
+#                   160 chars   800 lines
+#   Blank Time      4.798 us    0.564 ms
+#                   50 chars    28 lines
+#   Polarity        negtive    positive
+#
+    mode "1280x800-60"
+# D: 83.500 MHz, H: 49.702 kHz, V: 60.00 Hz
+    geometry 1280 800 1280 800 32 timings 11994 200 72 22 3 128 6 endmode
+#
+#   1280x960, 60 Hz, Non-Interlaced (108.00 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280    960
+#   Scan Frequency  60.000 kHz  60.00 Hz
+#   Sync Width      1.037 us    0.050 ms
+#               14 chars    3 lines
+#   Front Porch     0.889 us    0.017 ms
+#               12 chars    1 lines
+#   Back Porch      2.889 us    0.600 ms
+#               39 chars    36 lines
+#   Active Time     11.852 us   16.000 ms
+#               160 chars   960 lines
+#   Blank Time      4.815 us    0.667 ms
+#               65 chars    40 lines
+#   Polarity        positive    positive
+#
+    mode "1280x960-60"
+# D: 108.00 MHz, H: 60.000 kHz, V: 60.00 Hz
+    geometry 1280 960 1280 960 32
+    timings 9259 312 96 36 1 112 3 hsync high vsync high endmode
+#
+#   1280x1024, 60 Hz, Non-Interlaced (108.00 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280        1024
+#   Scan Frequency      63.981 kHz  60.02 Hz
+#   Sync Width      1.037 us    0.047 ms
+#               14 chars    3 lines
+#   Front Porch     0.444 us    0.015 ms
+#               6 chars     1 lines
+#   Back Porch      2.297 us    0.594 ms
+#               31 chars    38 lines
+#   Active Time     11.852 us   16.005 ms
+#               160 chars   1024 lines
+#   Blank Time      3.778 us    0.656 ms
+#               51 chars    42 lines
+#   Polarity        positive    positive
+#
+    mode "1280x1024-60"
+# D: 108.00 MHz, H: 63.981 kHz, V: 60.02 Hz
+    geometry 1280 1024 1280 1024 32
+    timings 9260 248 48 38 1 112 3 hsync high vsync high endmode
+#
+#   1280x1024, 75 Hz, Non-Interlaced (135.00 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280        1024
+#   Scan Frequency      79.976 kHz  75.02 Hz
+#   Sync Width      1.067 us    0.038 ms
+#               18 chars    3 lines
+#   Front Porch     0.119 us    0.012 ms
+#               2 chars     1 lines
+#   Back Porch      1.837 us    0.475 ms
+#               31 chars    38 lines
+#   Active Time     9.481 us    12.804 ms
+#               160 chars   1024 lines
+#   Blank Time      3.022 us    0.525 ms
+#               51 chars    42 lines
+#   Polarity        positive    positive
+#
+    mode "1280x1024-75"
+# D: 135.00 MHz, H: 79.976 kHz, V: 75.02 Hz
+    geometry 1280 1024 1280 1024 32
+    timings 7408 248 16 38 1 144 3 hsync high vsync high endmode
+#
+#   1280x1024, 85 Hz, Non-Interlaced (157.50 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280        1024
+#   Scan Frequency  91.146 kHz  85.02 Hz
+#   Sync Width      1.016 us    0.033 ms
+#               20 chars    3 lines
+#   Front Porch     0.406 us    0.011 ms
+#               8 chars     1 lines
+#   Back Porch      1.422 us    0.483 ms
+#               28 chars    44 lines
+#   Active Time     8.127 us    11.235 ms
+#               160 chars   1024 lines
+#   Blank Time      2.844 us    0.527 ms
+#               56 chars    48 lines
+#   Polarity        positive    positive
+#
+    mode "1280x1024-85"
+# D: 157.50 MHz, H: 91.146 kHz, V: 85.02 Hz
+    geometry 1280 1024 1280 1024 32
+    timings 6349 224 64 44 1 160 3
+    hsync high vsync high endmode mode "1440x900-60"
+# D: 106.500 MHz, H: 55.935 kHz, V: 60.00 Hz
+    geometry 1440 900 1440 900 32
+    timings 9390 232 80 25 3 152 6
+    hsync high vsync high endmode mode "1440x900-75"
+# D: 136.750 MHz, H: 70.635 kHz, V: 75.00 Hz
+    geometry 1440 900 1440 900 32
+    timings 7315 248 96 33 3 152 6 hsync high vsync high endmode
+#
+#   1440x1050, 60 Hz, Non-Interlaced (125.10 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1440        1050
+#   Scan Frequency      65.220 kHz  60.00 Hz
+#   Sync Width      1.204 us    0.046 ms
+#               19 chars    3 lines
+#   Front Porch     0.760 us    0.015 ms
+#               12 chars    1 lines
+#   Back Porch      1.964 us    0.495 ms
+#               31 chars    33 lines
+#   Active Time     11.405 us   16.099 ms
+#               180 chars   1050 lines
+#   Blank Time      3.928 us    0.567 ms
+#               62 chars    37 lines
+#   Polarity        positive    positive
+#
+    mode "1440x1050-60"
+# D: 125.10 MHz, H: 65.220 kHz, V: 60.00 Hz
+    geometry 1440 1050 1440 1050 32
+    timings 7993 248 96 33 1 152 3
+    hsync high vsync high endmode mode "1600x900-60"
+# D: 118.250 MHz, H: 55.990 kHz, V: 60.00 Hz
+    geometry 1600 900 1600 900 32
+    timings 8415 256 88 26 3 168 5 endmode mode "1600x1024-60"
+# D: 136.358 MHz, H: 63.600 kHz, V: 60.00 Hz
+    geometry 1600 1024 1600 1024 32 timings 7315 272 104 32 1 168 3 endmode
+#
+#   1600x1200, 60 Hz, Non-Interlaced (156.00 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1600        1200
+#   Scan Frequency      76.200 kHz  60.00 Hz
+#   Sync Width      1.026 us    0.105 ms
+#               20 chars    8 lines
+#   Front Porch     0.205 us    0.131 ms
+#               4 chars     10 lines
+#   Back Porch      1.636 us    0.682 ms
+#               32 chars    52 lines
+#   Active Time     10.256 us   15.748 ms
+#               200 chars   1200 lines
+#   Blank Time      2.872 us    0.866 ms
+#               56 chars    66 lines
+#   Polarity        negative    negative
+#
+    mode "1600x1200-60"
+# D: 156.00 MHz, H: 76.200 kHz, V: 60.00 Hz
+    geometry 1600 1200 1600 1200 32 timings 6172 256 32 52 10 160 8 endmode
+#
+#   1600x1200, 75 Hz, Non-Interlaced (202.50 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1600        1200
+#   Scan Frequency  93.750 kHz  75.00 Hz
+#   Sync Width      0.948 us    0.032 ms
+#               24 chars    3 lines
+#   Front Porch     0.316 us    0.011 ms
+#               8 chars     1 lines
+#   Back Porch      1.501 us    0.491 ms
+#               38 chars    46 lines
+#   Active Time     7.901 us    12.800 ms
+#               200 chars   1200 lines
+#   Blank Time      2.765 us    0.533 ms
+#               70 chars    50 lines
+#   Polarity    positive    positive
+#
+    mode "1600x1200-75"
+# D: 202.50 MHz, H: 93.750 kHz, V: 75.00 Hz
+    geometry 1600 1200 1600 1200 32
+    timings 4938 304 64 46 1 192 3
+    hsync high vsync high endmode mode "1680x1050-60"
+# D: 146.250 MHz, H: 65.290 kHz, V: 59.954 Hz
+    geometry 1680 1050 1680 1050 32
+    timings 6814 280 104 30 3 176 6
+    hsync high vsync high endmode mode "1680x1050-75"
+# D: 187.000 MHz, H: 82.306 kHz, V: 74.892 Hz
+    geometry 1680 1050 1680 1050 32
+    timings 5348 296 120 40 3 176 6
+    hsync high vsync high endmode mode "1792x1344-60"
+# D: 202.975 MHz, H: 83.460 kHz, V: 60.00 Hz
+    geometry 1792 1344 1792 1344 32
+    timings 4902 320 128 43 1 192 3
+    hsync high vsync high endmode mode "1856x1392-60"
+# D: 218.571 MHz, H: 86.460 kHz, V: 60.00 Hz
+    geometry 1856 1392 1856 1392 32
+    timings 4577 336 136 45 1 200 3
+    hsync high vsync high endmode mode "1920x1200-60"
+# D: 193.250 MHz, H: 74.556 kHz, V: 60.00 Hz
+    geometry 1920 1200 1920 1200 32
+    timings 5173 336 136 36 3 200 6
+    hsync high vsync high endmode mode "1920x1440-60"
+# D: 234.000 MHz, H:90.000 kHz, V: 60.00 Hz
+    geometry 1920 1440 1920 1440 32
+    timings 4274 344 128 56 1 208 3
+    hsync high vsync high endmode mode "1920x1440-75"
+# D: 297.000 MHz, H:112.500 kHz, V: 75.00 Hz
+    geometry 1920 1440 1920 1440 32
+    timings 3367 352 144 56 1 224 3
+    hsync high vsync high endmode mode "2048x1536-60"
+# D: 267.250 MHz, H: 95.446 kHz, V: 60.00 Hz
+    geometry 2048 1536 2048 1536 32
+    timings 3742 376 152 49 3 224 4 hsync high vsync high endmode
+#
+#   1280x720, 60 Hz, Non-Interlaced (74.481 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1280        720
+#   Scan Frequency      44.760 kHz  60.00 Hz
+#   Sync Width      1.826 us    67.024 ms
+#               17 chars    3 lines
+#   Front Porch     0.752 us    22.341 ms
+#               7 chars     1 lines
+#   Back Porch      2.578 us    491.510 ms
+#               24 chars    22 lines
+#   Active Time     17.186 us   16.086 ms
+#               160 chars   720 lines
+#   Blank Time      5.156 us    0.581 ms
+#               48 chars    26 lines
+#   Polarity        negative    negative
+#
+    mode "1280x720-60"
+# D: 74.481 MHz, H: 44.760 kHz, V: 60.00 Hz
+    geometry 1280 720 1280 720 32 timings 13426 192 64 22 1 136 3 endmode
+#
+#   1920x1080, 60 Hz, Non-Interlaced (172.798 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1920        1080
+#   Scan Frequency      67.080 kHz  60.00 Hz
+#   Sync Width      1.204 us    44.723 ms
+#               26 chars    3 lines
+#   Front Porch     0.694 us    14.908 ms
+#               15 chars     1 lines
+#   Back Porch      1.898 us    506.857 ms
+#               41 chars    34 lines
+#   Active Time     11.111 us   16.100 ms
+#               240 chars   1080 lines
+#   Blank Time      3.796 us    0.566 ms
+#               82 chars    38 lines
+#   Polarity        negative    negative
+#
+    mode "1920x1080-60"
+# D: 74.481 MHz, H: 67.080 kHz, V: 60.00 Hz
+    geometry 1920 1080 1920 1080 32 timings 5787 328 120 34 1 208 3 endmode
+#
+#   1400x1050, 60 Hz, Non-Interlaced (122.61 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1400        1050
+#   Scan Frequency      65.218 kHz  59.99 Hz
+#   Sync Width      1.037 us    0.047 ms
+#               19 chars    3 lines
+#   Front Porch     0.444 us    0.015 ms
+#               11 chars     1 lines
+#   Back Porch      1.185 us    0.188 ms
+#               30 chars    33 lines
+#   Active Time     12.963 us   16.411 ms
+#               175 chars   1050 lines
+#   Blank Time      2.667 us    0.250 ms
+#               60 chars    37 lines
+#   Polarity        negative    positive
+#
+    mode "1400x1050-60"
+# D: 122.750 MHz, H: 65.317 kHz, V: 59.99 Hz
+    geometry 1400 1050 1408 1050 32
+    timings 8214 232 88 32 3 144 4 endmode mode "1400x1050-75"
+# D: 156.000 MHz, H: 82.278 kHz, V: 74.867 Hz
+    geometry 1400 1050 1408 1050 32 timings 6410 248 104 42 3 144 4 endmode
+#
+#   1366x768, 60 Hz, Non-Interlaced (85.86 MHz dotclock)
+#
+#               Horizontal  Vertical
+#   Resolution      1366        768
+#   Scan Frequency      47.700 kHz  60.00 Hz
+#   Sync Width      1.677 us    0.063 ms
+#               18 chars    3 lines
+#   Front Porch     0.839 us    0.021 ms
+#               9 chars     1 lines
+#   Back Porch      2.516 us    0.482 ms
+#               27 chars    23 lines
+#   Active Time     15.933 us   16.101 ms
+#               171 chars   768 lines
+#   Blank Time      5.031 us    0.566 ms
+#               54 chars    27 lines
+#   Polarity        negative    positive
+#
+    mode "1360x768-60"
+# D: 84.750 MHz, H: 47.720 kHz, V: 60.00 Hz
+    geometry 1360 768 1360 768 32
+    timings 11799 208 72 22 3 136 5 endmode mode "1366x768-60"
+# D: 85.86 MHz, H: 47.700 kHz, V: 60.00 Hz
+    geometry 1366 768 1366 768 32
+    timings 11647 216 72 23 1 144 3 endmode mode "1366x768-50"
+# D: 69,924 MHz, H: 39.550 kHz, V: 50.00 Hz
+    geometry 1366 768 1366 768 32 timings 14301 200 56 19 1 144 3 endmode

Documentation/fb/viafb.txt

@@ -0,0 +1,214 @@
+
+        VIA Integration Graphic Chip Console Framebuffer Driver
+
+[Platform]
+-----------------------
+    The console framebuffer driver is for graphics chips of
+    VIA UniChrome Family(CLE266, PM800 / CN400 / CN300,
+                        P4M800CE / P4M800Pro / CN700 / VN800,
+                        CX700 / VX700, K8M890, P4M890,
+                        CN896 / P4M900, VX800)
+
+[Driver features]
+------------------------
+    Device: CRT, LCD, DVI
+
+    Support viafb_mode:
+        CRT:
+            640x480(60, 75, 85, 100, 120 Hz), 720x480(60 Hz),
+            720x576(60 Hz), 800x600(60, 75, 85, 100, 120 Hz),
+            848x480(60 Hz), 856x480(60 Hz), 1024x512(60 Hz),
+            1024x768(60, 75, 85, 100 Hz), 1152x864(75 Hz),
+            1280x768(60 Hz), 1280x960(60 Hz), 1280x1024(60, 75, 85 Hz),
+            1440x1050(60 Hz), 1600x1200(60, 75 Hz), 1280x720(60 Hz),
+            1920x1080(60 Hz), 1400x1050(60 Hz), 800x480(60 Hz)
+
+    color depth: 8 bpp, 16 bpp, 32 bpp supports.
+
+    Support 2D hardware accelerator.
+
+[Using the viafb module]
+-- -- --------------------
+    Start viafb with default settings:
+        #modprobe viafb
+
+    Start viafb with with user options:
+        #modprobe viafb viafb_mode=800x600 viafb_bpp=16 viafb_refresh=60
+                  viafb_active_dev=CRT+DVI viafb_dvi_port=DVP1
+                  viafb_mode1=1024x768 viafb_bpp=16 viafb_refresh1=60
+                  viafb_SAMM_ON=1
+
+    viafb_mode:
+        640x480 (default)
+        720x480
+        800x600
+        1024x768
+        ......
+
+    viafb_bpp:
+        8, 16, 32 (default:32)
+
+    viafb_refresh:
+        60, 75, 85, 100, 120 (default:60)
+
+    viafb_lcd_dsp_method:
+        0 : expansion (default)
+        1 : centering
+
+    viafb_lcd_mode:
+        0 : LCD panel with LSB data format input (default)
+        1 : LCD panel with MSB data format input
+
+    viafb_lcd_panel_id:
+        0 : Resolution: 640x480, Channel: single, Dithering: Enable
+        1 : Resolution: 800x600, Channel: single, Dithering: Enable
+        2 : Resolution: 1024x768, Channel: single, Dithering: Enable (default)
+        3 : Resolution: 1280x768, Channel: single, Dithering: Enable
+        4 : Resolution: 1280x1024, Channel: dual, Dithering: Enable
+        5 : Resolution: 1400x1050, Channel: dual, Dithering: Enable
+        6 : Resolution: 1600x1200, Channel: dual, Dithering: Enable
+
+        8 : Resolution: 800x480, Channel: single, Dithering: Enable
+        9 : Resolution: 1024x768, Channel: dual, Dithering: Enable
+        10: Resolution: 1024x768, Channel: single, Dithering: Disable
+        11: Resolution: 1024x768, Channel: dual, Dithering: Disable
+        12: Resolution: 1280x768, Channel: single, Dithering: Disable
+        13: Resolution: 1280x1024, Channel: dual, Dithering: Disable
+        14: Resolution: 1400x1050, Channel: dual, Dithering: Disable
+        15: Resolution: 1600x1200, Channel: dual, Dithering: Disable
+        16: Resolution: 1366x768, Channel: single, Dithering: Disable
+        17: Resolution: 1024x600, Channel: single, Dithering: Enable
+        18: Resolution: 1280x768, Channel: dual, Dithering: Enable
+        19: Resolution: 1280x800, Channel: single, Dithering: Enable
+
+    viafb_accel:
+        0 : No 2D Hardware Acceleration
+        1 : 2D Hardware Acceleration (default)
+
+    viafb_SAMM_ON:
+        0 : viafb_SAMM_ON disable (default)
+        1 : viafb_SAMM_ON enable
+
+    viafb_mode1: (secondary display device)
+        640x480 (default)
+        720x480
+        800x600
+        1024x768
+        ... ...
+
+    viafb_bpp1: (secondary display device)
+        8, 16, 32 (default:32)
+
+    viafb_refresh1: (secondary display device)
+        60, 75, 85, 100, 120 (default:60)
+
+    viafb_active_dev:
+        This option is used to specify active devices.(CRT, DVI, CRT+LCD...)
+        DVI stands for DVI or HDMI, E.g., If you want to enable HDMI,
+        set viafb_active_dev=DVI. In SAMM case, the previous of
+        viafb_active_dev is primary device, and the following is
+        secondary device.
+
+        For example:
+        To enable one device, such as DVI only, we can use:
+            modprobe viafb viafb_active_dev=DVI
+        To enable two devices, such as CRT+DVI:
+            modprobe viafb viafb_active_dev=CRT+DVI;
+
+        For DuoView case, we can use:
+            modprobe viafb viafb_active_dev=CRT+DVI
+            OR
+            modprobe viafb viafb_active_dev=DVI+CRT...
+
+        For SAMM case:
+        If CRT is primary and DVI is secondary, we should use:
+            modprobe viafb viafb_active_dev=CRT+DVI viafb_SAMM_ON=1...
+        If DVI is primary and CRT is secondary, we should use:
+            modprobe viafb viafb_active_dev=DVI+CRT viafb_SAMM_ON=1...
+
+    viafb_display_hardware_layout:
+        This option is used to specify display hardware layout for CX700 chip.
+        1 : LCD only
+        2 : DVI only
+        3 : LCD+DVI (default)
+        4 : LCD1+LCD2 (internal + internal)
+        16: LCD1+ExternalLCD2 (internal + external)
+
+    viafb_second_size:
+        This option is used to set second device memory size(MB) in SAMM case.
+        The minimal size is 16.
+
+    viafb_platform_epia_dvi:
+        This option is used to enable DVI on EPIA - M
+        0 : No DVI on EPIA - M (default)
+        1 : DVI on EPIA - M
+
+    viafb_bus_width:
+        When using 24 - Bit Bus Width Digital Interface,
+        this option should be set.
+        12: 12-Bit LVDS or 12-Bit TMDS (default)
+        24: 24-Bit LVDS or 24-Bit TMDS
+
+    viafb_device_lcd_dualedge:
+        When using Dual Edge Panel, this option should be set.
+        0 : No Dual Edge Panel (default)
+        1 : Dual Edge Panel
+
+    viafb_video_dev:
+        This option is used to specify video output devices(CRT, DVI, LCD) for
+        duoview case.
+        For example:
+        To output video on DVI, we should use:
+            modprobe viafb viafb_video_dev=DVI...
+
+    viafb_lcd_port:
+        This option is used to specify LCD output port,
+        available values are "DVP0" "DVP1" "DFP_HIGHLOW" "DFP_HIGH" "DFP_LOW".
+        for external LCD + external DVI on CX700(External LCD is on DVP0),
+        we should use:
+            modprobe viafb viafb_lcd_port=DVP0...
+
+Notes:
+    1. CRT may not display properly for DuoView CRT & DVI display at
+       the "640x480" PAL mode with DVI overscan enabled.
+    2. SAMM stands for single adapter multi monitors. It is different from
+       multi-head since SAMM support multi monitor at driver layers, thus fbcon
+       layer doesn't even know about it; SAMM's second screen doesn't have a
+       device node file, thus a user mode application can't access it directly.
+       When SAMM is enabled, viafb_mode and viafb_mode1, viafb_bpp and
+       viafb_bpp1, viafb_refresh and viafb_refresh1 can be different.
+    3. When console is depending on viafbinfo1, dynamically change resolution
+       and bpp, need to call VIAFB specified ioctl interface VIAFB_SET_DEVICE
+       instead of calling common ioctl function FBIOPUT_VSCREENINFO since
+       viafb doesn't support multi-head well, or it will cause screen crush.
+    4. VX800 2D accelerator hasn't been supported in this driver yet. When
+       using driver on VX800, the driver will disable the acceleration
+       function as default.
+
+
+[Configure viafb with "fbset" tool]
+-----------------------------------
+    "fbset" is an inbox utility of Linux.
+    1. Inquire current viafb information, type,
+           # fbset -i
+
+    2. Set various resolutions and viafb_refresh rates,
+           # fbset <resolution-vertical_sync>
+
+       example,
+           # fbset "1024x768-75"
+       or
+           # fbset -g 1024 768 1024 768 32
+       Check the file "/etc/fb.modes" to find display modes available.
+
+    3. Set the color depth,
+           # fbset -depth <value>
+
+       example,
+           # fbset -depth 16
+
+[Bootup with viafb]:
+--------------------
+    Add the following line to your grub.conf:
+    append = "video=viafb:viafb_mode=1024x768,viafb_bpp=32,viafb_refresh=85"
+

Documentation/feature-removal-schedule.txt

@@ -56,30 +56,6 @@ Who:	Mauro Carvalho Chehab <mchehab@infradead.org>
 
 ---------------------------
 
-What:	old tuner-3036 i2c driver
-When:	2.6.28
-Why:	This driver is for VERY old i2c-over-parallel port teletext receiver
-	boxes. Rather then spending effort on converting this driver to V4L2,
-	and since it is extremely unlikely that anyone still uses one of these
-	devices, it was decided to drop it.
-Who:	Hans Verkuil <hverkuil@xs4all.nl>
-	Mauro Carvalho Chehab <mchehab@infradead.org>
-
- ---------------------------
-
-What:   V4L2 dpc7146 driver
-When:   2.6.28
-Why:    Old driver for the dpc7146 demonstration board that is no longer
-	relevant. The last time this was tested on actual hardware was
-	probably around 2002. Since this is a driver for a demonstration
-	board the decision was made to remove it rather than spending a
-	lot of effort continually updating this driver to stay in sync
-	with the latest internal V4L2 or I2C API.
-Who:    Hans Verkuil <hverkuil@xs4all.nl>
-	Mauro Carvalho Chehab <mchehab@infradead.org>
-
----------------------------
-
 What:	PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
 When:	November 2005
 Files:	drivers/pcmcia/: pcmcia_ioctl.c
@@ -144,13 +120,6 @@ Who:	Christoph Hellwig <hch@lst.de>
 
 ---------------------------
 
-What:   eepro100 network driver
-When:   January 2007
-Why:    replaced by the e100 driver
-Who:    Adrian Bunk <bunk@stusta.de>
-
----------------------------
-
 What:	Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 	(temporary transition config option provided until then)
 	The transition config option will also be removed at the same time.
@@ -268,18 +237,6 @@ Who:	Michael Buesch <mb@bu3sch.de>
 
 ---------------------------
 
-What:	init_mm export
-When:	2.6.26
-Why:	Not used in-tree. The current out-of-tree users used it to
-	work around problems in the CPA code which should be resolved
-	by now. One usecase was described to provide verification code
-	of the CPA operation. That's a good idea in general, but such
-	code / infrastructure should be in the kernel and not in some
-	out-of-tree driver.
-Who:	Thomas Gleixner <tglx@linutronix.de>
-
-----------------------------
-
 What:	usedac i386 kernel parameter
 When:	2.6.27
 Why:	replaced by allowdac and no dac combination
@@ -294,6 +251,15 @@ Who:	Jiri Slaby <jirislaby@gmail.com>
 
 ---------------------------
 
+What: print_fn_descriptor_symbol()
+When: October 2009
+Why:  The %pF vsprintf format provides the same functionality in a
+      simpler way.  print_fn_descriptor_symbol() is deprecated but
+      still present to give out-of-tree modules time to change.
+Who:  Bjorn Helgaas <bjorn.helgaas@hp.com>
+
+---------------------------
+
 What:	/sys/o2cb symlink
 When:	January 2010
 Why:	/sys/fs/o2cb is the proper location for this information - /sys/o2cb
@@ -350,3 +316,11 @@ Why:  The 2.6 kernel supports direct writing to ide CD drives, which
       eliminates the need for ide-scsi. The new method is more
       efficient in every way.
 Who:  FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
+
+---------------------------
+
+What:	i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client()
+When:	2.6.29 (ideally) or 2.6.30 (more likely)
+Why:	Deprecated by the new (standard) device driver binding model. Use
+	i2c_driver->probe() and ->remove() instead.
+Who:	Jean Delvare <khali@linux-fr.org>

Documentation/filesystems/Locking

@@ -161,8 +161,12 @@ prototypes:
 	int (*set_page_dirty)(struct page *page);
 	int (*readpages)(struct file *filp, struct address_space *mapping,
 			struct list_head *pages, unsigned nr_pages);
-	int (*prepare_write)(struct file *, struct page *, unsigned, unsigned);
-	int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
+	int (*write_begin)(struct file *, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned flags,
+				struct page **pagep, void **fsdata);
+	int (*write_end)(struct file *, struct address_space *mapping,
+				loff_t pos, unsigned len, unsigned copied,
+				struct page *page, void *fsdata);
 	sector_t (*bmap)(struct address_space *, sector_t);
 	int (*invalidatepage) (struct page *, unsigned long);
 	int (*releasepage) (struct page *, int);
@@ -180,8 +184,6 @@ sync_page:		no	maybe
 writepages:		no
 set_page_dirty		no	no
 readpages:		no
-prepare_write:		no	yes			yes
-commit_write:		no	yes			yes
 write_begin:		no	locks the page		yes
 write_end:		no	yes, unlocks		yes
 perform_write:		no	n/a			yes
@@ -191,7 +193,7 @@ releasepage:		no	yes
 direct_IO:		no
 launder_page:		no	yes
 
-	->prepare_write(), ->commit_write(), ->sync_page() and ->readpage()
+	->write_begin(), ->write_end(), ->sync_page() and ->readpage()
 may be called from the request handler (/dev/loop).
 
 	->readpage() unlocks the page, either synchronously or via I/O

Documentation/filesystems/autofs4-mount-control.txt

@@ -0,0 +1,393 @@
+
+Miscellaneous Device control operations for the autofs4 kernel module
+====================================================================
+
+The problem
+===========
+
+There is a problem with active restarts in autofs (that is to say
+restarting autofs when there are busy mounts).
+
+During normal operation autofs uses a file descriptor opened on the
+directory that is being managed in order to be able to issue control
+operations. Using a file descriptor gives ioctl operations access to
+autofs specific information stored in the super block. The operations
+are things such as setting an autofs mount catatonic, setting the
+expire timeout and requesting expire checks. As is explained below,
+certain types of autofs triggered mounts can end up covering an autofs
+mount itself which prevents us being able to use open(2) to obtain a
+file descriptor for these operations if we don't already have one open.
+
+Currently autofs uses "umount -l" (lazy umount) to clear active mounts
+at restart. While using lazy umount works for most cases, anything that
+needs to walk back up the mount tree to construct a path, such as
+getcwd(2) and the proc file system /proc/<pid>/cwd, no longer works
+because the point from which the path is constructed has been detached
+from the mount tree.
+
+The actual problem with autofs is that it can't reconnect to existing
+mounts. Immediately one thinks of just adding the ability to remount
+autofs file systems would solve it, but alas, that can't work. This is
+because autofs direct mounts and the implementation of "on demand mount
+and expire" of nested mount trees have the file system mounted directly
+on top of the mount trigger directory dentry.
+
+For example, there are two types of automount maps, direct (in the kernel
+module source you will see a third type called an offset, which is just
+a direct mount in disguise) and indirect.
+
+Here is a master map with direct and indirect map entries:
+
+/-      /etc/auto.direct
+/test   /etc/auto.indirect
+
+and the corresponding map files:
+
+/etc/auto.direct:
+
+/automount/dparse/g6  budgie:/autofs/export1
+/automount/dparse/g1  shark:/autofs/export1
+and so on.
+
+/etc/auto.indirect:
+
+g1    shark:/autofs/export1
+g6    budgie:/autofs/export1
+and so on.
+
+For the above indirect map an autofs file system is mounted on /test and
+mounts are triggered for each sub-directory key by the inode lookup
+operation. So we see a mount of shark:/autofs/export1 on /test/g1, for
+example.
+
+The way that direct mounts are handled is by making an autofs mount on
+each full path, such as /automount/dparse/g1, and using it as a mount
+trigger. So when we walk on the path we mount shark:/autofs/export1 "on
+top of this mount point". Since these are always directories we can
+use the follow_link inode operation to trigger the mount.
+
+But, each entry in direct and indirect maps can have offsets (making
+them multi-mount map entries).
+
+For example, an indirect mount map entry could also be:
+
+g1  \
+   /        shark:/autofs/export5/testing/test \
+   /s1      shark:/autofs/export/testing/test/s1 \
+   /s2      shark:/autofs/export5/testing/test/s2 \
+   /s1/ss1  shark:/autofs/export1 \
+   /s2/ss2  shark:/autofs/export2
+
+and a similarly a direct mount map entry could also be:
+
+/automount/dparse/g1 \
+    /       shark:/autofs/export5/testing/test \
+    /s1     shark:/autofs/export/testing/test/s1 \
+    /s2     shark:/autofs/export5/testing/test/s2 \
+    /s1/ss1 shark:/autofs/export2 \
+    /s2/ss2 shark:/autofs/export2
+
+One of the issues with version 4 of autofs was that, when mounting an
+entry with a large number of offsets, possibly with nesting, we needed
+to mount and umount all of the offsets as a single unit. Not really a
+problem, except for people with a large number of offsets in map entries.
+This mechanism is used for the well known "hosts" map and we have seen
+cases (in 2.4) where the available number of mounts are exhausted or
+where the number of privileged ports available is exhausted.
+
+In version 5 we mount only as we go down the tree of offsets and
+similarly for expiring them which resolves the above problem. There is
+somewhat more detail to the implementation but it isn't needed for the
+sake of the problem explanation. The one important detail is that these
+offsets are implemented using the same mechanism as the direct mounts
+above and so the mount points can be covered by a mount.
+
+The current autofs implementation uses an ioctl file descriptor opened
+on the mount point for control operations. The references held by the
+descriptor are accounted for in checks made to determine if a mount is
+in use and is also used to access autofs file system information held
+in the mount super block. So the use of a file handle needs to be
+retained.
+
+
+The Solution
+============
+
+To be able to restart autofs leaving existing direct, indirect and
+offset mounts in place we need to be able to obtain a file handle
+for these potentially covered autofs mount points. Rather than just
+implement an isolated operation it was decided to re-implement the
+existing ioctl interface and add new operations to provide this
+functionality.
+
+In addition, to be able to reconstruct a mount tree that has busy mounts,
+the uid and gid of the last user that triggered the mount needs to be
+available because these can be used as macro substitution variables in
+autofs maps. They are recorded at mount request time and an operation
+has been added to retrieve them.
+
+Since we're re-implementing the control interface, a couple of other
+problems with the existing interface have been addressed. First, when
+a mount or expire operation completes a status is returned to the
+kernel by either a "send ready" or a "send fail" operation. The
+"send fail" operation of the ioctl interface could only ever send
+ENOENT so the re-implementation allows user space to send an actual
+status. Another expensive operation in user space, for those using
+very large maps, is discovering if a mount is present. Usually this
+involves scanning /proc/mounts and since it needs to be done quite
+often it can introduce significant overhead when there are many entries
+in the mount table. An operation to lookup the mount status of a mount
+point dentry (covered or not) has also been added.
+
+Current kernel development policy recommends avoiding the use of the
+ioctl mechanism in favor of systems such as Netlink. An implementation
+using this system was attempted to evaluate its suitability and it was
+found to be inadequate, in this case. The Generic Netlink system was
+used for this as raw Netlink would lead to a significant increase in
+complexity. There's no question that the Generic Netlink system is an
+elegant solution for common case ioctl functions but it's not a complete
+replacement probably because it's primary purpose in life is to be a
+message bus implementation rather than specifically an ioctl replacement.
+While it would be possible to work around this there is one concern
+that lead to the decision to not use it. This is that the autofs
+expire in the daemon has become far to complex because umount
+candidates are enumerated, almost for no other reason than to "count"
+the number of times to call the expire ioctl. This involves scanning
+the mount table which has proved to be a big overhead for users with
+large maps. The best way to improve this is try and get back to the
+way the expire was done long ago. That is, when an expire request is
+issued for a mount (file handle) we should continually call back to
+the daemon until we can't umount any more mounts, then return the
+appropriate status to the daemon. At the moment we just expire one
+mount at a time. A Generic Netlink implementation would exclude this
+possibility for future development due to the requirements of the
+message bus architecture.
+
+
+autofs4 Miscellaneous Device mount control interface
+====================================================
+
+The control interface is opening a device node, typically /dev/autofs.
+
+All the ioctls use a common structure to pass the needed parameter
+information and return operation results:
+
+struct autofs_dev_ioctl {
+	__u32 ver_major;
+	__u32 ver_minor;
+	__u32 size;             /* total size of data passed in
+				 * including this struct */
+	__s32 ioctlfd;          /* automount command fd */
+
+	__u32 arg1;             /* Command parameters */
+	__u32 arg2;
+
+	char path[0];
+};
+
+The ioctlfd field is a mount point file descriptor of an autofs mount
+point. It is returned by the open call and is used by all calls except
+the check for whether a given path is a mount point, where it may
+optionally be used to check a specific mount corresponding to a given
+mount point file descriptor, and when requesting the uid and gid of the
+last successful mount on a directory within the autofs file system.
+
+The fields arg1 and arg2 are used to communicate parameters and results of
+calls made as described below.
+
+The path field is used to pass a path where it is needed and the size field
+is used account for the increased structure length when translating the
+structure sent from user space.
+
+This structure can be initialized before setting specific fields by using
+the void function call init_autofs_dev_ioctl(struct autofs_dev_ioctl *).
+
+All of the ioctls perform a copy of this structure from user space to
+kernel space and return -EINVAL if the size parameter is smaller than
+the structure size itself, -ENOMEM if the kernel memory allocation fails
+or -EFAULT if the copy itself fails. Other checks include a version check
+of the compiled in user space version against the module version and a
+mismatch results in a -EINVAL return. If the size field is greater than
+the structure size then a path is assumed to be present and is checked to
+ensure it begins with a "/" and is NULL terminated, otherwise -EINVAL is
+returned. Following these checks, for all ioctl commands except
+AUTOFS_DEV_IOCTL_VERSION_CMD, AUTOFS_DEV_IOCTL_OPENMOUNT_CMD and
+AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD the ioctlfd is validated and if it is
+not a valid descriptor or doesn't correspond to an autofs mount point
+an error of -EBADF, -ENOTTY or -EINVAL (not an autofs descriptor) is
+returned.
+
+
+The ioctls
+==========
+
+An example of an implementation which uses this interface can be seen
+in autofs version 5.0.4 and later in file lib/dev-ioctl-lib.c of the
+distribution tar available for download from kernel.org in directory
+/pub/linux/daemons/autofs/v5.
+
+The device node ioctl operations implemented by this interface are:
+
+
+AUTOFS_DEV_IOCTL_VERSION
+------------------------
+
+Get the major and minor version of the autofs4 device ioctl kernel module
+implementation. It requires an initialized struct autofs_dev_ioctl as an
+input parameter and sets the version information in the passed in structure.
+It returns 0 on success or the error -EINVAL if a version mismatch is
+detected.
+
+
+AUTOFS_DEV_IOCTL_PROTOVER_CMD and AUTOFS_DEV_IOCTL_PROTOSUBVER_CMD
+------------------------------------------------------------------
+
+Get the major and minor version of the autofs4 protocol version understood
+by loaded module. This call requires an initialized struct autofs_dev_ioctl
+with the ioctlfd field set to a valid autofs mount point descriptor
+and sets the requested version number in structure field arg1. These
+commands return 0 on success or one of the negative error codes if
+validation fails.
+
+
+AUTOFS_DEV_IOCTL_OPENMOUNT and AUTOFS_DEV_IOCTL_CLOSEMOUNT
+----------------------------------------------------------
+
+Obtain and release a file descriptor for an autofs managed mount point
+path. The open call requires an initialized struct autofs_dev_ioctl with
+the the path field set and the size field adjusted appropriately as well
+as the arg1 field set to the device number of the autofs mount. The
+device number can be obtained from the mount options shown in
+/proc/mounts. The close call requires an initialized struct
+autofs_dev_ioct with the ioctlfd field set to the descriptor obtained
+from the open call. The release of the file descriptor can also be done
+with close(2) so any open descriptors will also be closed at process exit.
+The close call is included in the implemented operations largely for
+completeness and to provide for a consistent user space implementation.
+
+
+AUTOFS_DEV_IOCTL_READY_CMD and AUTOFS_DEV_IOCTL_FAIL_CMD
+--------------------------------------------------------
+
+Return mount and expire result status from user space to the kernel.
+Both of these calls require an initialized struct autofs_dev_ioctl
+with the ioctlfd field set to the descriptor obtained from the open
+call and the arg1 field set to the wait queue token number, received
+by user space in the foregoing mount or expire request. The arg2 field
+is set to the status to be returned. For the ready call this is always
+0 and for the fail call it is set to the errno of the operation.
+
+
+AUTOFS_DEV_IOCTL_SETPIPEFD_CMD
+------------------------------
+
+Set the pipe file descriptor used for kernel communication to the daemon.
+Normally this is set at mount time using an option but when reconnecting
+to a existing mount we need to use this to tell the autofs mount about
+the new kernel pipe descriptor. In order to protect mounts against
+incorrectly setting the pipe descriptor we also require that the autofs
+mount be catatonic (see next call).
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call and
+the arg1 field set to descriptor of the pipe. On success the call
+also sets the process group id used to identify the controlling process
+(eg. the owning automount(8) daemon) to the process group of the caller.
+
+
+AUTOFS_DEV_IOCTL_CATATONIC_CMD
+------------------------------
+
+Make the autofs mount point catatonic. The autofs mount will no longer
+issue mount requests, the kernel communication pipe descriptor is released
+and any remaining waits in the queue released.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call.
+
+
+AUTOFS_DEV_IOCTL_TIMEOUT_CMD
+----------------------------
+
+Set the expire timeout for mounts withing an autofs mount point.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call.
+
+
+AUTOFS_DEV_IOCTL_REQUESTER_CMD
+------------------------------
+
+Return the uid and gid of the last process to successfully trigger a the
+mount on the given path dentry.
+
+The call requires an initialized struct autofs_dev_ioctl with the path
+field set to the mount point in question and the size field adjusted
+appropriately as well as the arg1 field set to the device number of the
+containing autofs mount. Upon return the struct field arg1 contains the
+uid and arg2 the gid.
+
+When reconstructing an autofs mount tree with active mounts we need to
+re-connect to mounts that may have used the original process uid and
+gid (or string variations of them) for mount lookups within the map entry.
+This call provides the ability to obtain this uid and gid so they may be
+used by user space for the mount map lookups.
+
+
+AUTOFS_DEV_IOCTL_EXPIRE_CMD
+---------------------------
+
+Issue an expire request to the kernel for an autofs mount. Typically
+this ioctl is called until no further expire candidates are found.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call. In
+addition an immediate expire, independent of the mount timeout, can be
+requested by setting the arg1 field to 1. If no expire candidates can
+be found the ioctl returns -1 with errno set to EAGAIN.
+
+This call causes the kernel module to check the mount corresponding
+to the given ioctlfd for mounts that can be expired, issues an expire
+request back to the daemon and waits for completion.
+
+AUTOFS_DEV_IOCTL_ASKUMOUNT_CMD
+------------------------------
+
+Checks if an autofs mount point is in use.
+
+The call requires an initialized struct autofs_dev_ioctl with the
+ioctlfd field set to the descriptor obtained from the open call and
+it returns the result in the arg1 field, 1 for busy and 0 otherwise.
+
+
+AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD
+---------------------------------
+
+Check if the given path is a mountpoint.
+
+The call requires an initialized struct autofs_dev_ioctl. There are two
+possible variations. Both use the path field set to the path of the mount
+point to check and the size field adjusted appropriately. One uses the
+ioctlfd field to identify a specific mount point to check while the other
+variation uses the path and optionaly arg1 set to an autofs mount type.
+The call returns 1 if this is a mount point and sets arg1 to the device
+number of the mount and field arg2 to the relevant super block magic
+number (described below) or 0 if it isn't a mountpoint. In both cases
+the the device number (as returned by new_encode_dev()) is returned
+in field arg1.
+
+If supplied with a file descriptor we're looking for a specific mount,
+not necessarily at the top of the mounted stack. In this case the path
+the descriptor corresponds to is considered a mountpoint if it is itself
+a mountpoint or contains a mount, such as a multi-mount without a root
+mount. In this case we return 1 if the descriptor corresponds to a mount
+point and and also returns the super magic of the covering mount if there
+is one or 0 if it isn't a mountpoint.
+
+If a path is supplied (and the ioctlfd field is set to -1) then the path
+is looked up and is checked to see if it is the root of a mount. If a
+type is also given we are looking for a particular autofs mount and if
+a match isn't found a fail is returned. If the the located path is the
+root of a mount 1 is returned along with the super magic of the mount
+or 0 otherwise.
+

Documentation/filesystems/ext3.txt

@@ -96,6 +96,11 @@ errors=remount-ro(*)	Remount the filesystem read-only on an error.
 errors=continue		Keep going on a filesystem error.
 errors=panic		Panic and halt the machine if an error occurs.
 
+data_err=ignore(*)	Just print an error message if an error occurs
+			in a file data buffer in ordered mode.
+data_err=abort		Abort the journal if an error occurs in a file
+			data buffer in ordered mode.
+
 grpid			Give objects the same group ID as their creator.
 bsdgroups
 
@@ -193,6 +198,5 @@ kernel source:	<file:fs/ext3/>
 programs: 	http://e2fsprogs.sourceforge.net/
 		http://ext2resize.sourceforge.net
 
-useful links:	http://www.zip.com.au/~akpm/linux/ext3/ext3-usage.html
-		http://www-106.ibm.com/developerworks/linux/library/l-fs7/
+useful links:	http://www-106.ibm.com/developerworks/linux/library/l-fs7/
 		http://www-106.ibm.com/developerworks/linux/library/l-fs8/

Documentation/filesystems/ext4.txt

@@ -2,19 +2,24 @@
 Ext4 Filesystem
 ===============
 
-This is a development version of the ext4 filesystem, an advanced level
-of the ext3 filesystem which incorporates scalability and reliability
-enhancements for supporting large filesystems (64 bit) in keeping with
-increasing disk capacities and state-of-the-art feature requirements.
+Ext4 is an an advanced level of the ext3 filesystem which incorporates
+scalability and reliability enhancements for supporting large filesystems
+(64 bit) in keeping with increasing disk capacities and state-of-the-art
+feature requirements.
 
-Mailing list: linux-ext4@vger.kernel.org
+Mailing list:	linux-ext4@vger.kernel.org
+Web site:	http://ext4.wiki.kernel.org
 
 
 1. Quick usage instructions:
 ===========================
 
+Note: More extensive information for getting started with ext4 can be
+      found at the ext4 wiki site at the URL:
+      http://ext4.wiki.kernel.org/index.php/Ext4_Howto
+
   - Compile and install the latest version of e2fsprogs (as of this
-    writing version 1.41) from:
+    writing version 1.41.3) from:
 
     http://sourceforge.net/project/showfiles.php?group_id=2406
 	
@@ -36,11 +41,9 @@ Mailing list: linux-ext4@vger.kernel.org
 
     	# mke2fs -t ext4 /dev/hda1
 
-    Or configure an existing ext3 filesystem to support extents and set
-    the test_fs flag to indicate that it's ok for an in-development
-    filesystem to touch this filesystem:
+    Or to configure an existing ext3 filesystem to support extents: 
 
-	# tune2fs -O extents -E test_fs /dev/hda1
+	# tune2fs -O extents /dev/hda1
 
     If the filesystem was created with 128 byte inodes, it can be
     converted to use 256 byte for greater efficiency via:
@@ -104,8 +107,8 @@ exist yet so I'm not sure they're in the near-term roadmap.
 The big performance win will come with mballoc, delalloc and flex_bg
 grouping of bitmaps and inode tables.  Some test results available here:
 
- - http://www.bullopensource.org/ext4/20080530/ffsb-write-2.6.26-rc2.html
- - http://www.bullopensource.org/ext4/20080530/ffsb-readwrite-2.6.26-rc2.html
+ - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-write-2.6.27-rc1.html
+ - http://www.bullopensource.org/ext4/20080818-ffsb/ffsb-readwrite-2.6.27-rc1.html
 
 3. Options
 ==========
@@ -214,9 +217,6 @@ noreservation
 bsddf		(*)	Make 'df' act like BSD.
 minixdf			Make 'df' act like Minix.
 
-check=none		Don't do extra checking of bitmaps on mount.
-nocheck
-
 debug			Extra debugging information is sent to syslog.
 
 errors=remount-ro(*)	Remount the filesystem read-only on an error.
@@ -253,8 +253,6 @@ nobh			(a) cache disk block mapping information
 			"nobh" option tries to avoid associating buffer
 			heads (supported only for "writeback" mode).
 
-mballoc		(*)	Use the multiple block allocator for block allocation
-nomballoc		disabled multiple block allocator for block allocation.
 stripe=n		Number of filesystem blocks that mballoc will try
 			to use for allocation size and alignment. For RAID5/6
 			systems this should be the number of data

Documentation/filesystems/nfsroot.txt

@@ -169,7 +169,7 @@ They depend on various facilities being available:
 3.1)  Booting from a floppy using syslinux
 
 	When building kernels, an easy way to create a boot floppy that uses
-	syslinux is to use the zdisk or bzdisk make targets which use
+	syslinux is to use the zdisk or bzdisk make targets which use zimage
       	and bzimage images respectively. Both targets accept the
      	FDARGS parameter which can be used to set the kernel command line.
 

Documentation/filesystems/ocfs2.txt

@@ -28,10 +28,7 @@ Manish Singh  <manish.singh@oracle.com>
 Caveats
 =======
 Features which OCFS2 does not support yet:
-	- extended attributes
 	- quotas
-	- cluster aware flock
-	- cluster aware lockf
 	- Directory change notification (F_NOTIFY)
 	- Distributed Caching (F_SETLEASE/F_GETLEASE/break_lease)
 	- POSIX ACLs

Documentation/filesystems/proc.txt

@@ -44,6 +44,7 @@ Table of Contents
   2.14	/proc/<pid>/io - Display the IO accounting fields
   2.15	/proc/<pid>/coredump_filter - Core dump filtering settings
   2.16	/proc/<pid>/mountinfo - Information about mounts
+  2.17	/proc/sys/fs/epoll - Configuration options for the epoll interface
 
 ------------------------------------------------------------------------------
 Preface
@@ -1321,15 +1322,30 @@ debugging information is displayed on console.
 NMI switch that most IA32 servers have fires unknown NMI up, for example.
 If a system hangs up, try pressing the NMI switch.
 
+panic_on_unrecovered_nmi
+------------------------
+
+The default Linux behaviour on an NMI of either memory or unknown is to continue
+operation. For many environments such as scientific computing it is preferable
+that the box is taken out and the error dealt with than an uncorrected
+parity/ECC error get propogated.
+
+A small number of systems do generate NMI's for bizarre random reasons such as
+power management so the default is off. That sysctl works like the existing
+panic controls already in that directory.
+
 nmi_watchdog
 ------------
 
 Enables/Disables the NMI watchdog on x86 systems.  When the value is non-zero
 the NMI watchdog is enabled and will continuously test all online cpus to
-determine whether or not they are still functioning properly.
+determine whether or not they are still functioning properly. Currently,
+passing "nmi_watchdog=" parameter at boot time is required for this function
+to work.
 
-Because the NMI watchdog shares registers with oprofile, by disabling the NMI
-watchdog, oprofile may have more registers to utilize.
+If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the
+NMI watchdog shares registers with oprofile. By disabling the NMI watchdog,
+oprofile may have more registers to utilize.
 
 msgmni
 ------
@@ -1372,15 +1388,18 @@ causes the kernel to prefer to reclaim dentries and inodes.
 dirty_background_ratio
 ----------------------
 
-Contains, as a percentage of total system memory, the number of pages at which
-the pdflush background writeback daemon will start writing out dirty data.
+Contains, as a percentage of the dirtyable system memory (free pages + mapped
+pages + file cache, not including locked pages and HugePages), the number of
+pages at which the pdflush background writeback daemon will start writing out
+dirty data.
 
 dirty_ratio
 -----------------
 
-Contains, as a percentage of total system memory, the number of pages at which
-a process which is generating disk writes will itself start writing out dirty
-data.
+Contains, as a percentage of the dirtyable system memory (free pages + mapped
+pages + file cache, not including locked pages and HugePages), the number of
+pages at which a process which is generating disk writes will itself start
+writing out dirty data.
 
 dirty_writeback_centisecs
 -------------------------
@@ -2400,24 +2419,29 @@ will be dumped when the <pid> process is dumped. coredump_filter is a bitmask
 of memory types. If a bit of the bitmask is set, memory segments of the
 corresponding memory type are dumped, otherwise they are not dumped.
 
-The following 4 memory types are supported:
+The following 7 memory types are supported:
   - (bit 0) anonymous private memory
   - (bit 1) anonymous shared memory
   - (bit 2) file-backed private memory
   - (bit 3) file-backed shared memory
   - (bit 4) ELF header pages in file-backed private memory areas (it is
             effective only if the bit 2 is cleared)
+  - (bit 5) hugetlb private memory
+  - (bit 6) hugetlb shared memory
 
   Note that MMIO pages such as frame buffer are never dumped and vDSO pages
   are always dumped regardless of the bitmask status.
 
-Default value of coredump_filter is 0x3; this means all anonymous memory
-segments are dumped.
+  Note bit 0-4 doesn't effect any hugetlb memory. hugetlb memory are only
+  effected by bit 5-6.
+
+Default value of coredump_filter is 0x23; this means all anonymous memory
+segments and hugetlb private memory are dumped.
 
 If you don't want to dump all shared memory segments attached to pid 1234,
-write 1 to the process's proc file.
+write 0x21 to the process's proc file.
 
-  $ echo 0x1 > /proc/1234/coredump_filter
+  $ echo 0x21 > /proc/1234/coredump_filter
 
 When a new process is created, the process inherits the bitmask status from its
 parent. It is useful to set up coredump_filter before the program runs.
@@ -2463,4 +2487,30 @@ For more information on mount propagation see:
 
   Documentation/filesystems/sharedsubtree.txt
 
+2.17	/proc/sys/fs/epoll - Configuration options for the epoll interface
+--------------------------------------------------------
+
+This directory contains configuration options for the epoll(7) interface.
+
+max_user_instances
+------------------
+
+This is the maximum number of epoll file descriptors that a single user can
+have open at a given time. The default value is 128, and should be enough
+for normal users.
+
+max_user_watches
+----------------
+
+Every epoll file descriptor can store a number of files to be monitored
+for event readiness. Each one of these monitored files constitutes a "watch".
+This configuration option sets the maximum number of "watches" that are
+allowed for each user.
+Each "watch" costs roughly 90 bytes on a 32bit kernel, and roughly 160 bytes
+on a 64bit one.
+The current default value for  max_user_watches  is the 1/32 of the available
+low memory, divided for the "watch" cost in bytes.
+
+
 ------------------------------------------------------------------------------
+

Documentation/filesystems/ramfs-rootfs-initramfs.txt

@@ -130,12 +130,12 @@ The 2.6 kernel build process always creates a gzipped cpio format initramfs
 archive and links it into the resulting kernel binary.  By default, this
 archive is empty (consuming 134 bytes on x86).
 
-The config option CONFIG_INITRAMFS_SOURCE (for some reason buried under
-devices->block devices in menuconfig, and living in usr/Kconfig) can be used
-to specify a source for the initramfs archive, which will automatically be
-incorporated into the resulting binary.  This option can point to an existing
-gzipped cpio archive, a directory containing files to be archived, or a text
-file specification such as the following example:
+The config option CONFIG_INITRAMFS_SOURCE (in General Setup in menuconfig,
+and living in usr/Kconfig) can be used to specify a source for the
+initramfs archive, which will automatically be incorporated into the
+resulting binary.  This option can point to an existing gzipped cpio
+archive, a directory containing files to be archived, or a text file
+specification such as the following example:
 
   dir /dev 755 0 0
   nod /dev/console 644 0 0 c 5 1
@@ -263,7 +263,7 @@ User Mode Linux, like so:
     sleep(999999999);
   }
   EOF
-  gcc -static hello2.c -o init
+  gcc -static hello.c -o init
   echo init | cpio -o -H newc | gzip > test.cpio.gz
   # Testing external initramfs using the initrd loading mechanism.
   qemu -kernel /boot/vmlinuz -initrd test.cpio.gz /dev/zero

Documentation/filesystems/ubifs.txt

@@ -86,6 +86,15 @@ norm_unmount (*)	commit on unmount; the journal is committed
 fast_unmount		do not commit on unmount; this option makes
 			unmount faster, but the next mount slower
 			because of the need to replay the journal.
+bulk_read		read more in one go to take advantage of flash
+			media that read faster sequentially
+no_bulk_read (*)	do not bulk-read
+no_chk_data_crc		skip checking of CRCs on data nodes in order to
+			improve read performance. Use this option only
+			if the flash media is highly reliable. The effect
+			of this option is that corruption of the contents
+			of a file can go unnoticed.
+chk_data_crc (*)	do not skip checking CRCs on data nodes
 
 
 Quick usage instructions

Documentation/filesystems/vfat.txt

@@ -8,6 +8,12 @@ if you want to format from within Linux.
 
 VFAT MOUNT OPTIONS
 ----------------------------------------------------------------------
+uid=###       -- Set the owner of all files on this filesystem.
+		 The default is the uid of current process.
+
+gid=###       -- Set the group of all files on this filesystem.
+		 The default is the gid of current process.
+
 umask=###     -- The permission mask (for files and directories, see umask(1)).
                  The default is the umask of current process.
 
@@ -36,7 +42,7 @@ codepage=###  -- Sets the codepage number for converting to shortname
 		 characters on FAT filesystem.
 		 By default, FAT_DEFAULT_CODEPAGE setting is used.
 
-iocharset=name -- Character set to use for converting between the
+iocharset=<name> -- Character set to use for converting between the
 		 encoding is used for user visible filename and 16 bit
 		 Unicode characters. Long filenames are stored on disk
 		 in Unicode format, but Unix for the most part doesn't
@@ -86,6 +92,8 @@ check=s|r|n   -- Case sensitivity checking setting.
                  r: relaxed, case insensitive
                  n: normal, default setting, currently case insensitive
 
+nocase        -- This was deprecated for vfat. Use shortname=win95 instead.
+
 shortname=lower|win95|winnt|mixed
 	      -- Shortname display/create setting.
 		 lower: convert to lowercase for display,
@@ -99,11 +107,31 @@ shortname=lower|win95|winnt|mixed
 tz=UTC        -- Interpret timestamps as UTC rather than local time.
                  This option disables the conversion of timestamps
                  between local time (as used by Windows on FAT) and UTC
-                 (which Linux uses internally).  This is particuluarly
+                 (which Linux uses internally).  This is particularly
                  useful when mounting devices (like digital cameras)
                  that are set to UTC in order to avoid the pitfalls of
                  local time.
 
+showexec      -- If set, the execute permission bits of the file will be
+		 allowed only if the extension part of the name is .EXE,
+		 .COM, or .BAT. Not set by default.
+
+debug         -- Can be set, but unused by the current implementation.
+
+sys_immutable -- If set, ATTR_SYS attribute on FAT is handled as
+		 IMMUTABLE flag on Linux. Not set by default.
+
+flush         -- If set, the filesystem will try to flush to disk more
+		 early than normal. Not set by default.
+
+rodir	      -- FAT has the ATTR_RO (read-only) attribute. But on Windows,
+		 the ATTR_RO of the directory will be just ignored actually,
+		 and is used by only applications as flag. E.g. it's setted
+		 for the customized folder.
+
+		 If you want to use ATTR_RO as read-only flag even for
+		 the directory, set this option.
+
 <bool>: 0,1,yes,no,true,false
 
 TODO

Documentation/filesystems/vfs.txt

@@ -492,7 +492,7 @@ written-back to storage typically in whole pages, however the
 address_space has finer control of write sizes.
 
 The read process essentially only requires 'readpage'.  The write
-process is more complicated and uses prepare_write/commit_write or
+process is more complicated and uses write_begin/write_end or
 set_page_dirty to write data into the address_space, and writepage,
 sync_page, and writepages to writeback data to storage.
 
@@ -521,8 +521,6 @@ struct address_space_operations {
 	int (*set_page_dirty)(struct page *page);
 	int (*readpages)(struct file *filp, struct address_space *mapping,
 			struct list_head *pages, unsigned nr_pages);
-	int (*prepare_write)(struct file *, struct page *, unsigned, unsigned);
-	int (*commit_write)(struct file *, struct page *, unsigned, unsigned);
 	int (*write_begin)(struct file *, struct address_space *mapping,
 				loff_t pos, unsigned len, unsigned flags,
 				struct page **pagep, void **fsdata);
@@ -598,37 +596,7 @@ struct address_space_operations {
 	readpages is only used for read-ahead, so read errors are
   	ignored.  If anything goes wrong, feel free to give up.
 
-  prepare_write: called by the generic write path in VM to set up a write
-  	request for a page.  This indicates to the address space that
-  	the given range of bytes is about to be written.  The
-  	address_space should check that the write will be able to
-  	complete, by allocating space if necessary and doing any other
-  	internal housekeeping.  If the write will update parts of
-  	any basic-blocks on storage, then those blocks should be
-  	pre-read (if they haven't been read already) so that the
-  	updated blocks can be written out properly.
-	The page will be locked.
-
-	Note: the page _must not_ be marked uptodate in this function
-	(or anywhere else) unless it actually is uptodate right now. As
-	soon as a page is marked uptodate, it is possible for a concurrent
-	read(2) to copy it to userspace.
-
-  commit_write: If prepare_write succeeds, new data will be copied
-        into the page and then commit_write will be called.  It will
-        typically update the size of the file (if appropriate) and
-        mark the inode as dirty, and do any other related housekeeping
-        operations.  It should avoid returning an error if possible -
-        errors should have been handled by prepare_write.
-
-  write_begin: This is intended as a replacement for prepare_write. The
-	key differences being that:
-		- it returns a locked page (in *pagep) rather than being
-		  given a pre locked page;
-		- it must be able to cope with short writes (where the
-		  length passed to write_begin is greater than the number
-		  of bytes copied into the page).
-
+  write_begin:
 	Called by the generic buffered write code to ask the filesystem to
 	prepare to write len bytes at the given offset in the file. The
 	address_space should check that the write will be able to complete,
@@ -640,6 +608,9 @@ struct address_space_operations {
         The filesystem must return the locked pagecache page for the specified
 	offset, in *pagep, for the caller to write into.
 
+	It must be able to cope with short writes (where the length passed to
+	write_begin is greater than the number of bytes copied into the page).
+
 	flags is a field for AOP_FLAG_xxx flags, described in
 	include/linux/fs.h.
 

Documentation/filesystems/xfs.txt

@@ -229,10 +229,6 @@ The following sysctls are available for the XFS filesystem:
 	ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl
 	is set.
 
-  fs.xfs.restrict_chown		(Min: 0  Default: 1  Max: 1)
-  	Controls whether unprivileged users can use chown to "give away"
-	a file to another user.
-
   fs.xfs.inherit_sync		(Min: 0  Default: 1  Max: 1)
 	Setting this to "1" will cause the "sync" flag set
 	by the xfs_io(8) chattr command on a directory to be