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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: The ieee80211_regdom module parameter
10 When: March 2010 / desktop catchup
12 Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
13 and currently serves as an option for users to define an
14 ISO / IEC 3166 alpha2 code for the country they are currently
15 present in. Although there are userspace API replacements for this
16 through nl80211 distributions haven't yet caught up with implementing
17 decent alternatives through standard GUIs. Although available as an
18 option through iw or wpa_supplicant its just a matter of time before
19 distributions pick up good GUI options for this. The ideal solution
20 would actually consist of intelligent designs which would do this for
21 the user automatically even when travelling through different countries.
22 Until then we leave this module parameter as a compromise.
24 When userspace improves with reasonable widely-available alternatives for
25 this we will no longer need this module parameter. This entry hopes that
26 by the super-futuristically looking date of "March 2010" we will have
27 such replacements widely available.
29 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
31 ---------------------------
33 What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information
34 When: March 2010 / desktop catchup
36 Why: The old regulatory infrastructure has been replaced with a new one
37 which does not require statically defined regulatory domains. We do
38 not want to keep static regulatory domains in the kernel due to the
39 the dynamic nature of regulatory law and localization. We kept around
40 the old static definitions for the regulatory domains of:
42 * US
43 * JP
44 * EU
46 and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
47 set. We will remove this option once the standard Linux desktop catches
48 up with the new userspace APIs we have implemented.
50 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
52 ---------------------------
54 What: dev->power.power_state
55 When: July 2007
56 Why: Broken design for runtime control over driver power states, confusing
57 driver-internal runtime power management with: mechanisms to support
58 system-wide sleep state transitions; event codes that distinguish
59 different phases of swsusp "sleep" transitions; and userspace policy
60 inputs. This framework was never widely used, and most attempts to
61 use it were broken. Drivers should instead be exposing domain-specific
62 interfaces either to kernel or to userspace.
63 Who: Pavel Machek <pavel@suse.cz>
65 ---------------------------
67 What: Video4Linux API 1 ioctls and from Video devices.
68 When: July 2009
69 Files: include/linux/videodev.h
70 Check: include/linux/videodev.h
71 Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
72 series. The old API have lots of drawbacks and don't provide enough
73 means to work with all video and audio standards. The newer API is
74 already available on the main drivers and should be used instead.
75 Newer drivers should use v4l_compat_translate_ioctl function to handle
76 old calls, replacing to newer ones.
77 Decoder iocts are using internally to allow video drivers to
78 communicate with video decoders. This should also be improved to allow
79 V4L2 calls being translated into compatible internal ioctls.
80 Compatibility ioctls will be provided, for a while, via
81 v4l1-compat module.
82 Who: Mauro Carvalho Chehab <mchehab@infradead.org>
84 ---------------------------
86 What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
87 When: November 2005
88 Files: drivers/pcmcia/: pcmcia_ioctl.c
89 Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
90 normal hotpluggable bus, and with it using the default kernel
91 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
92 control ioctl needed by cardmgr and cardctl from pcmcia-cs is
93 unnecessary, and makes further cleanups and integration of the
94 PCMCIA subsystem into the Linux kernel device driver model more
95 difficult. The features provided by cardmgr and cardctl are either
96 handled by the kernel itself now or are available in the new
97 pcmciautils package available at
98 http://kernel.org/pub/linux/utils/kernel/pcmcia/
99 Who: Dominik Brodowski <linux@brodo.de>
101 ---------------------------
103 What: sys_sysctl
104 When: September 2010
105 Option: CONFIG_SYSCTL_SYSCALL
106 Why: The same information is available in a more convenient from
107 /proc/sys, and none of the sysctl variables appear to be
108 important performance wise.
110 Binary sysctls are a long standing source of subtle kernel
111 bugs and security issues.
113 When I looked several months ago all I could find after
114 searching several distributions were 5 user space programs and
115 glibc (which falls back to /proc/sys) using this syscall.
117 The man page for sysctl(2) documents it as unusable for user
118 space programs.
120 sysctl(2) is not generally ABI compatible to a 32bit user
121 space application on a 64bit and a 32bit kernel.
123 For the last several months the policy has been no new binary
124 sysctls and no one has put forward an argument to use them.
126 Binary sysctls issues seem to keep happening appearing so
127 properly deprecating them (with a warning to user space) and a
128 2 year grace warning period will mean eventually we can kill
129 them and end the pain.
131 In the mean time individual binary sysctls can be dealt with
132 in a piecewise fashion.
134 Who: Eric Biederman <ebiederm@xmission.com>
136 ---------------------------
138 What: remove EXPORT_SYMBOL(kernel_thread)
139 When: August 2006
140 Files: arch/*/kernel/*_ksyms.c
141 Check: kernel_thread
142 Why: kernel_thread is a low-level implementation detail. Drivers should
143 use the <linux/kthread.h> API instead which shields them from
144 implementation details and provides a higherlevel interface that
145 prevents bugs and code duplication
146 Who: Christoph Hellwig <hch@lst.de>
148 ---------------------------
150 What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
151 (temporary transition config option provided until then)
152 The transition config option will also be removed at the same time.
153 When: before 2.6.19
154 Why: Unused symbols are both increasing the size of the kernel binary
155 and are often a sign of "wrong API"
156 Who: Arjan van de Ven <arjan@linux.intel.com>
158 ---------------------------
160 What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
161 When: October 2008
162 Why: The stacking of class devices makes these values misleading and
163 inconsistent.
164 Class devices should not carry any of these properties, and bus
165 devices have SUBSYTEM and DRIVER as a replacement.
166 Who: Kay Sievers <kay.sievers@suse.de>
168 ---------------------------
170 What: ACPI procfs interface
171 When: July 2008
172 Why: ACPI sysfs conversion should be finished by January 2008.
173 ACPI procfs interface will be removed in July 2008 so that
174 there is enough time for the user space to catch up.
175 Who: Zhang Rui <rui.zhang@intel.com>
177 ---------------------------
179 What: /proc/acpi/button
180 When: August 2007
181 Why: /proc/acpi/button has been replaced by events to the input layer
182 since 2.6.20.
183 Who: Len Brown <len.brown@intel.com>
185 ---------------------------
187 What: /proc/acpi/event
188 When: February 2008
189 Why: /proc/acpi/event has been replaced by events via the input layer
190 and netlink since 2.6.23.
191 Who: Len Brown <len.brown@intel.com>
193 ---------------------------
195 What: libata spindown skipping and warning
196 When: Dec 2008
197 Why: Some halt(8) implementations synchronize caches for and spin
198 down libata disks because libata didn't use to spin down disk on
199 system halt (only synchronized caches).
200 Spin down on system halt is now implemented. sysfs node
201 /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
202 spin down support is available.
203 Because issuing spin down command to an already spun down disk
204 makes some disks spin up just to spin down again, libata tracks
205 device spindown status to skip the extra spindown command and
206 warn about it.
207 This is to give userspace tools the time to get updated and will
208 be removed after userspace is reasonably updated.
209 Who: Tejun Heo <htejun@gmail.com>
211 ---------------------------
213 What: i386/x86_64 bzImage symlinks
214 When: April 2010
216 Why: The i386/x86_64 merge provides a symlink to the old bzImage
217 location so not yet updated user space tools, e.g. package
218 scripts, do not break.
219 Who: Thomas Gleixner <tglx@linutronix.de>
221 ---------------------------
223 What (Why):
224 - include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
225 (superseded by xt_TOS/xt_tos target & match)
227 - "forwarding" header files like ipt_mac.h in
228 include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/
230 - xt_CONNMARK match revision 0
231 (superseded by xt_CONNMARK match revision 1)
233 - xt_MARK target revisions 0 and 1
234 (superseded by xt_MARK match revision 2)
236 - xt_connmark match revision 0
237 (superseded by xt_connmark match revision 1)
239 - xt_conntrack match revision 0
240 (superseded by xt_conntrack match revision 1)
242 - xt_iprange match revision 0,
243 include/linux/netfilter_ipv4/ipt_iprange.h
244 (superseded by xt_iprange match revision 1)
246 - xt_mark match revision 0
247 (superseded by xt_mark match revision 1)
249 - xt_recent: the old ipt_recent proc dir
250 (superseded by /proc/net/xt_recent)
252 When: January 2009 or Linux 2.7.0, whichever comes first
253 Why: Superseded by newer revisions or modules
254 Who: Jan Engelhardt <jengelh@computergmbh.de>
256 ---------------------------
258 What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
259 When: February 2010
260 Why: All callers should use explicit gpio_request()/gpio_free().
261 The autorequest mechanism in gpiolib was provided mostly as a
262 migration aid for legacy GPIO interfaces (for SOC based GPIOs).
263 Those users have now largely migrated. Platforms implementing
264 the GPIO interfaces without using gpiolib will see no changes.
265 Who: David Brownell <dbrownell@users.sourceforge.net>
266 ---------------------------
268 What: b43 support for firmware revision < 410
269 When: The schedule was July 2008, but it was decided that we are going to keep the
270 code as long as there are no major maintanance headaches.
271 So it _could_ be removed _any_ time now, if it conflicts with something new.
272 Why: The support code for the old firmware hurts code readability/maintainability
273 and slightly hurts runtime performance. Bugfixes for the old firmware
274 are not provided by Broadcom anymore.
275 Who: Michael Buesch <mb@bu3sch.de>
277 ---------------------------
279 What: usedac i386 kernel parameter
280 When: 2.6.27
281 Why: replaced by allowdac and no dac combination
282 Who: Glauber Costa <gcosta@redhat.com>
284 ---------------------------
286 What: remove HID compat support
287 When: 2.6.29
288 Why: needed only as a temporary solution until distros fix themselves up
289 Who: Jiri Slaby <jirislaby@gmail.com>
291 ---------------------------
293 What: print_fn_descriptor_symbol()
294 When: October 2009
295 Why: The %pF vsprintf format provides the same functionality in a
296 simpler way. print_fn_descriptor_symbol() is deprecated but
297 still present to give out-of-tree modules time to change.
298 Who: Bjorn Helgaas <bjorn.helgaas@hp.com>
300 ---------------------------
302 What: /sys/o2cb symlink
303 When: January 2010
304 Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
305 exists as a symlink for backwards compatibility for old versions of
306 ocfs2-tools. 2 years should be sufficient time to phase in new versions
307 which know to look in /sys/fs/o2cb.
308 Who: ocfs2-devel@oss.oracle.com
310 ---------------------------
312 What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
313 SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
314 When: June 2009
315 Why: A newer version of the options have been introduced in 2005 that
316 removes the limitions of the old API. The sctp library has been
317 converted to use these new options at the same time. Any user
318 space app that directly uses the old options should convert to using
319 the new options.
320 Who: Vlad Yasevich <vladislav.yasevich@hp.com>
322 ---------------------------
324 What: Ability for non root users to shm_get hugetlb pages based on mlock
325 resource limits
326 When: 2.6.31
327 Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
328 have CAP_IPC_LOCK to be able to allocate shm segments backed by
329 huge pages. The mlock based rlimit check to allow shm hugetlb is
330 inconsistent with mmap based allocations. Hence it is being
331 deprecated.
332 Who: Ravikiran Thirumalai <kiran@scalex86.org>
334 ---------------------------
336 What: CONFIG_THERMAL_HWMON
337 When: January 2009
338 Why: This option was introduced just to allow older lm-sensors userspace
339 to keep working over the upgrade to 2.6.26. At the scheduled time of
340 removal fixed lm-sensors (2.x or 3.x) should be readily available.
341 Who: Rene Herman <rene.herman@gmail.com>
343 ---------------------------
345 What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
346 (in net/core/net-sysfs.c)
347 When: After the only user (hal) has seen a release with the patches
348 for enough time, probably some time in 2010.
349 Why: Over 1K .text/.data size reduction, data is available in other
350 ways (ioctls)
351 Who: Johannes Berg <johannes@sipsolutions.net>
353 ---------------------------
355 What: CONFIG_NF_CT_ACCT
356 When: 2.6.29
357 Why: Accounting can now be enabled/disabled without kernel recompilation.
358 Currently used only to set a default value for a feature that is also
359 controlled by a kernel/module/sysfs/sysctl parameter.
360 Who: Krzysztof Piotr Oledzki <ole@ans.pl>
362 ---------------------------
364 What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client()
365 When: 2.6.30
366 Check: i2c_attach_client i2c_detach_client
367 Why: Deprecated by the new (standard) device driver binding model. Use
368 i2c_driver->probe() and ->remove() instead.
369 Who: Jean Delvare <khali@linux-fr.org>
371 ---------------------------
373 What: fscher and fscpos drivers
374 When: June 2009
375 Why: Deprecated by the new fschmd driver.
376 Who: Hans de Goede <hdegoede@redhat.com>
377 Jean Delvare <khali@linux-fr.org>
379 ---------------------------
381 What: sysfs ui for changing p4-clockmod parameters
382 When: September 2009
383 Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
384 e088e4c9cdb618675874becb91b2fd581ee707e6.
385 Removal is subject to fixing any remaining bugs in ACPI which may
386 cause the thermal throttling not to happen at the right time.
387 Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
389 -----------------------------
391 What: __do_IRQ all in one fits nothing interrupt handler
392 When: 2.6.32
393 Why: __do_IRQ was kept for easy migration to the type flow handlers.
394 More than two years of migration time is enough.
395 Who: Thomas Gleixner <tglx@linutronix.de>
397 -----------------------------
399 What: obsolete generic irq defines and typedefs
400 When: 2.6.30
401 Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
402 have been kept around for migration reasons. After more than two years
403 it's time to remove them finally
404 Who: Thomas Gleixner <tglx@linutronix.de>
406 ---------------------------
408 What: fakephp and associated sysfs files in /sys/bus/pci/slots/
409 When: 2011
410 Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
411 represent a machine's physical PCI slots. The change in semantics
412 had userspace implications, as the hotplug core no longer allowed
413 drivers to create multiple sysfs files per physical slot (required
414 for multi-function devices, e.g.). fakephp was seen as a developer's
415 tool only, and its interface changed. Too late, we learned that
416 there were some users of the fakephp interface.
418 In 2.6.30, the original fakephp interface was restored. At the same
419 time, the PCI core gained the ability that fakephp provided, namely
420 function-level hot-remove and hot-add.
422 Since the PCI core now provides the same functionality, exposed in:
424 /sys/bus/pci/rescan
425 /sys/bus/pci/devices/.../remove
426 /sys/bus/pci/devices/.../rescan
428 there is no functional reason to maintain fakephp as well.
430 We will keep the existing module so that 'modprobe fakephp' will
431 present the old /sys/bus/pci/slots/... interface for compatibility,
432 but users are urged to migrate their applications to the API above.
434 After a reasonable transition period, we will remove the legacy
435 fakephp interface.
436 Who: Alex Chiang <achiang@hp.com>