feature-removal-schedule.txt 13 KB

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  1. The following is a list of files and features that are going to be
  2. removed in the kernel source tree. Every entry should contain what
  3. exactly is going away, why it is happening, and who is going to be doing
  4. the work. When the feature is removed from the kernel, it should also
  5. be removed from this file.
  6. ---------------------------
  7. What: MXSER
  8. When: December 2007
  9. Why: Old mxser driver is obsoleted by the mxser_new. Give it some time yet
  10. and remove it.
  11. Who: Jiri Slaby <jirislaby@gmail.com>
  12. ---------------------------
  13. What: V4L2 VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP
  14. When: October 2007
  15. Why: Broken attempt to set MPEG compression parameters. These ioctls are
  16. not able to implement the wide variety of parameters that can be set
  17. by hardware MPEG encoders. A new MPEG control mechanism was created
  18. in kernel 2.6.18 that replaces these ioctls. See the V4L2 specification
  19. (section 1.9: Extended controls) for more information on this topic.
  20. Who: Hans Verkuil <hverkuil@xs4all.nl> and
  21. Mauro Carvalho Chehab <mchehab@infradead.org>
  22. ---------------------------
  23. What: /sys/devices/.../power/state
  24. dev->power.power_state
  25. dpm_runtime_{suspend,resume)()
  26. When: July 2007
  27. Why: Broken design for runtime control over driver power states, confusing
  28. driver-internal runtime power management with: mechanisms to support
  29. system-wide sleep state transitions; event codes that distinguish
  30. different phases of swsusp "sleep" transitions; and userspace policy
  31. inputs. This framework was never widely used, and most attempts to
  32. use it were broken. Drivers should instead be exposing domain-specific
  33. interfaces either to kernel or to userspace.
  34. Who: Pavel Machek <pavel@suse.cz>
  35. ---------------------------
  36. What: RAW driver (CONFIG_RAW_DRIVER)
  37. When: December 2005
  38. Why: declared obsolete since kernel 2.6.3
  39. O_DIRECT can be used instead
  40. Who: Adrian Bunk <bunk@stusta.de>
  41. ---------------------------
  42. What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  43. When: June 2007
  44. Why: Deprecated in favour of the more efficient and robust rawiso interface.
  45. Affected are applications which use the deprecated part of libraw1394
  46. (raw1394_iso_write, raw1394_start_iso_write, raw1394_start_iso_rcv,
  47. raw1394_stop_iso_rcv) or bypass libraw1394.
  48. Who: Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>
  49. ---------------------------
  50. What: old NCR53C9x driver
  51. When: October 2007
  52. Why: Replaced by the much better esp_scsi driver. Actual low-level
  53. driver can ported over almost trivially.
  54. Who: David Miller <davem@davemloft.net>
  55. Christoph Hellwig <hch@lst.de>
  56. ---------------------------
  57. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  58. When: December 2006
  59. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  60. series. The old API have lots of drawbacks and don't provide enough
  61. means to work with all video and audio standards. The newer API is
  62. already available on the main drivers and should be used instead.
  63. Newer drivers should use v4l_compat_translate_ioctl function to handle
  64. old calls, replacing to newer ones.
  65. Decoder iocts are using internally to allow video drivers to
  66. communicate with video decoders. This should also be improved to allow
  67. V4L2 calls being translated into compatible internal ioctls.
  68. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  69. ---------------------------
  70. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  71. When: November 2005
  72. Files: drivers/pcmcia/: pcmcia_ioctl.c
  73. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  74. normal hotpluggable bus, and with it using the default kernel
  75. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  76. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  77. unnecessary, and makes further cleanups and integration of the
  78. PCMCIA subsystem into the Linux kernel device driver model more
  79. difficult. The features provided by cardmgr and cardctl are either
  80. handled by the kernel itself now or are available in the new
  81. pcmciautils package available at
  82. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  83. Who: Dominik Brodowski <linux@brodo.de>
  84. ---------------------------
  85. What: remove EXPORT_SYMBOL(kernel_thread)
  86. When: August 2006
  87. Files: arch/*/kernel/*_ksyms.c
  88. Why: kernel_thread is a low-level implementation detail. Drivers should
  89. use the <linux/kthread.h> API instead which shields them from
  90. implementation details and provides a higherlevel interface that
  91. prevents bugs and code duplication
  92. Who: Christoph Hellwig <hch@lst.de>
  93. ---------------------------
  94. What: CONFIG_FORCED_INLINING
  95. When: June 2006
  96. Why: Config option is there to see if gcc is good enough. (in january
  97. 2006). If it is, the behavior should just be the default. If it's not,
  98. the option should just go away entirely.
  99. Who: Arjan van de Ven
  100. ---------------------------
  101. What: eepro100 network driver
  102. When: January 2007
  103. Why: replaced by the e100 driver
  104. Who: Adrian Bunk <bunk@stusta.de>
  105. ---------------------------
  106. What: drivers depending on OSS_OBSOLETE_DRIVER
  107. When: options in 2.6.20, code in 2.6.22
  108. Why: OSS drivers with ALSA replacements
  109. Who: Adrian Bunk <bunk@stusta.de>
  110. ---------------------------
  111. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  112. (temporary transition config option provided until then)
  113. The transition config option will also be removed at the same time.
  114. When: before 2.6.19
  115. Why: Unused symbols are both increasing the size of the kernel binary
  116. and are often a sign of "wrong API"
  117. Who: Arjan van de Ven <arjan@linux.intel.com>
  118. ---------------------------
  119. What: USB driver API moves to EXPORT_SYMBOL_GPL
  120. When: February 2008
  121. Files: include/linux/usb.h, drivers/usb/core/driver.c
  122. Why: The USB subsystem has changed a lot over time, and it has been
  123. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  124. that operate as fast as the USB bus allows. Because of this, the USB
  125. subsystem will not be allowing closed source kernel drivers to
  126. register with it, after this grace period is over. If anyone needs
  127. any help in converting their closed source drivers over to use the
  128. userspace filesystems, please contact the
  129. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  130. there will be glad to help you out.
  131. Who: Greg Kroah-Hartman <gregkh@suse.de>
  132. ---------------------------
  133. What: Interrupt only SA_* flags
  134. When: September 2007
  135. Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
  136. out of the signal namespace.
  137. Who: Thomas Gleixner <tglx@linutronix.de>
  138. ---------------------------
  139. What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
  140. When: October 2008
  141. Why: The stacking of class devices makes these values misleading and
  142. inconsistent.
  143. Class devices should not carry any of these properties, and bus
  144. devices have SUBSYTEM and DRIVER as a replacement.
  145. Who: Kay Sievers <kay.sievers@suse.de>
  146. ---------------------------
  147. What: i2c-isa
  148. When: December 2006
  149. Why: i2c-isa is a non-sense and doesn't fit in the device driver
  150. model. Drivers relying on it are better implemented as platform
  151. drivers.
  152. Who: Jean Delvare <khali@linux-fr.org>
  153. ---------------------------
  154. What: i2c_adapter.list
  155. When: July 2007
  156. Why: Superfluous, this list duplicates the one maintained by the driver
  157. core.
  158. Who: Jean Delvare <khali@linux-fr.org>,
  159. David Brownell <dbrownell@users.sourceforge.net>
  160. ---------------------------
  161. What: drivers depending on OBSOLETE_OSS
  162. When: options in 2.6.22, code in 2.6.24
  163. Why: OSS drivers with ALSA replacements
  164. Who: Adrian Bunk <bunk@stusta.de>
  165. ---------------------------
  166. What: ACPI hooks (X86_SPEEDSTEP_CENTRINO_ACPI) in speedstep-centrino driver
  167. When: December 2006
  168. Why: Speedstep-centrino driver with ACPI hooks and acpi-cpufreq driver are
  169. functionally very much similar. They talk to ACPI in same way. Only
  170. difference between them is the way they do frequency transitions.
  171. One uses MSRs and the other one uses IO ports. Functionaliy of
  172. speedstep_centrino with ACPI hooks is now merged into acpi-cpufreq.
  173. That means one common driver will support all Intel Enhanced Speedstep
  174. capable CPUs. That means less confusion over name of
  175. speedstep-centrino driver (with that driver supposed to be used on
  176. non-centrino platforms). That means less duplication of code and
  177. less maintenance effort and no possibility of these two drivers
  178. going out of sync.
  179. Current users of speedstep_centrino with ACPI hooks are requested to
  180. switch over to acpi-cpufreq driver. speedstep-centrino will continue
  181. to work using older non-ACPI static table based scheme even after this
  182. date.
  183. Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  184. ---------------------------
  185. What: /sys/firmware/acpi/namespace
  186. When: 2.6.21
  187. Why: The ACPI namespace is effectively the symbol list for
  188. the BIOS. The device names are completely arbitrary
  189. and have no place being exposed to user-space.
  190. For those interested in the BIOS ACPI namespace,
  191. the BIOS can be extracted and disassembled with acpidump
  192. and iasl as documented in the pmtools package here:
  193. http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
  194. Who: Len Brown <len.brown@intel.com>
  195. ---------------------------
  196. What: ACPI procfs interface
  197. When: July 2007
  198. Why: After ACPI sysfs conversion, ACPI attributes will be duplicated
  199. in sysfs and the ACPI procfs interface should be removed.
  200. Who: Zhang Rui <rui.zhang@intel.com>
  201. ---------------------------
  202. What: /proc/acpi/button
  203. When: August 2007
  204. Why: /proc/acpi/button has been replaced by events to the input layer
  205. since 2.6.20.
  206. Who: Len Brown <len.brown@intel.com>
  207. ---------------------------
  208. What: sk98lin network driver
  209. When: July 2007
  210. Why: In kernel tree version of driver is unmaintained. Sk98lin driver
  211. replaced by the skge driver.
  212. Who: Stephen Hemminger <shemminger@osdl.org>
  213. ---------------------------
  214. What: Compaq touchscreen device emulation
  215. When: Oct 2007
  216. Files: drivers/input/tsdev.c
  217. Why: The code says it was obsolete when it was written in 2001.
  218. tslib is a userspace library which does anything tsdev can do and
  219. much more besides in userspace where this code belongs. There is no
  220. longer any need for tsdev and applications should have converted to
  221. use tslib by now.
  222. The name "tsdev" is also extremely confusing and lots of people have
  223. it loaded when they don't need/use it.
  224. Who: Richard Purdie <rpurdie@rpsys.net>
  225. ---------------------------
  226. What: Multipath cached routing support in ipv4
  227. When: in 2.6.23
  228. Why: Code was merged, then submitter immediately disappeared leaving
  229. us with no maintainer and lots of bugs. The code should not have
  230. been merged in the first place, and many aspects of it's
  231. implementation are blocking more critical core networking
  232. development. It's marked EXPERIMENTAL and no distribution
  233. enables it because it cause obscure crashes due to unfixable bugs
  234. (interfaces don't return errors so memory allocation can't be
  235. handled, calling contexts of these interfaces make handling
  236. errors impossible too because they get called after we've
  237. totally commited to creating a route object, for example).
  238. This problem has existed for years and no forward progress
  239. has ever been made, and nobody steps up to try and salvage
  240. this code, so we're going to finally just get rid of it.
  241. Who: David S. Miller <davem@davemloft.net>
  242. ---------------------------
  243. What: read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
  244. When: December 2007
  245. Why: These functions are a leftover from 2.4 times. They have several
  246. problems:
  247. - Duplication of checks that are done in the device driver's
  248. interrupt handler
  249. - common I/O layer can't do device specific error recovery
  250. - device driver can't be notified for conditions happening during
  251. execution of the function
  252. Device drivers should issue the read device characteristics and read
  253. configuration data ccws and do the appropriate error handling
  254. themselves.
  255. Who: Cornelia Huck <cornelia.huck@de.ibm.com>
  256. ---------------------------
  257. What: i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
  258. When: September 2007
  259. Why: Obsolete. The new i2c-gpio driver replaces all hardware-specific
  260. I2C-over-GPIO drivers.
  261. Who: Jean Delvare <khali@linux-fr.org>
  262. ---------------------------
  263. What: drivers depending on OSS_OBSOLETE
  264. When: options in 2.6.23, code in 2.6.25
  265. Why: obsolete OSS drivers
  266. Who: Adrian Bunk <bunk@stusta.de>
  267. ---------------------------
  268. What: libata.spindown_compat module parameter
  269. When: Dec 2008
  270. Why: halt(8) synchronizes caches for and spins down libata disks
  271. because libata didn't use to spin down disk on system halt
  272. (only synchronized caches).
  273. Spin down on system halt is now implemented and can be tested
  274. using sysfs node /sys/class/scsi_disk/h:c:i:l/manage_start_stop.
  275. Because issuing spin down command to an already spun down disk
  276. makes some disks spin up just to spin down again, the old
  277. behavior needs to be maintained till userspace tool is updated
  278. to check the sysfs node and not to spin down disks with the
  279. node set to one.
  280. This module parameter is to give userspace tool the time to
  281. get updated and should be removed after userspace is
  282. reasonably updated.
  283. Who: Tejun Heo <htejun@gmail.com>
  284. ---------------------------