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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.
7 ---------------------------
9 What: IRQF_SAMPLE_RANDOM
10 Check: IRQF_SAMPLE_RANDOM
11 When: July 2009
13 Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
14 sources in the kernel's current entropy model. To resolve this, every
15 input point to the kernel's entropy pool needs to better document the
16 type of entropy source it actually is. This will be replaced with
17 additional add_*_randomness functions in drivers/char/random.c
19 Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
21 ---------------------------
23 What: The ieee80211_regdom module parameter
24 When: March 2010 / desktop catchup
26 Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
27 and currently serves as an option for users to define an
28 ISO / IEC 3166 alpha2 code for the country they are currently
29 present in. Although there are userspace API replacements for this
30 through nl80211 distributions haven't yet caught up with implementing
31 decent alternatives through standard GUIs. Although available as an
32 option through iw or wpa_supplicant its just a matter of time before
33 distributions pick up good GUI options for this. The ideal solution
34 would actually consist of intelligent designs which would do this for
35 the user automatically even when travelling through different countries.
36 Until then we leave this module parameter as a compromise.
38 When userspace improves with reasonable widely-available alternatives for
39 this we will no longer need this module parameter. This entry hopes that
40 by the super-futuristically looking date of "March 2010" we will have
41 such replacements widely available.
43 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
45 ---------------------------
47 What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information
48 When: March 2010 / desktop catchup
50 Why: The old regulatory infrastructure has been replaced with a new one
51 which does not require statically defined regulatory domains. We do
52 not want to keep static regulatory domains in the kernel due to the
53 the dynamic nature of regulatory law and localization. We kept around
54 the old static definitions for the regulatory domains of:
56 * US
57 * JP
58 * EU
60 and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
61 set. We will remove this option once the standard Linux desktop catches
62 up with the new userspace APIs we have implemented.
64 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
66 ---------------------------
68 What: dev->power.power_state
69 When: July 2007
70 Why: Broken design for runtime control over driver power states, confusing
71 driver-internal runtime power management with: mechanisms to support
72 system-wide sleep state transitions; event codes that distinguish
73 different phases of swsusp "sleep" transitions; and userspace policy
74 inputs. This framework was never widely used, and most attempts to
75 use it were broken. Drivers should instead be exposing domain-specific
76 interfaces either to kernel or to userspace.
77 Who: Pavel Machek <pavel@suse.cz>
79 ---------------------------
81 What: Video4Linux API 1 ioctls and from Video devices.
82 When: July 2009
83 Files: include/linux/videodev.h
84 Check: include/linux/videodev.h
85 Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
86 series. The old API have lots of drawbacks and don't provide enough
87 means to work with all video and audio standards. The newer API is
88 already available on the main drivers and should be used instead.
89 Newer drivers should use v4l_compat_translate_ioctl function to handle
90 old calls, replacing to newer ones.
91 Decoder iocts are using internally to allow video drivers to
92 communicate with video decoders. This should also be improved to allow
93 V4L2 calls being translated into compatible internal ioctls.
94 Compatibility ioctls will be provided, for a while, via
95 v4l1-compat module.
96 Who: Mauro Carvalho Chehab <mchehab@infradead.org>
98 ---------------------------
100 What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
101 When: November 2005
102 Files: drivers/pcmcia/: pcmcia_ioctl.c
103 Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
104 normal hotpluggable bus, and with it using the default kernel
105 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
106 control ioctl needed by cardmgr and cardctl from pcmcia-cs is
107 unnecessary, and makes further cleanups and integration of the
108 PCMCIA subsystem into the Linux kernel device driver model more
109 difficult. The features provided by cardmgr and cardctl are either
110 handled by the kernel itself now or are available in the new
111 pcmciautils package available at
112 http://kernel.org/pub/linux/utils/kernel/pcmcia/
113 Who: Dominik Brodowski <linux@brodo.de>
115 ---------------------------
117 What: sys_sysctl
118 When: September 2010
119 Option: CONFIG_SYSCTL_SYSCALL
120 Why: The same information is available in a more convenient from
121 /proc/sys, and none of the sysctl variables appear to be
122 important performance wise.
124 Binary sysctls are a long standing source of subtle kernel
125 bugs and security issues.
127 When I looked several months ago all I could find after
128 searching several distributions were 5 user space programs and
129 glibc (which falls back to /proc/sys) using this syscall.
131 The man page for sysctl(2) documents it as unusable for user
132 space programs.
134 sysctl(2) is not generally ABI compatible to a 32bit user
135 space application on a 64bit and a 32bit kernel.
137 For the last several months the policy has been no new binary
138 sysctls and no one has put forward an argument to use them.
140 Binary sysctls issues seem to keep happening appearing so
141 properly deprecating them (with a warning to user space) and a
142 2 year grace warning period will mean eventually we can kill
143 them and end the pain.
145 In the mean time individual binary sysctls can be dealt with
146 in a piecewise fashion.
148 Who: Eric Biederman <ebiederm@xmission.com>
150 ---------------------------
152 What: remove EXPORT_SYMBOL(kernel_thread)
153 When: August 2006
154 Files: arch/*/kernel/*_ksyms.c
155 Check: kernel_thread
156 Why: kernel_thread is a low-level implementation detail. Drivers should
157 use the <linux/kthread.h> API instead which shields them from
158 implementation details and provides a higherlevel interface that
159 prevents bugs and code duplication
160 Who: Christoph Hellwig <hch@lst.de>
162 ---------------------------
164 What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
165 (temporary transition config option provided until then)
166 The transition config option will also be removed at the same time.
167 When: before 2.6.19
168 Why: Unused symbols are both increasing the size of the kernel binary
169 and are often a sign of "wrong API"
170 Who: Arjan van de Ven <arjan@linux.intel.com>
172 ---------------------------
174 What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
175 When: October 2008
176 Why: The stacking of class devices makes these values misleading and
177 inconsistent.
178 Class devices should not carry any of these properties, and bus
179 devices have SUBSYTEM and DRIVER as a replacement.
180 Who: Kay Sievers <kay.sievers@suse.de>
182 ---------------------------
184 What: ACPI procfs interface
185 When: July 2008
186 Why: ACPI sysfs conversion should be finished by January 2008.
187 ACPI procfs interface will be removed in July 2008 so that
188 there is enough time for the user space to catch up.
189 Who: Zhang Rui <rui.zhang@intel.com>
191 ---------------------------
193 What: /proc/acpi/button
194 When: August 2007
195 Why: /proc/acpi/button has been replaced by events to the input layer
196 since 2.6.20.
197 Who: Len Brown <len.brown@intel.com>
199 ---------------------------
201 What: /proc/acpi/event
202 When: February 2008
203 Why: /proc/acpi/event has been replaced by events via the input layer
204 and netlink since 2.6.23.
205 Who: Len Brown <len.brown@intel.com>
207 ---------------------------
209 What: libata spindown skipping and warning
210 When: Dec 2008
211 Why: Some halt(8) implementations synchronize caches for and spin
212 down libata disks because libata didn't use to spin down disk on
213 system halt (only synchronized caches).
214 Spin down on system halt is now implemented. sysfs node
215 /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
216 spin down support is available.
217 Because issuing spin down command to an already spun down disk
218 makes some disks spin up just to spin down again, libata tracks
219 device spindown status to skip the extra spindown command and
220 warn about it.
221 This is to give userspace tools the time to get updated and will
222 be removed after userspace is reasonably updated.
223 Who: Tejun Heo <htejun@gmail.com>
225 ---------------------------
227 What: i386/x86_64 bzImage symlinks
228 When: April 2010
230 Why: The i386/x86_64 merge provides a symlink to the old bzImage
231 location so not yet updated user space tools, e.g. package
232 scripts, do not break.
233 Who: Thomas Gleixner <tglx@linutronix.de>
235 ---------------------------
237 What (Why):
238 - include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
239 (superseded by xt_TOS/xt_tos target & match)
241 - "forwarding" header files like ipt_mac.h in
242 include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/
244 - xt_CONNMARK match revision 0
245 (superseded by xt_CONNMARK match revision 1)
247 - xt_MARK target revisions 0 and 1
248 (superseded by xt_MARK match revision 2)
250 - xt_connmark match revision 0
251 (superseded by xt_connmark match revision 1)
253 - xt_conntrack match revision 0
254 (superseded by xt_conntrack match revision 1)
256 - xt_iprange match revision 0,
257 include/linux/netfilter_ipv4/ipt_iprange.h
258 (superseded by xt_iprange match revision 1)
260 - xt_mark match revision 0
261 (superseded by xt_mark match revision 1)
263 - xt_recent: the old ipt_recent proc dir
264 (superseded by /proc/net/xt_recent)
266 When: January 2009 or Linux 2.7.0, whichever comes first
267 Why: Superseded by newer revisions or modules
268 Who: Jan Engelhardt <jengelh@computergmbh.de>
270 ---------------------------
272 What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
273 When: February 2010
274 Why: All callers should use explicit gpio_request()/gpio_free().
275 The autorequest mechanism in gpiolib was provided mostly as a
276 migration aid for legacy GPIO interfaces (for SOC based GPIOs).
277 Those users have now largely migrated. Platforms implementing
278 the GPIO interfaces without using gpiolib will see no changes.
279 Who: David Brownell <dbrownell@users.sourceforge.net>
280 ---------------------------
282 What: b43 support for firmware revision < 410
283 When: The schedule was July 2008, but it was decided that we are going to keep the
284 code as long as there are no major maintanance headaches.
285 So it _could_ be removed _any_ time now, if it conflicts with something new.
286 Why: The support code for the old firmware hurts code readability/maintainability
287 and slightly hurts runtime performance. Bugfixes for the old firmware
288 are not provided by Broadcom anymore.
289 Who: Michael Buesch <mb@bu3sch.de>
291 ---------------------------
293 What: usedac i386 kernel parameter
294 When: 2.6.27
295 Why: replaced by allowdac and no dac combination
296 Who: Glauber Costa <gcosta@redhat.com>
298 ---------------------------
300 What: print_fn_descriptor_symbol()
301 When: October 2009
302 Why: The %pF vsprintf format provides the same functionality in a
303 simpler way. print_fn_descriptor_symbol() is deprecated but
304 still present to give out-of-tree modules time to change.
305 Who: Bjorn Helgaas <bjorn.helgaas@hp.com>
307 ---------------------------
309 What: /sys/o2cb symlink
310 When: January 2010
311 Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
312 exists as a symlink for backwards compatibility for old versions of
313 ocfs2-tools. 2 years should be sufficient time to phase in new versions
314 which know to look in /sys/fs/o2cb.
315 Who: ocfs2-devel@oss.oracle.com
317 ---------------------------
319 What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
320 SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
321 When: June 2009
322 Why: A newer version of the options have been introduced in 2005 that
323 removes the limitions of the old API. The sctp library has been
324 converted to use these new options at the same time. Any user
325 space app that directly uses the old options should convert to using
326 the new options.
327 Who: Vlad Yasevich <vladislav.yasevich@hp.com>
329 ---------------------------
331 What: Ability for non root users to shm_get hugetlb pages based on mlock
332 resource limits
333 When: 2.6.31
334 Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
335 have CAP_IPC_LOCK to be able to allocate shm segments backed by
336 huge pages. The mlock based rlimit check to allow shm hugetlb is
337 inconsistent with mmap based allocations. Hence it is being
338 deprecated.
339 Who: Ravikiran Thirumalai <kiran@scalex86.org>
341 ---------------------------
343 What: CONFIG_THERMAL_HWMON
344 When: January 2009
345 Why: This option was introduced just to allow older lm-sensors userspace
346 to keep working over the upgrade to 2.6.26. At the scheduled time of
347 removal fixed lm-sensors (2.x or 3.x) should be readily available.
348 Who: Rene Herman <rene.herman@gmail.com>
350 ---------------------------
352 What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
353 (in net/core/net-sysfs.c)
354 When: After the only user (hal) has seen a release with the patches
355 for enough time, probably some time in 2010.
356 Why: Over 1K .text/.data size reduction, data is available in other
357 ways (ioctls)
358 Who: Johannes Berg <johannes@sipsolutions.net>
360 ---------------------------
362 What: CONFIG_NF_CT_ACCT
363 When: 2.6.29
364 Why: Accounting can now be enabled/disabled without kernel recompilation.
365 Currently used only to set a default value for a feature that is also
366 controlled by a kernel/module/sysfs/sysctl parameter.
367 Who: Krzysztof Piotr Oledzki <ole@ans.pl>
369 ---------------------------
371 What: fscher and fscpos drivers
372 When: June 2009
373 Why: Deprecated by the new fschmd driver.
374 Who: Hans de Goede <hdegoede@redhat.com>
375 Jean Delvare <khali@linux-fr.org>
377 ---------------------------
379 What: sysfs ui for changing p4-clockmod parameters
380 When: September 2009
381 Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
382 e088e4c9cdb618675874becb91b2fd581ee707e6.
383 Removal is subject to fixing any remaining bugs in ACPI which may
384 cause the thermal throttling not to happen at the right time.
385 Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
387 -----------------------------
389 What: __do_IRQ all in one fits nothing interrupt handler
390 When: 2.6.32
391 Why: __do_IRQ was kept for easy migration to the type flow handlers.
392 More than two years of migration time is enough.
393 Who: Thomas Gleixner <tglx@linutronix.de>
395 -----------------------------
397 What: obsolete generic irq defines and typedefs
398 When: 2.6.30
399 Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
400 have been kept around for migration reasons. After more than two years
401 it's time to remove them finally
402 Who: Thomas Gleixner <tglx@linutronix.de>
404 ---------------------------
406 What: fakephp and associated sysfs files in /sys/bus/pci/slots/
407 When: 2011
408 Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
409 represent a machine's physical PCI slots. The change in semantics
410 had userspace implications, as the hotplug core no longer allowed
411 drivers to create multiple sysfs files per physical slot (required
412 for multi-function devices, e.g.). fakephp was seen as a developer's
413 tool only, and its interface changed. Too late, we learned that
414 there were some users of the fakephp interface.
416 In 2.6.30, the original fakephp interface was restored. At the same
417 time, the PCI core gained the ability that fakephp provided, namely
418 function-level hot-remove and hot-add.
420 Since the PCI core now provides the same functionality, exposed in:
422 /sys/bus/pci/rescan
423 /sys/bus/pci/devices/.../remove
424 /sys/bus/pci/devices/.../rescan
426 there is no functional reason to maintain fakephp as well.
428 We will keep the existing module so that 'modprobe fakephp' will
429 present the old /sys/bus/pci/slots/... interface for compatibility,
430 but users are urged to migrate their applications to the API above.
432 After a reasonable transition period, we will remove the legacy
433 fakephp interface.
434 Who: Alex Chiang <achiang@hp.com>
436 ---------------------------
438 What: i2c-voodoo3 driver
439 When: October 2009
440 Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate
441 driver but this caused driver conflicts.
442 Who: Jean Delvare <khali@linux-fr.org>
443 Krzysztof Helt <krzysztof.h1@wp.pl>
445 ---------------------------
447 What: CONFIG_RFKILL_INPUT
448 When: 2.6.33
449 Why: Should be implemented in userspace, policy daemon.
450 Who: Johannes Berg <johannes@sipsolutions.net>
452 ----------------------------
454 What: CONFIG_X86_OLD_MCE
455 When: 2.6.32
456 Why: Remove the old legacy 32bit machine check code. This has been
457 superseded by the newer machine check code from the 64bit port,
458 but the old version has been kept around for easier testing. Note this
459 doesn't impact the old P5 and WinChip machine check handlers.
460 Who: Andi Kleen <andi@firstfloor.org>
462 ----------------------------
464 What: lock_policy_rwsem_* and unlock_policy_rwsem_* will not be
465 exported interface anymore.
466 When: 2.6.33
467 Why: cpu_policy_rwsem has a new cleaner definition making it local to
468 cpufreq core and contained inside cpufreq.c. Other dependent
469 drivers should not use it in order to safely avoid lockdep issues.
470 Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>