feature-removal-schedule.txt 12 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: dev->power.power_state
  24. When: July 2007
  25. Why: Broken design for runtime control over driver power states, confusing
  26. driver-internal runtime power management with: mechanisms to support
  27. system-wide sleep state transitions; event codes that distinguish
  28. different phases of swsusp "sleep" transitions; and userspace policy
  29. inputs. This framework was never widely used, and most attempts to
  30. use it were broken. Drivers should instead be exposing domain-specific
  31. interfaces either to kernel or to userspace.
  32. Who: Pavel Machek <pavel@suse.cz>
  33. ---------------------------
  34. What: old NCR53C9x driver
  35. When: October 2007
  36. Why: Replaced by the much better esp_scsi driver. Actual low-level
  37. driver can be ported over almost trivially.
  38. Who: David Miller <davem@davemloft.net>
  39. Christoph Hellwig <hch@lst.de>
  40. ---------------------------
  41. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  42. When: December 2006
  43. Files: include/linux/video_decoder.h
  44. Check: include/linux/video_decoder.h
  45. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  46. series. The old API have lots of drawbacks and don't provide enough
  47. means to work with all video and audio standards. The newer API is
  48. already available on the main drivers and should be used instead.
  49. Newer drivers should use v4l_compat_translate_ioctl function to handle
  50. old calls, replacing to newer ones.
  51. Decoder iocts are using internally to allow video drivers to
  52. communicate with video decoders. This should also be improved to allow
  53. V4L2 calls being translated into compatible internal ioctls.
  54. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  55. ---------------------------
  56. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  57. When: November 2005
  58. Files: drivers/pcmcia/: pcmcia_ioctl.c
  59. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  60. normal hotpluggable bus, and with it using the default kernel
  61. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  62. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  63. unnecessary, and makes further cleanups and integration of the
  64. PCMCIA subsystem into the Linux kernel device driver model more
  65. difficult. The features provided by cardmgr and cardctl are either
  66. handled by the kernel itself now or are available in the new
  67. pcmciautils package available at
  68. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  69. Who: Dominik Brodowski <linux@brodo.de>
  70. ---------------------------
  71. What: a.out interpreter support for ELF executables
  72. When: 2.6.25
  73. Files: fs/binfmt_elf.c
  74. Why: Using a.out interpreters for ELF executables was a feature for
  75. transition from a.out to ELF. But now it is unlikely to be still
  76. needed anymore and removing it would simplify the hairy ELF
  77. loader code.
  78. Who: Andi Kleen <ak@suse.de>
  79. ---------------------------
  80. What: remove EXPORT_SYMBOL(kernel_thread)
  81. When: August 2006
  82. Files: arch/*/kernel/*_ksyms.c
  83. Check: kernel_thread
  84. Why: kernel_thread is a low-level implementation detail. Drivers should
  85. use the <linux/kthread.h> API instead which shields them from
  86. implementation details and provides a higherlevel interface that
  87. prevents bugs and code duplication
  88. Who: Christoph Hellwig <hch@lst.de>
  89. ---------------------------
  90. What: CONFIG_FORCED_INLINING
  91. When: June 2006
  92. Why: Config option is there to see if gcc is good enough. (in january
  93. 2006). If it is, the behavior should just be the default. If it's not,
  94. the option should just go away entirely.
  95. Who: Arjan van de Ven
  96. ---------------------------
  97. What: eepro100 network driver
  98. When: January 2007
  99. Why: replaced by the e100 driver
  100. Who: Adrian Bunk <bunk@stusta.de>
  101. ---------------------------
  102. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  103. (temporary transition config option provided until then)
  104. The transition config option will also be removed at the same time.
  105. When: before 2.6.19
  106. Why: Unused symbols are both increasing the size of the kernel binary
  107. and are often a sign of "wrong API"
  108. Who: Arjan van de Ven <arjan@linux.intel.com>
  109. ---------------------------
  110. What: USB driver API moves to EXPORT_SYMBOL_GPL
  111. When: February 2008
  112. Files: include/linux/usb.h, drivers/usb/core/driver.c
  113. Why: The USB subsystem has changed a lot over time, and it has been
  114. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  115. that operate as fast as the USB bus allows. Because of this, the USB
  116. subsystem will not be allowing closed source kernel drivers to
  117. register with it, after this grace period is over. If anyone needs
  118. any help in converting their closed source drivers over to use the
  119. userspace filesystems, please contact the
  120. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  121. there will be glad to help you out.
  122. Who: Greg Kroah-Hartman <gregkh@suse.de>
  123. ---------------------------
  124. What: vm_ops.nopage
  125. When: Soon, provided in-kernel callers have been converted
  126. Why: This interface is replaced by vm_ops.fault, but it has been around
  127. forever, is used by a lot of drivers, and doesn't cost much to
  128. maintain.
  129. Who: Nick Piggin <npiggin@suse.de>
  130. ---------------------------
  131. What: Interrupt only SA_* flags
  132. When: September 2007
  133. Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
  134. out of the signal namespace.
  135. Who: Thomas Gleixner <tglx@linutronix.de>
  136. ---------------------------
  137. What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
  138. When: October 2008
  139. Why: The stacking of class devices makes these values misleading and
  140. inconsistent.
  141. Class devices should not carry any of these properties, and bus
  142. devices have SUBSYTEM and DRIVER as a replacement.
  143. Who: Kay Sievers <kay.sievers@suse.de>
  144. ---------------------------
  145. What: i2c_adapter.list
  146. When: July 2007
  147. Why: Superfluous, this list duplicates the one maintained by the driver
  148. core.
  149. Who: Jean Delvare <khali@linux-fr.org>,
  150. David Brownell <dbrownell@users.sourceforge.net>
  151. ---------------------------
  152. What: drivers depending on OBSOLETE_OSS
  153. When: options in 2.6.22, code in 2.6.24
  154. Why: OSS drivers with ALSA replacements
  155. Who: Adrian Bunk <bunk@stusta.de>
  156. ---------------------------
  157. What: ACPI procfs interface
  158. When: July 2008
  159. Why: ACPI sysfs conversion should be finished by January 2008.
  160. ACPI procfs interface will be removed in July 2008 so that
  161. there is enough time for the user space to catch up.
  162. Who: Zhang Rui <rui.zhang@intel.com>
  163. ---------------------------
  164. What: /proc/acpi/button
  165. When: August 2007
  166. Why: /proc/acpi/button has been replaced by events to the input layer
  167. since 2.6.20.
  168. Who: Len Brown <len.brown@intel.com>
  169. ---------------------------
  170. What: /proc/acpi/event
  171. When: February 2008
  172. Why: /proc/acpi/event has been replaced by events via the input layer
  173. and netlink since 2.6.23.
  174. Who: Len Brown <len.brown@intel.com>
  175. ---------------------------
  176. What: i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
  177. When: September 2007
  178. Why: Obsolete. The new i2c-gpio driver replaces all hardware-specific
  179. I2C-over-GPIO drivers.
  180. Who: Jean Delvare <khali@linux-fr.org>
  181. ---------------------------
  182. What: 'time' kernel boot parameter
  183. When: January 2008
  184. Why: replaced by 'printk.time=<value>' so that printk timestamps can be
  185. enabled or disabled as needed
  186. Who: Randy Dunlap <randy.dunlap@oracle.com>
  187. ---------------------------
  188. What: drivers depending on OSS_OBSOLETE
  189. When: options in 2.6.23, code in 2.6.25
  190. Why: obsolete OSS drivers
  191. Who: Adrian Bunk <bunk@stusta.de>
  192. ---------------------------
  193. What: libata spindown skipping and warning
  194. When: Dec 2008
  195. Why: Some halt(8) implementations synchronize caches for and spin
  196. down libata disks because libata didn't use to spin down disk on
  197. system halt (only synchronized caches).
  198. Spin down on system halt is now implemented. sysfs node
  199. /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
  200. spin down support is available.
  201. Because issuing spin down command to an already spun down disk
  202. makes some disks spin up just to spin down again, libata tracks
  203. device spindown status to skip the extra spindown command and
  204. warn about it.
  205. This is to give userspace tools the time to get updated and will
  206. be removed after userspace is reasonably updated.
  207. Who: Tejun Heo <htejun@gmail.com>
  208. ---------------------------
  209. What: Legacy RTC drivers (under drivers/i2c/chips)
  210. When: November 2007
  211. Why: Obsolete. We have a RTC subsystem with better drivers.
  212. Who: Jean Delvare <khali@linux-fr.org>
  213. ---------------------------
  214. What: iptables SAME target
  215. When: 1.1. 2008
  216. Files: net/ipv4/netfilter/ipt_SAME.c, include/linux/netfilter_ipv4/ipt_SAME.h
  217. Why: Obsolete for multiple years now, NAT core provides the same behaviour.
  218. Unfixable broken wrt. 32/64 bit cleanness.
  219. Who: Patrick McHardy <kaber@trash.net>
  220. ---------------------------
  221. What: The arch/ppc and include/asm-ppc directories
  222. When: Jun 2008
  223. Why: The arch/powerpc tree is the merged architecture for ppc32 and ppc64
  224. platforms. Currently there are efforts underway to port the remaining
  225. arch/ppc platforms to the merged tree. New submissions to the arch/ppc
  226. tree have been frozen with the 2.6.22 kernel release and that tree will
  227. remain in bug-fix only mode until its scheduled removal. Platforms
  228. that are not ported by June 2008 will be removed due to the lack of an
  229. interested maintainer.
  230. Who: linuxppc-dev@ozlabs.org
  231. ---------------------------
  232. What: mthca driver's MSI support
  233. When: January 2008
  234. Files: drivers/infiniband/hw/mthca/*.[ch]
  235. Why: All mthca hardware also supports MSI-X, which provides
  236. strictly more functionality than MSI. So there is no point in
  237. having both MSI-X and MSI support in the driver.
  238. Who: Roland Dreier <rolandd@cisco.com>
  239. ---------------------------
  240. What: sk98lin network driver
  241. When: Feburary 2008
  242. Why: In kernel tree version of driver is unmaintained. Sk98lin driver
  243. replaced by the skge driver.
  244. Who: Stephen Hemminger <shemminger@linux-foundation.org>
  245. ---------------------------
  246. What: i386/x86_64 bzImage symlinks
  247. When: April 2008
  248. Why: The i386/x86_64 merge provides a symlink to the old bzImage
  249. location so not yet updated user space tools, e.g. package
  250. scripts, do not break.
  251. Who: Thomas Gleixner <tglx@linutronix.de>
  252. ---------------------------
  253. What: shaper network driver
  254. When: January 2008
  255. Files: drivers/net/shaper.c, include/linux/if_shaper.h
  256. Why: This driver has been marked obsolete for many years.
  257. It was only designed to work on lower speed links and has design
  258. flaws that lead to machine crashes. The qdisc infrastructure in
  259. 2.4 or later kernels, provides richer features and is more robust.
  260. Who: Stephen Hemminger <shemminger@linux-foundation.org>
  261. ---------------------------