feature-removal-schedule.txt 9.9 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: November 2006
  28. Why: Deprecated in favour of the new ioctl-based rawiso interface, which is
  29. more efficient. You should really be using libraw1394 for raw1394
  30. access anyway.
  31. Who: Jody McIntyre <scjody@modernduck.com>
  32. ---------------------------
  33. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  34. When: December 2006
  35. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  36. series. The old API have lots of drawbacks and don't provide enough
  37. means to work with all video and audio standards. The newer API is
  38. already available on the main drivers and should be used instead.
  39. Newer drivers should use v4l_compat_translate_ioctl function to handle
  40. old calls, replacing to newer ones.
  41. Decoder iocts are using internally to allow video drivers to
  42. communicate with video decoders. This should also be improved to allow
  43. V4L2 calls being translated into compatible internal ioctls.
  44. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  45. ---------------------------
  46. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  47. When: November 2005
  48. Files: drivers/pcmcia/: pcmcia_ioctl.c
  49. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  50. normal hotpluggable bus, and with it using the default kernel
  51. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  52. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  53. unnecessary, and makes further cleanups and integration of the
  54. PCMCIA subsystem into the Linux kernel device driver model more
  55. difficult. The features provided by cardmgr and cardctl are either
  56. handled by the kernel itself now or are available in the new
  57. pcmciautils package available at
  58. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  59. Who: Dominik Brodowski <linux@brodo.de>
  60. ---------------------------
  61. What: ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
  62. When: December 2005
  63. Why: This interface has been obsoleted by the new layer3-independent
  64. "nfnetlink_queue". The Kernel interface is compatible, so the old
  65. ip[6]tables "QUEUE" targets still work and will transparently handle
  66. all packets into nfnetlink queue number 0. Userspace users will have
  67. to link against API-compatible library on top of libnfnetlink_queue
  68. instead of the current 'libipq'.
  69. Who: Harald Welte <laforge@netfilter.org>
  70. ---------------------------
  71. What: remove EXPORT_SYMBOL(kernel_thread)
  72. When: August 2006
  73. Files: arch/*/kernel/*_ksyms.c
  74. Why: kernel_thread is a low-level implementation detail. Drivers should
  75. use the <linux/kthread.h> API instead which shields them from
  76. implementation details and provides a higherlevel interface that
  77. prevents bugs and code duplication
  78. Who: Christoph Hellwig <hch@lst.de>
  79. ---------------------------
  80. What: CONFIG_FORCED_INLINING
  81. When: June 2006
  82. Why: Config option is there to see if gcc is good enough. (in january
  83. 2006). If it is, the behavior should just be the default. If it's not,
  84. the option should just go away entirely.
  85. Who: Arjan van de Ven
  86. ---------------------------
  87. What: eepro100 network driver
  88. When: January 2007
  89. Why: replaced by the e100 driver
  90. Who: Adrian Bunk <bunk@stusta.de>
  91. ---------------------------
  92. What: drivers depending on OSS_OBSOLETE_DRIVER
  93. When: options in 2.6.20, code in 2.6.22
  94. Why: OSS drivers with ALSA replacements
  95. Who: Adrian Bunk <bunk@stusta.de>
  96. ---------------------------
  97. What: pci_module_init(driver)
  98. When: January 2007
  99. Why: Is replaced by pci_register_driver(pci_driver).
  100. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  101. ---------------------------
  102. What: Usage of invalid timevals in setitimer
  103. When: March 2007
  104. Why: POSIX requires to validate timevals in the setitimer call. This
  105. was never done by Linux. The invalid (e.g. negative timevals) were
  106. silently converted to more or less random timeouts and intervals.
  107. Until the removal a per boot limited number of warnings is printed
  108. and the timevals are sanitized.
  109. Who: Thomas Gleixner <tglx@linutronix.de>
  110. ---------------------------
  111. What: I2C interface of the it87 driver
  112. When: January 2007
  113. Why: The ISA interface is faster and should be always available. The I2C
  114. probing is also known to cause trouble in at least one case (see
  115. bug #5889.)
  116. Who: Jean Delvare <khali@linux-fr.org>
  117. ---------------------------
  118. What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
  119. (temporary transition config option provided until then)
  120. The transition config option will also be removed at the same time.
  121. When: before 2.6.19
  122. Why: Unused symbols are both increasing the size of the kernel binary
  123. and are often a sign of "wrong API"
  124. Who: Arjan van de Ven <arjan@linux.intel.com>
  125. ---------------------------
  126. What: mount/umount uevents
  127. When: February 2007
  128. Why: These events are not correct, and do not properly let userspace know
  129. when a file system has been mounted or unmounted. Userspace should
  130. poll the /proc/mounts file instead to detect this properly.
  131. Who: Greg Kroah-Hartman <gregkh@suse.de>
  132. ---------------------------
  133. What: USB driver API moves to EXPORT_SYMBOL_GPL
  134. When: February 2008
  135. Files: include/linux/usb.h, drivers/usb/core/driver.c
  136. Why: The USB subsystem has changed a lot over time, and it has been
  137. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  138. that operate as fast as the USB bus allows. Because of this, the USB
  139. subsystem will not be allowing closed source kernel drivers to
  140. register with it, after this grace period is over. If anyone needs
  141. any help in converting their closed source drivers over to use the
  142. userspace filesystems, please contact the
  143. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  144. there will be glad to help you out.
  145. Who: Greg Kroah-Hartman <gregkh@suse.de>
  146. ---------------------------
  147. What: find_trylock_page
  148. When: January 2007
  149. Why: The interface no longer has any callers left in the kernel. It
  150. is an odd interface (compared with other find_*_page functions), in
  151. that it does not take a refcount to the page, only the page lock.
  152. It should be replaced with find_get_page or find_lock_page if possible.
  153. This feature removal can be reevaluated if users of the interface
  154. cannot cleanly use something else.
  155. Who: Nick Piggin <npiggin@suse.de>
  156. ---------------------------
  157. What: Interrupt only SA_* flags
  158. When: Januar 2007
  159. Why: The interrupt related SA_* flags are replaced by IRQF_* to move them
  160. out of the signal namespace.
  161. Who: Thomas Gleixner <tglx@linutronix.de>
  162. ---------------------------
  163. What: i2c-ite and i2c-algo-ite drivers
  164. When: September 2006
  165. Why: These drivers never compiled since they were added to the kernel
  166. tree 5 years ago. This feature removal can be reevaluated if
  167. someone shows interest in the drivers, fixes them and takes over
  168. maintenance.
  169. http://marc.theaimsgroup.com/?l=linux-mips&m=115040510817448
  170. Who: Jean Delvare <khali@linux-fr.org>
  171. ---------------------------
  172. What: Bridge netfilter deferred IPv4/IPv6 output hook calling
  173. When: January 2007
  174. Why: The deferred output hooks are a layering violation causing unusual
  175. and broken behaviour on bridge devices. Examples of things they
  176. break include QoS classifation using the MARK or CLASSIFY targets,
  177. the IPsec policy match and connection tracking with VLANs on a
  178. bridge. Their only use is to enable bridge output port filtering
  179. within iptables with the physdev match, which can also be done by
  180. combining iptables and ebtables using netfilter marks. Until it
  181. will get removed the hook deferral is disabled by default and is
  182. only enabled when needed.
  183. Who: Patrick McHardy <kaber@trash.net>
  184. ---------------------------
  185. What: frame diverter
  186. When: November 2006
  187. Why: The frame diverter is included in most distribution kernels, but is
  188. broken. It does not correctly handle many things:
  189. - IPV6
  190. - non-linear skb's
  191. - network device RCU on removal
  192. - input frames not correctly checked for protocol errors
  193. It also adds allocation overhead even if not enabled.
  194. It is not clear if anyone is still using it.
  195. Who: Stephen Hemminger <shemminger@osdl.org>
  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: ftape
  213. When: 2.6.20
  214. Why: Orphaned for ages. SMP bugs long unfixed. Few users left
  215. in the world.
  216. Who: Jeff Garzik <jeff@garzik.org>
  217. ---------------------------