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, except
  46. dfg1394 (uses one symbol whose functionality is core-internal now).
  47. Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
  48. ---------------------------
  49. What: ieee1394's *_oui sysfs attributes (CONFIG_IEEE1394_OUI_DB)
  50. When: January 2007
  51. Files: drivers/ieee1394/: oui.db, oui2c.sh
  52. Why: big size, little value
  53. Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
  54. ---------------------------
  55. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  56. When: December 2006
  57. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  58. series. The old API have lots of drawbacks and don't provide enough
  59. means to work with all video and audio standards. The newer API is
  60. already available on the main drivers and should be used instead.
  61. Newer drivers should use v4l_compat_translate_ioctl function to handle
  62. old calls, replacing to newer ones.
  63. Decoder iocts are using internally to allow video drivers to
  64. communicate with video decoders. This should also be improved to allow
  65. V4L2 calls being translated into compatible internal ioctls.
  66. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  67. ---------------------------
  68. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  69. When: November 2005
  70. Files: drivers/pcmcia/: pcmcia_ioctl.c
  71. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  72. normal hotpluggable bus, and with it using the default kernel
  73. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  74. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  75. unnecessary, and makes further cleanups and integration of the
  76. PCMCIA subsystem into the Linux kernel device driver model more
  77. difficult. The features provided by cardmgr and cardctl are either
  78. handled by the kernel itself now or are available in the new
  79. pcmciautils package available at
  80. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  81. Who: Dominik Brodowski <linux@brodo.de>
  82. ---------------------------
  83. What: remove EXPORT_SYMBOL(kernel_thread)
  84. When: August 2006
  85. Files: arch/*/kernel/*_ksyms.c
  86. Why: kernel_thread is a low-level implementation detail. Drivers should
  87. use the <linux/kthread.h> API instead which shields them from
  88. implementation details and provides a higherlevel interface that
  89. prevents bugs and code duplication
  90. Who: Christoph Hellwig <hch@lst.de>
  91. ---------------------------
  92. What: CONFIG_FORCED_INLINING
  93. When: June 2006
  94. Why: Config option is there to see if gcc is good enough. (in january
  95. 2006). If it is, the behavior should just be the default. If it's not,
  96. the option should just go away entirely.
  97. Who: Arjan van de Ven
  98. ---------------------------
  99. What: eepro100 network driver
  100. When: January 2007
  101. Why: replaced by the e100 driver
  102. Who: Adrian Bunk <bunk@stusta.de>
  103. ---------------------------
  104. What: drivers depending on OSS_OBSOLETE_DRIVER
  105. When: options in 2.6.20, code in 2.6.22
  106. Why: OSS drivers with ALSA replacements
  107. Who: Adrian Bunk <bunk@stusta.de>
  108. ---------------------------
  109. What: pci_module_init(driver)
  110. When: January 2007
  111. Why: Is replaced by pci_register_driver(pci_driver).
  112. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  113. ---------------------------
  114. What: Usage of invalid timevals in setitimer
  115. When: March 2007
  116. Why: POSIX requires to validate timevals in the setitimer call. This
  117. was never done by Linux. The invalid (e.g. negative timevals) were
  118. silently converted to more or less random timeouts and intervals.
  119. Until the removal a per boot limited number of warnings is printed
  120. and the timevals are sanitized.
  121. Who: Thomas Gleixner <tglx@linutronix.de>
  122. ---------------------------
  123. What: I2C interface of the it87 driver
  124. When: January 2007
  125. Why: The ISA interface is faster and should be always available. The I2C
  126. probing is also known to cause trouble in at least one case (see
  127. bug #5889.)
  128. Who: Jean Delvare <khali@linux-fr.org>
  129. ---------------------------
  130. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  131. (temporary transition config option provided until then)
  132. The transition config option will also be removed at the same time.
  133. When: before 2.6.19
  134. Why: Unused symbols are both increasing the size of the kernel binary
  135. and are often a sign of "wrong API"
  136. Who: Arjan van de Ven <arjan@linux.intel.com>
  137. ---------------------------
  138. What: mount/umount uevents
  139. When: February 2007
  140. Why: These events are not correct, and do not properly let userspace know
  141. when a file system has been mounted or unmounted. Userspace should
  142. poll the /proc/mounts file instead to detect this properly.
  143. Who: Greg Kroah-Hartman <gregkh@suse.de>
  144. ---------------------------
  145. What: USB driver API moves to EXPORT_SYMBOL_GPL
  146. When: February 2008
  147. Files: include/linux/usb.h, drivers/usb/core/driver.c
  148. Why: The USB subsystem has changed a lot over time, and it has been
  149. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  150. that operate as fast as the USB bus allows. Because of this, the USB
  151. subsystem will not be allowing closed source kernel drivers to
  152. register with it, after this grace period is over. If anyone needs
  153. any help in converting their closed source drivers over to use the
  154. userspace filesystems, please contact the
  155. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  156. there will be glad to help you out.
  157. Who: Greg Kroah-Hartman <gregkh@suse.de>
  158. ---------------------------
  159. What: find_trylock_page
  160. When: January 2007
  161. Why: The interface no longer has any callers left in the kernel. It
  162. is an odd interface (compared with other find_*_page functions), in
  163. that it does not take a refcount to the page, only the page lock.
  164. It should be replaced with find_get_page or find_lock_page if possible.
  165. This feature removal can be reevaluated if users of the interface
  166. cannot cleanly use something else.
  167. Who: Nick Piggin <npiggin@suse.de>
  168. ---------------------------
  169. What: Interrupt only SA_* flags
  170. When: Januar 2007
  171. Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
  172. out of the signal namespace.
  173. Who: Thomas Gleixner <tglx@linutronix.de>
  174. ---------------------------
  175. What: i2c-ite and i2c-algo-ite drivers
  176. When: September 2006
  177. Why: These drivers never compiled since they were added to the kernel
  178. tree 5 years ago. This feature removal can be reevaluated if
  179. someone shows interest in the drivers, fixes them and takes over
  180. maintenance.
  181. http://marc.theaimsgroup.com/?l=linux-mips&m=115040510817448
  182. Who: Jean Delvare <khali@linux-fr.org>
  183. ---------------------------
  184. What: Bridge netfilter deferred IPv4/IPv6 output hook calling
  185. When: January 2007
  186. Why: The deferred output hooks are a layering violation causing unusual
  187. and broken behaviour on bridge devices. Examples of things they
  188. break include QoS classifation using the MARK or CLASSIFY targets,
  189. the IPsec policy match and connection tracking with VLANs on a
  190. bridge. Their only use is to enable bridge output port filtering
  191. within iptables with the physdev match, which can also be done by
  192. combining iptables and ebtables using netfilter marks. Until it
  193. will get removed the hook deferral is disabled by default and is
  194. only enabled when needed.
  195. Who: Patrick McHardy <kaber@trash.net>
  196. ---------------------------
  197. What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
  198. When: October 2008
  199. Why: The stacking of class devices makes these values misleading and
  200. inconsistent.
  201. Class devices should not carry any of these properties, and bus
  202. devices have SUBSYTEM and DRIVER as a replacement.
  203. Who: Kay Sievers <kay.sievers@suse.de>
  204. ---------------------------
  205. What: i2c-isa
  206. When: December 2006
  207. Why: i2c-isa is a non-sense and doesn't fit in the device driver
  208. model. Drivers relying on it are better implemented as platform
  209. drivers.
  210. Who: Jean Delvare <khali@linux-fr.org>
  211. ---------------------------
  212. What: IPv4 only connection tracking/NAT/helpers
  213. When: 2.6.22
  214. Why: The new layer 3 independant connection tracking replaces the old
  215. IPv4 only version. After some stabilization of the new code the
  216. old one will be removed.
  217. Who: Patrick McHardy <kaber@trash.net>
  218. ---------------------------