feature-removal-schedule.txt 8.3 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: devfs
  8. When: July 2005
  9. Files: fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
  10. function calls throughout the kernel tree
  11. Why: It has been unmaintained for a number of years, has unfixable
  12. races, contains a naming policy within the kernel that is
  13. against the LSB, and can be replaced by using udev.
  14. Who: Greg Kroah-Hartman <greg@kroah.com>
  15. ---------------------------
  16. What: RAW driver (CONFIG_RAW_DRIVER)
  17. When: December 2005
  18. Why: declared obsolete since kernel 2.6.3
  19. O_DIRECT can be used instead
  20. Who: Adrian Bunk <bunk@stusta.de>
  21. ---------------------------
  22. What: drivers that were depending on OBSOLETE_OSS_DRIVER
  23. (config options already removed)
  24. When: before 2.6.19
  25. Why: OSS drivers with ALSA replacements
  26. Who: Adrian Bunk <bunk@stusta.de>
  27. ---------------------------
  28. What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  29. When: November 2006
  30. Why: Deprecated in favour of the new ioctl-based rawiso interface, which is
  31. more efficient. You should really be using libraw1394 for raw1394
  32. access anyway.
  33. Who: Jody McIntyre <scjody@modernduck.com>
  34. ---------------------------
  35. What: sbp2: module parameter "force_inquiry_hack"
  36. When: July 2006
  37. Why: Superceded by parameter "workarounds". Both parameters are meant to be
  38. used ad-hoc and for single devices only, i.e. not in modprobe.conf,
  39. therefore the impact of this feature replacement should be low.
  40. Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
  41. ---------------------------
  42. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  43. When: July 2006
  44. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  45. series. The old API have lots of drawbacks and don't provide enough
  46. means to work with all video and audio standards. The newer API is
  47. already available on the main drivers and should be used instead.
  48. Newer drivers should use v4l_compat_translate_ioctl function to handle
  49. old calls, replacing to newer ones.
  50. Decoder iocts are using internally to allow video drivers to
  51. communicate with video decoders. This should also be improved to allow
  52. V4L2 calls being translated into compatible internal ioctls.
  53. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  54. ---------------------------
  55. What: remove EXPORT_SYMBOL(insert_resource)
  56. When: April 2006
  57. Files: kernel/resource.c
  58. Why: No modular usage in the kernel.
  59. Who: Adrian Bunk <bunk@stusta.de>
  60. ---------------------------
  61. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  62. When: November 2005
  63. Files: drivers/pcmcia/: pcmcia_ioctl.c
  64. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  65. normal hotpluggable bus, and with it using the default kernel
  66. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  67. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  68. unnecessary, and makes further cleanups and integration of the
  69. PCMCIA subsystem into the Linux kernel device driver model more
  70. difficult. The features provided by cardmgr and cardctl are either
  71. handled by the kernel itself now or are available in the new
  72. pcmciautils package available at
  73. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  74. Who: Dominik Brodowski <linux@brodo.de>
  75. ---------------------------
  76. What: ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
  77. When: December 2005
  78. Why: This interface has been obsoleted by the new layer3-independent
  79. "nfnetlink_queue". The Kernel interface is compatible, so the old
  80. ip[6]tables "QUEUE" targets still work and will transparently handle
  81. all packets into nfnetlink queue number 0. Userspace users will have
  82. to link against API-compatible library on top of libnfnetlink_queue
  83. instead of the current 'libipq'.
  84. Who: Harald Welte <laforge@netfilter.org>
  85. ---------------------------
  86. What: remove EXPORT_SYMBOL(kernel_thread)
  87. When: August 2006
  88. Files: arch/*/kernel/*_ksyms.c
  89. Why: kernel_thread is a low-level implementation detail. Drivers should
  90. use the <linux/kthread.h> API instead which shields them from
  91. implementation details and provides a higherlevel interface that
  92. prevents bugs and code duplication
  93. Who: Christoph Hellwig <hch@lst.de>
  94. ---------------------------
  95. What: CONFIG_FORCED_INLINING
  96. When: June 2006
  97. Why: Config option is there to see if gcc is good enough. (in january
  98. 2006). If it is, the behavior should just be the default. If it's not,
  99. the option should just go away entirely.
  100. Who: Arjan van de Ven
  101. ---------------------------
  102. What: START_ARRAY ioctl for md
  103. When: July 2006
  104. Files: drivers/md/md.c
  105. Why: Not reliable by design - can fail when most needed.
  106. Alternatives exist
  107. Who: NeilBrown <neilb@suse.de>
  108. ---------------------------
  109. What: eepro100 network driver
  110. When: January 2007
  111. Why: replaced by the e100 driver
  112. Who: Adrian Bunk <bunk@stusta.de>
  113. ---------------------------
  114. What: pci_module_init(driver)
  115. When: January 2007
  116. Why: Is replaced by pci_register_driver(pci_driver).
  117. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  118. ---------------------------
  119. What: Usage of invalid timevals in setitimer
  120. When: March 2007
  121. Why: POSIX requires to validate timevals in the setitimer call. This
  122. was never done by Linux. The invalid (e.g. negative timevals) were
  123. silently converted to more or less random timeouts and intervals.
  124. Until the removal a per boot limited number of warnings is printed
  125. and the timevals are sanitized.
  126. Who: Thomas Gleixner <tglx@linutronix.de>
  127. ---------------------------
  128. What: I2C interface of the it87 driver
  129. When: January 2007
  130. Why: The ISA interface is faster and should be always available. The I2C
  131. probing is also known to cause trouble in at least one case (see
  132. bug #5889.)
  133. Who: Jean Delvare <khali@linux-fr.org>
  134. ---------------------------
  135. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  136. (temporary transition config option provided until then)
  137. The transition config option will also be removed at the same time.
  138. When: before 2.6.19
  139. Why: Unused symbols are both increasing the size of the kernel binary
  140. and are often a sign of "wrong API"
  141. Who: Arjan van de Ven <arjan@linux.intel.com>
  142. ---------------------------
  143. What: remove EXPORT_SYMBOL(tasklist_lock)
  144. When: August 2006
  145. Files: kernel/fork.c
  146. Why: tasklist_lock protects the kernel internal task list. Modules have
  147. no business looking at it, and all instances in drivers have been due
  148. to use of too-lowlevel APIs. Having this symbol exported prevents
  149. moving to more scalable locking schemes for the task list.
  150. Who: Christoph Hellwig <hch@lst.de>
  151. ---------------------------
  152. What: mount/umount uevents
  153. When: February 2007
  154. Why: These events are not correct, and do not properly let userspace know
  155. when a file system has been mounted or unmounted. Userspace should
  156. poll the /proc/mounts file instead to detect this properly.
  157. Who: Greg Kroah-Hartman <gregkh@suse.de>
  158. ---------------------------
  159. What: USB driver API moves to EXPORT_SYMBOL_GPL
  160. When: Febuary 2008
  161. Files: include/linux/usb.h, drivers/usb/core/driver.c
  162. Why: The USB subsystem has changed a lot over time, and it has been
  163. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  164. that operate as fast as the USB bus allows. Because of this, the USB
  165. subsystem will not be allowing closed source kernel drivers to
  166. register with it, after this grace period is over. If anyone needs
  167. any help in converting their closed source drivers over to use the
  168. userspace filesystems, please contact the
  169. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  170. there will be glad to help you out.
  171. Who: Greg Kroah-Hartman <gregkh@suse.de>
  172. ---------------------------
  173. What: find_trylock_page
  174. When: January 2007
  175. Why: The interface no longer has any callers left in the kernel. It
  176. is an odd interface (compared with other find_*_page functions), in
  177. that it does not take a refcount to the page, only the page lock.
  178. It should be replaced with find_get_page or find_lock_page if possible.
  179. This feature removal can be reevaluated if users of the interface
  180. cannot cleanly use something else.
  181. Who: Nick Piggin <npiggin@suse.de>
  182. ---------------------------