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 be 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. Files: include/linux/video_decoder.h
  60. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  61. series. The old API have lots of drawbacks and don't provide enough
  62. means to work with all video and audio standards. The newer API is
  63. already available on the main drivers and should be used instead.
  64. Newer drivers should use v4l_compat_translate_ioctl function to handle
  65. old calls, replacing to newer ones.
  66. Decoder iocts are using internally to allow video drivers to
  67. communicate with video decoders. This should also be improved to allow
  68. V4L2 calls being translated into compatible internal ioctls.
  69. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  70. ---------------------------
  71. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  72. When: November 2005
  73. Files: drivers/pcmcia/: pcmcia_ioctl.c
  74. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  75. normal hotpluggable bus, and with it using the default kernel
  76. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  77. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  78. unnecessary, and makes further cleanups and integration of the
  79. PCMCIA subsystem into the Linux kernel device driver model more
  80. difficult. The features provided by cardmgr and cardctl are either
  81. handled by the kernel itself now or are available in the new
  82. pcmciautils package available at
  83. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  84. Who: Dominik Brodowski <linux@brodo.de>
  85. ---------------------------
  86. What: remove EXPORT_SYMBOL(kernel_thread)
  87. When: August 2006
  88. Files: arch/*/kernel/*_ksyms.c
  89. Funcs: kernel_thread
  90. Why: kernel_thread is a low-level implementation detail. Drivers should
  91. use the <linux/kthread.h> API instead which shields them from
  92. implementation details and provides a higherlevel interface that
  93. prevents bugs and code duplication
  94. Who: Christoph Hellwig <hch@lst.de>
  95. ---------------------------
  96. What: CONFIG_FORCED_INLINING
  97. When: June 2006
  98. Why: Config option is there to see if gcc is good enough. (in january
  99. 2006). If it is, the behavior should just be the default. If it's not,
  100. the option should just go away entirely.
  101. Who: Arjan van de Ven
  102. ---------------------------
  103. What: eepro100 network driver
  104. When: January 2007
  105. Why: replaced by the e100 driver
  106. Who: Adrian Bunk <bunk@stusta.de>
  107. ---------------------------
  108. What: drivers depending on OSS_OBSOLETE_DRIVER
  109. When: options in 2.6.20, code in 2.6.22
  110. Why: OSS drivers with ALSA replacements
  111. Who: Adrian Bunk <bunk@stusta.de>
  112. ---------------------------
  113. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  114. (temporary transition config option provided until then)
  115. The transition config option will also be removed at the same time.
  116. When: before 2.6.19
  117. Why: Unused symbols are both increasing the size of the kernel binary
  118. and are often a sign of "wrong API"
  119. Who: Arjan van de Ven <arjan@linux.intel.com>
  120. ---------------------------
  121. What: USB driver API moves to EXPORT_SYMBOL_GPL
  122. When: February 2008
  123. Files: include/linux/usb.h, drivers/usb/core/driver.c
  124. Why: The USB subsystem has changed a lot over time, and it has been
  125. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  126. that operate as fast as the USB bus allows. Because of this, the USB
  127. subsystem will not be allowing closed source kernel drivers to
  128. register with it, after this grace period is over. If anyone needs
  129. any help in converting their closed source drivers over to use the
  130. userspace filesystems, please contact the
  131. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  132. there will be glad to help you out.
  133. Who: Greg Kroah-Hartman <gregkh@suse.de>
  134. ---------------------------
  135. What: Interrupt only SA_* flags
  136. When: September 2007
  137. Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
  138. out of the signal namespace.
  139. Who: Thomas Gleixner <tglx@linutronix.de>
  140. ---------------------------
  141. What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
  142. When: October 2008
  143. Why: The stacking of class devices makes these values misleading and
  144. inconsistent.
  145. Class devices should not carry any of these properties, and bus
  146. devices have SUBSYTEM and DRIVER as a replacement.
  147. Who: Kay Sievers <kay.sievers@suse.de>
  148. ---------------------------
  149. What: i2c-isa
  150. When: December 2006
  151. Why: i2c-isa is a non-sense and doesn't fit in the device driver
  152. model. Drivers relying on it are better implemented as platform
  153. drivers.
  154. Who: Jean Delvare <khali@linux-fr.org>
  155. ---------------------------
  156. What: i2c_adapter.list
  157. When: July 2007
  158. Why: Superfluous, this list duplicates the one maintained by the driver
  159. core.
  160. Who: Jean Delvare <khali@linux-fr.org>,
  161. David Brownell <dbrownell@users.sourceforge.net>
  162. ---------------------------
  163. What: drivers depending on OBSOLETE_OSS
  164. When: options in 2.6.22, code in 2.6.24
  165. Why: OSS drivers with ALSA replacements
  166. Who: Adrian Bunk <bunk@stusta.de>
  167. ---------------------------
  168. What: ACPI hooks (X86_SPEEDSTEP_CENTRINO_ACPI) in speedstep-centrino driver
  169. When: December 2006
  170. Why: Speedstep-centrino driver with ACPI hooks and acpi-cpufreq driver are
  171. functionally very much similar. They talk to ACPI in same way. Only
  172. difference between them is the way they do frequency transitions.
  173. One uses MSRs and the other one uses IO ports. Functionaliy of
  174. speedstep_centrino with ACPI hooks is now merged into acpi-cpufreq.
  175. That means one common driver will support all Intel Enhanced Speedstep
  176. capable CPUs. That means less confusion over name of
  177. speedstep-centrino driver (with that driver supposed to be used on
  178. non-centrino platforms). That means less duplication of code and
  179. less maintenance effort and no possibility of these two drivers
  180. going out of sync.
  181. Current users of speedstep_centrino with ACPI hooks are requested to
  182. switch over to acpi-cpufreq driver. speedstep-centrino will continue
  183. to work using older non-ACPI static table based scheme even after this
  184. date.
  185. Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  186. ---------------------------
  187. What: /sys/firmware/acpi/namespace
  188. When: 2.6.21
  189. Why: The ACPI namespace is effectively the symbol list for
  190. the BIOS. The device names are completely arbitrary
  191. and have no place being exposed to user-space.
  192. For those interested in the BIOS ACPI namespace,
  193. the BIOS can be extracted and disassembled with acpidump
  194. and iasl as documented in the pmtools package here:
  195. http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
  196. Who: Len Brown <len.brown@intel.com>
  197. ---------------------------
  198. What: ACPI procfs interface
  199. When: July 2007
  200. Why: After ACPI sysfs conversion, ACPI attributes will be duplicated
  201. in sysfs and the ACPI procfs interface should be removed.
  202. Who: Zhang Rui <rui.zhang@intel.com>
  203. ---------------------------
  204. What: /proc/acpi/button
  205. When: August 2007
  206. Why: /proc/acpi/button has been replaced by events to the input layer
  207. since 2.6.20.
  208. Who: Len Brown <len.brown@intel.com>
  209. ---------------------------
  210. What: sk98lin network driver
  211. When: July 2007
  212. Why: In kernel tree version of driver is unmaintained. Sk98lin driver
  213. replaced by the skge driver.
  214. Who: Stephen Hemminger <shemminger@osdl.org>
  215. ---------------------------
  216. What: Compaq touchscreen device emulation
  217. When: Oct 2007
  218. Files: drivers/input/tsdev.c
  219. Why: The code says it was obsolete when it was written in 2001.
  220. tslib is a userspace library which does anything tsdev can do and
  221. much more besides in userspace where this code belongs. There is no
  222. longer any need for tsdev and applications should have converted to
  223. use tslib by now.
  224. The name "tsdev" is also extremely confusing and lots of people have
  225. it loaded when they don't need/use it.
  226. Who: Richard Purdie <rpurdie@rpsys.net>
  227. ---------------------------
  228. What: Multipath cached routing support in ipv4
  229. When: in 2.6.23
  230. Why: Code was merged, then submitter immediately disappeared leaving
  231. us with no maintainer and lots of bugs. The code should not have
  232. been merged in the first place, and many aspects of it's
  233. implementation are blocking more critical core networking
  234. development. It's marked EXPERIMENTAL and no distribution
  235. enables it because it cause obscure crashes due to unfixable bugs
  236. (interfaces don't return errors so memory allocation can't be
  237. handled, calling contexts of these interfaces make handling
  238. errors impossible too because they get called after we've
  239. totally commited to creating a route object, for example).
  240. This problem has existed for years and no forward progress
  241. has ever been made, and nobody steps up to try and salvage
  242. this code, so we're going to finally just get rid of it.
  243. Who: David S. Miller <davem@davemloft.net>
  244. ---------------------------
  245. What: read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
  246. When: December 2007
  247. Why: These functions are a leftover from 2.4 times. They have several
  248. problems:
  249. - Duplication of checks that are done in the device driver's
  250. interrupt handler
  251. - common I/O layer can't do device specific error recovery
  252. - device driver can't be notified for conditions happening during
  253. execution of the function
  254. Device drivers should issue the read device characteristics and read
  255. configuration data ccws and do the appropriate error handling
  256. themselves.
  257. Who: Cornelia Huck <cornelia.huck@de.ibm.com>
  258. ---------------------------
  259. What: i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
  260. When: September 2007
  261. Why: Obsolete. The new i2c-gpio driver replaces all hardware-specific
  262. I2C-over-GPIO drivers.
  263. Who: Jean Delvare <khali@linux-fr.org>
  264. ---------------------------
  265. What: drivers depending on OSS_OBSOLETE
  266. When: options in 2.6.23, code in 2.6.25
  267. Why: obsolete OSS drivers
  268. Who: Adrian Bunk <bunk@stusta.de>
  269. ---------------------------
  270. What: libata spindown skipping and warning
  271. When: Dec 2008
  272. Why: Some halt(8) implementations synchronize caches for and spin
  273. down libata disks because libata didn't use to spin down disk on
  274. system halt (only synchronized caches).
  275. Spin down on system halt is now implemented. sysfs node
  276. /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
  277. spin down support is available.
  278. Because issuing spin down command to an already spun down disk
  279. makes some disks spin up just to spin down again, libata tracks
  280. device spindown status to skip the extra spindown command and
  281. warn about it.
  282. This is to give userspace tools the time to get updated and will
  283. be removed after userspace is reasonably updated.
  284. Who: Tejun Heo <htejun@gmail.com>
  285. ---------------------------