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Merge git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6

* git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-2.6:
  sysfs: fix off-by-one error in fill_read_buffer()
  kobject: two typo fixes
  UIO: add UIO documentation target to DocBook Makefile
  UIO: fix up the UIO documentation
  create /sys/.../power when CONFIG_PM is set
  allow LEGACY_PTYS to be set to 0
Linus Torvalds 17 年之前
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cae2f9c46d

+ 1 - 1
Documentation/DocBook/Makefile

@@ -11,7 +11,7 @@ DOCBOOKS := wanbook.xml z8530book.xml mcabook.xml videobook.xml \
 	    procfs-guide.xml writing_usb_driver.xml \
 	    kernel-api.xml filesystems.xml lsm.xml usb.xml \
 	    gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \
-	    genericirq.xml s390-drivers.xml
+	    genericirq.xml s390-drivers.xml uio-howto.xml
 
 ###
 # The build process is as follows (targets):

+ 32 - 58
Documentation/DocBook/uio-howto.tmpl

@@ -29,6 +29,12 @@
 </abstract>
 
 <revhistory>
+	<revision>
+	<revnumber>0.4</revnumber>
+	<date>2007-11-26</date>
+	<authorinitials>hjk</authorinitials>
+	<revremark>Removed section about uio_dummy.</revremark>
+	</revision>
 	<revision>
 	<revnumber>0.3</revnumber>
 	<date>2007-04-29</date>
@@ -94,6 +100,26 @@ interested in translating it, please email me
 	user space. This simplifies development and reduces the risk of
 	serious bugs within a kernel module.
 	</para>
+	<para>
+	Please note that UIO is not an universal driver interface. Devices
+	that are already handled well by other kernel subsystems (like
+	networking or serial or USB) are no candidates for an UIO driver.
+	Hardware that is ideally suited for an UIO driver fulfills all of
+	the following:
+	</para>
+<itemizedlist>
+<listitem>
+	<para>The device has memory that can be mapped. The device can be
+	controlled completely by writing to this memory.</para>
+</listitem>
+<listitem>
+	<para>The device usually generates interrupts.</para>
+</listitem>
+<listitem>
+	<para>The device does not fit into one of the standard kernel
+	subsystems.</para>
+</listitem>
+</itemizedlist>
 </sect1>
 
 <sect1 id="thanks">
@@ -174,8 +200,9 @@ interested in translating it, please email me
 	For cards that don't generate interrupts but need to be
 	polled, there is the possibility to set up a timer that
 	triggers the interrupt handler at configurable time intervals.
-	See <filename>drivers/uio/uio_dummy.c</filename> for an
-	example of this technique.
+	This interrupt simulation is done by calling
+	<function>uio_event_notify()</function>
+	from the timer's event handler.
 	</para>
 
 	<para>
@@ -263,63 +290,11 @@ offset = N * getpagesize();
 </sect1>
 </chapter>
 
-<chapter id="using-uio_dummy" xreflabel="Using uio_dummy">
-<?dbhtml filename="using-uio_dummy.html"?>
-<title>Using uio_dummy</title>
-	<para>
-	Well, there is no real use for uio_dummy. Its only purpose is
-	to test most parts of the UIO system (everything except
-	hardware interrupts), and to serve as an example for the
-	kernel module that you will have to write yourself.
-	</para>
-
-<sect1 id="what_uio_dummy_does">
-<title>What uio_dummy does</title>
-	<para>
-	The kernel module <filename>uio_dummy.ko</filename> creates a
-	device that uses a timer to generate periodic interrupts. The
-	interrupt handler does nothing but increment a counter. The
-	driver adds two custom attributes, <varname>count</varname>
-	and <varname>freq</varname>, that appear under
-	<filename>/sys/devices/platform/uio_dummy/</filename>.
-	</para>
-
-	<para>
-	The attribute <varname>count</varname> can be read and
-	written.  The associated file
-	<filename>/sys/devices/platform/uio_dummy/count</filename>
-	appears as a normal text file and contains the total number of
-	timer interrupts. If you look at it (e.g. using
-	<function>cat</function>), you'll notice it is slowly counting
-	up.
-	</para>
-
-	<para>
-	The attribute <varname>freq</varname> can be read and written.
-	The content of
-	<filename>/sys/devices/platform/uio_dummy/freq</filename>
-	represents the number of system timer ticks between two timer
-	interrupts. The default value of <varname>freq</varname> is
-	the value of the kernel variable <varname>HZ</varname>, which
-	gives you an interval of one second. Lower values will
-	increase the frequency. Try the following:
-	</para>
-<programlisting format="linespecific">
-cd /sys/devices/platform/uio_dummy/
-echo 100 > freq
-</programlisting>
-	<para>
-	Use <function>cat count</function> to see how the interrupt
-	frequency changes.
-	</para>
-</sect1>
-</chapter>
-
 <chapter id="custom_kernel_module" xreflabel="Writing your own kernel module">
 <?dbhtml filename="custom_kernel_module.html"?>
 <title>Writing your own kernel module</title>
 	<para>
-	Please have a look at <filename>uio_dummy.c</filename> as an
+	Please have a look at <filename>uio_cif.c</filename> as an
 	example. The following paragraphs explain the different
 	sections of this file.
 	</para>
@@ -354,9 +329,8 @@ See the description below for details.
 interrupt, it's your modules task to determine the irq number during
 initialization. If you don't have a hardware generated interrupt but
 want to trigger the interrupt handler in some other way, set
-<varname>irq</varname> to <varname>UIO_IRQ_CUSTOM</varname>. The
-uio_dummy module does this as it triggers the event mechanism in a timer
-routine. If you had no interrupt at all, you could set
+<varname>irq</varname> to <varname>UIO_IRQ_CUSTOM</varname>.
+If you had no interrupt at all, you could set
 <varname>irq</varname> to <varname>UIO_IRQ_NONE</varname>, though this
 rarely makes sense.
 </para></listitem>

+ 3 - 1
drivers/base/core.c

@@ -770,9 +770,10 @@ int device_add(struct device *dev)
 	error = device_add_attrs(dev);
 	if (error)
 		goto AttrsError;
-	error = device_pm_add(dev);
+	error = dpm_sysfs_add(dev);
 	if (error)
 		goto PMError;
+	device_pm_add(dev);
 	error = bus_add_device(dev);
 	if (error)
 		goto BusError;
@@ -797,6 +798,7 @@ int device_add(struct device *dev)
 	return error;
  BusError:
 	device_pm_remove(dev);
+	dpm_sysfs_remove(dev);
  PMError:
 	if (dev->bus)
 		blocking_notifier_call_chain(&dev->bus->bus_notifier,

+ 2 - 1
drivers/base/power/Makefile

@@ -1,5 +1,6 @@
 obj-y			:= shutdown.o
-obj-$(CONFIG_PM_SLEEP)	+= main.o sysfs.o
+obj-$(CONFIG_PM)	+= sysfs.o
+obj-$(CONFIG_PM_SLEEP)	+= main.o
 obj-$(CONFIG_PM_TRACE)	+= trace.o
 
 ifeq ($(CONFIG_DEBUG_DRIVER),y)

+ 1 - 7
drivers/base/power/main.c

@@ -38,20 +38,14 @@ static DEFINE_MUTEX(dpm_list_mtx);
 int (*platform_enable_wakeup)(struct device *dev, int is_on);
 
 
-int device_pm_add(struct device *dev)
+void device_pm_add(struct device *dev)
 {
-	int error;
-
 	pr_debug("PM: Adding info for %s:%s\n",
 		 dev->bus ? dev->bus->name : "No Bus",
 		 kobject_name(&dev->kobj));
 	mutex_lock(&dpm_list_mtx);
 	list_add_tail(&dev->power.entry, &dpm_active);
-	error = dpm_sysfs_add(dev);
-	if (error)
-		list_del(&dev->power.entry);
 	mutex_unlock(&dpm_list_mtx);
-	return error;
 }
 
 void device_pm_remove(struct device *dev)

+ 21 - 7
drivers/base/power/power.h

@@ -13,14 +13,29 @@ extern void device_shutdown(void);
 
 extern struct list_head dpm_active;	/* The active device list */
 
-static inline struct device * to_device(struct list_head * entry)
+static inline struct device *to_device(struct list_head *entry)
 {
 	return container_of(entry, struct device, power.entry);
 }
 
-extern int device_pm_add(struct device *);
+extern void device_pm_add(struct device *);
 extern void device_pm_remove(struct device *);
 
+#else /* CONFIG_PM_SLEEP */
+
+
+static inline void device_pm_add(struct device *dev)
+{
+}
+
+static inline void device_pm_remove(struct device *dev)
+{
+}
+
+#endif
+
+#ifdef CONFIG_PM
+
 /*
  * sysfs.c
  */
@@ -28,16 +43,15 @@ extern void device_pm_remove(struct device *);
 extern int dpm_sysfs_add(struct device *);
 extern void dpm_sysfs_remove(struct device *);
 
-#else /* CONFIG_PM_SLEEP */
-
+#else /* CONFIG_PM */
 
-static inline int device_pm_add(struct device * dev)
+static inline int dpm_sysfs_add(struct device *dev)
 {
 	return 0;
 }
-static inline void device_pm_remove(struct device * dev)
-{
 
+static inline void dpm_sysfs_remove(struct device *dev)
+{
 }
 
 #endif

+ 1 - 1
drivers/char/Kconfig

@@ -457,7 +457,7 @@ config LEGACY_PTYS
 config LEGACY_PTY_COUNT
 	int "Maximum number of legacy PTY in use"
 	depends on LEGACY_PTYS
-	range 1 256
+	range 0 256
 	default "256"
 	---help---
 	  The maximum number of legacy PTYs that can be used at any one time.

+ 5 - 1
fs/sysfs/file.c

@@ -119,7 +119,11 @@ static int fill_read_buffer(struct dentry * dentry, struct sysfs_buffer * buffer
 
 	sysfs_put_active_two(attr_sd);
 
-	BUG_ON(count > (ssize_t)PAGE_SIZE);
+	/*
+	 * The code works fine with PAGE_SIZE return but it's likely to
+	 * indicate truncated result or overflow in normal use cases.
+	 */
+	BUG_ON(count >= (ssize_t)PAGE_SIZE);
 	if (count >= 0) {
 		buffer->needs_read_fill = 0;
 		buffer->count = count;

+ 2 - 2
lib/kobject.c

@@ -313,8 +313,8 @@ int kobject_rename(struct kobject * kobj, const char *new_name)
 		struct kobject *temp_kobj;
 		temp_kobj = kset_find_obj(kobj->kset, new_name);
 		if (temp_kobj) {
-			printk(KERN_WARNING "kobject '%s' can not be renamed "
-			       "to '%s' as '%s' is already in existance.\n",
+			printk(KERN_WARNING "kobject '%s' cannot be renamed "
+			       "to '%s' as '%s' is already in existence.\n",
 			       kobject_name(kobj), new_name, new_name);
 			kobject_put(temp_kobj);
 			return -EINVAL;