feature-removal-schedule.txt 10 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: /sys/devices/.../power/state
  8. dev->power.power_state
  9. dpm_runtime_{suspend,resume)()
  10. When: July 2007
  11. Why: Broken design for runtime control over driver power states, confusing
  12. driver-internal runtime power management with: mechanisms to support
  13. system-wide sleep state transitions; event codes that distinguish
  14. different phases of swsusp "sleep" transitions; and userspace policy
  15. inputs. This framework was never widely used, and most attempts to
  16. use it were broken. Drivers should instead be exposing domain-specific
  17. interfaces either to kernel or to userspace.
  18. Who: Pavel Machek <pavel@suse.cz>
  19. ---------------------------
  20. What: RAW driver (CONFIG_RAW_DRIVER)
  21. When: December 2005
  22. Why: declared obsolete since kernel 2.6.3
  23. O_DIRECT can be used instead
  24. Who: Adrian Bunk <bunk@stusta.de>
  25. ---------------------------
  26. What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  27. When: June 2007
  28. Why: Deprecated in favour of the more efficient and robust rawiso interface.
  29. Affected are applications which use the deprecated part of libraw1394
  30. (raw1394_iso_write, raw1394_start_iso_write, raw1394_start_iso_rcv,
  31. raw1394_stop_iso_rcv) or bypass libraw1394.
  32. Who: Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>
  33. ---------------------------
  34. What: dv1394 driver (CONFIG_IEEE1394_DV1394)
  35. When: June 2007
  36. Why: Replaced by raw1394 + userspace libraries, notably libiec61883. This
  37. shift of application support has been indicated on www.linux1394.org
  38. and developers' mailinglists for quite some time. Major applications
  39. have been converted, with the exception of ffmpeg and hence xine.
  40. Piped output of dvgrab2 is a partial equivalent to dv1394.
  41. Who: Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>
  42. ---------------------------
  43. What: ieee1394 core's unused exports (CONFIG_IEEE1394_EXPORT_FULL_API)
  44. When: January 2007
  45. Why: There are no projects known to use these exported symbols.
  46. Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
  47. ---------------------------
  48. What: ieee1394's *_oui sysfs attributes (CONFIG_IEEE1394_OUI_DB)
  49. When: January 2007
  50. Files: drivers/ieee1394/: oui.db, oui2c.sh
  51. Why: big size, little value
  52. Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
  53. ---------------------------
  54. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  55. When: December 2006
  56. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  57. series. The old API have lots of drawbacks and don't provide enough
  58. means to work with all video and audio standards. The newer API is
  59. already available on the main drivers and should be used instead.
  60. Newer drivers should use v4l_compat_translate_ioctl function to handle
  61. old calls, replacing to newer ones.
  62. Decoder iocts are using internally to allow video drivers to
  63. communicate with video decoders. This should also be improved to allow
  64. V4L2 calls being translated into compatible internal ioctls.
  65. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  66. ---------------------------
  67. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  68. When: November 2005
  69. Files: drivers/pcmcia/: pcmcia_ioctl.c
  70. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  71. normal hotpluggable bus, and with it using the default kernel
  72. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  73. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  74. unnecessary, and makes further cleanups and integration of the
  75. PCMCIA subsystem into the Linux kernel device driver model more
  76. difficult. The features provided by cardmgr and cardctl are either
  77. handled by the kernel itself now or are available in the new
  78. pcmciautils package available at
  79. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  80. Who: Dominik Brodowski <linux@brodo.de>
  81. ---------------------------
  82. What: remove EXPORT_SYMBOL(kernel_thread)
  83. When: August 2006
  84. Files: arch/*/kernel/*_ksyms.c
  85. Why: kernel_thread is a low-level implementation detail. Drivers should
  86. use the <linux/kthread.h> API instead which shields them from
  87. implementation details and provides a higherlevel interface that
  88. prevents bugs and code duplication
  89. Who: Christoph Hellwig <hch@lst.de>
  90. ---------------------------
  91. What: CONFIG_FORCED_INLINING
  92. When: June 2006
  93. Why: Config option is there to see if gcc is good enough. (in january
  94. 2006). If it is, the behavior should just be the default. If it's not,
  95. the option should just go away entirely.
  96. Who: Arjan van de Ven
  97. ---------------------------
  98. What: eepro100 network driver
  99. When: January 2007
  100. Why: replaced by the e100 driver
  101. Who: Adrian Bunk <bunk@stusta.de>
  102. ---------------------------
  103. What: drivers depending on OSS_OBSOLETE_DRIVER
  104. When: options in 2.6.20, code in 2.6.22
  105. Why: OSS drivers with ALSA replacements
  106. Who: Adrian Bunk <bunk@stusta.de>
  107. ---------------------------
  108. What: pci_module_init(driver)
  109. When: January 2007
  110. Why: Is replaced by pci_register_driver(pci_driver).
  111. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  112. ---------------------------
  113. What: Usage of invalid timevals in setitimer
  114. When: March 2007
  115. Why: POSIX requires to validate timevals in the setitimer call. This
  116. was never done by Linux. The invalid (e.g. negative timevals) were
  117. silently converted to more or less random timeouts and intervals.
  118. Until the removal a per boot limited number of warnings is printed
  119. and the timevals are sanitized.
  120. Who: Thomas Gleixner <tglx@linutronix.de>
  121. ---------------------------
  122. What: I2C interface of the it87 driver
  123. When: January 2007
  124. Why: The ISA interface is faster and should be always available. The I2C
  125. probing is also known to cause trouble in at least one case (see
  126. bug #5889.)
  127. Who: Jean Delvare <khali@linux-fr.org>
  128. ---------------------------
  129. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  130. (temporary transition config option provided until then)
  131. The transition config option will also be removed at the same time.
  132. When: before 2.6.19
  133. Why: Unused symbols are both increasing the size of the kernel binary
  134. and are often a sign of "wrong API"
  135. Who: Arjan van de Ven <arjan@linux.intel.com>
  136. ---------------------------
  137. What: mount/umount uevents
  138. When: February 2007
  139. Why: These events are not correct, and do not properly let userspace know
  140. when a file system has been mounted or unmounted. Userspace should
  141. poll the /proc/mounts file instead to detect this properly.
  142. Who: Greg Kroah-Hartman <gregkh@suse.de>
  143. ---------------------------
  144. What: USB driver API moves to EXPORT_SYMBOL_GPL
  145. When: February 2008
  146. Files: include/linux/usb.h, drivers/usb/core/driver.c
  147. Why: The USB subsystem has changed a lot over time, and it has been
  148. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  149. that operate as fast as the USB bus allows. Because of this, the USB
  150. subsystem will not be allowing closed source kernel drivers to
  151. register with it, after this grace period is over. If anyone needs
  152. any help in converting their closed source drivers over to use the
  153. userspace filesystems, please contact the
  154. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  155. there will be glad to help you out.
  156. Who: Greg Kroah-Hartman <gregkh@suse.de>
  157. ---------------------------
  158. What: find_trylock_page
  159. When: January 2007
  160. Why: The interface no longer has any callers left in the kernel. It
  161. is an odd interface (compared with other find_*_page functions), in
  162. that it does not take a refcount to the page, only the page lock.
  163. It should be replaced with find_get_page or find_lock_page if possible.
  164. This feature removal can be reevaluated if users of the interface
  165. cannot cleanly use something else.
  166. Who: Nick Piggin <npiggin@suse.de>
  167. ---------------------------
  168. What: Interrupt only SA_* flags
  169. When: Januar 2007
  170. Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
  171. out of the signal namespace.
  172. Who: Thomas Gleixner <tglx@linutronix.de>
  173. ---------------------------
  174. What: i2c-ite and i2c-algo-ite drivers
  175. When: September 2006
  176. Why: These drivers never compiled since they were added to the kernel
  177. tree 5 years ago. This feature removal can be reevaluated if
  178. someone shows interest in the drivers, fixes them and takes over
  179. maintenance.
  180. http://marc.theaimsgroup.com/?l=linux-mips&m=115040510817448
  181. Who: Jean Delvare <khali@linux-fr.org>
  182. ---------------------------
  183. What: Bridge netfilter deferred IPv4/IPv6 output hook calling
  184. When: January 2007
  185. Why: The deferred output hooks are a layering violation causing unusual
  186. and broken behaviour on bridge devices. Examples of things they
  187. break include QoS classifation using the MARK or CLASSIFY targets,
  188. the IPsec policy match and connection tracking with VLANs on a
  189. bridge. Their only use is to enable bridge output port filtering
  190. within iptables with the physdev match, which can also be done by
  191. combining iptables and ebtables using netfilter marks. Until it
  192. will get removed the hook deferral is disabled by default and is
  193. only enabled when needed.
  194. Who: Patrick McHardy <kaber@trash.net>
  195. ---------------------------
  196. What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
  197. When: October 2008
  198. Why: The stacking of class devices makes these values misleading and
  199. inconsistent.
  200. Class devices should not carry any of these properties, and bus
  201. devices have SUBSYTEM and DRIVER as a replacement.
  202. Who: Kay Sievers <kay.sievers@suse.de>
  203. ---------------------------
  204. What: i2c-isa
  205. When: December 2006
  206. Why: i2c-isa is a non-sense and doesn't fit in the device driver
  207. model. Drivers relying on it are better implemented as platform
  208. drivers.
  209. Who: Jean Delvare <khali@linux-fr.org>
  210. ---------------------------
  211. What: IPv4 only connection tracking/NAT/helpers
  212. When: 2.6.22
  213. Why: The new layer 3 independant connection tracking replaces the old
  214. IPv4 only version. After some stabilization of the new code the
  215. old one will be removed.
  216. Who: Patrick McHardy <kaber@trash.net>
  217. ---------------------------