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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: print_fn_descriptor_symbol()
287 When: October 2009
288 Why: The %pF vsprintf format provides the same functionality in a
289 simpler way. print_fn_descriptor_symbol() is deprecated but
290 still present to give out-of-tree modules time to change.
291 Who: Bjorn Helgaas <bjorn.helgaas@hp.com>
293 ---------------------------
295 What: /sys/o2cb symlink
296 When: January 2010
297 Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
298 exists as a symlink for backwards compatibility for old versions of
299 ocfs2-tools. 2 years should be sufficient time to phase in new versions
300 which know to look in /sys/fs/o2cb.
301 Who: ocfs2-devel@oss.oracle.com
303 ---------------------------
305 What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
306 SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
307 When: June 2009
308 Why: A newer version of the options have been introduced in 2005 that
309 removes the limitions of the old API. The sctp library has been
310 converted to use these new options at the same time. Any user
311 space app that directly uses the old options should convert to using
312 the new options.
313 Who: Vlad Yasevich <vladislav.yasevich@hp.com>
315 ---------------------------
317 What: Ability for non root users to shm_get hugetlb pages based on mlock
318 resource limits
319 When: 2.6.31
320 Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
321 have CAP_IPC_LOCK to be able to allocate shm segments backed by
322 huge pages. The mlock based rlimit check to allow shm hugetlb is
323 inconsistent with mmap based allocations. Hence it is being
324 deprecated.
325 Who: Ravikiran Thirumalai <kiran@scalex86.org>
327 ---------------------------
329 What: CONFIG_THERMAL_HWMON
330 When: January 2009
331 Why: This option was introduced just to allow older lm-sensors userspace
332 to keep working over the upgrade to 2.6.26. At the scheduled time of
333 removal fixed lm-sensors (2.x or 3.x) should be readily available.
334 Who: Rene Herman <rene.herman@gmail.com>
336 ---------------------------
338 What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
339 (in net/core/net-sysfs.c)
340 When: After the only user (hal) has seen a release with the patches
341 for enough time, probably some time in 2010.
342 Why: Over 1K .text/.data size reduction, data is available in other
343 ways (ioctls)
344 Who: Johannes Berg <johannes@sipsolutions.net>
346 ---------------------------
348 What: CONFIG_NF_CT_ACCT
349 When: 2.6.29
350 Why: Accounting can now be enabled/disabled without kernel recompilation.
351 Currently used only to set a default value for a feature that is also
352 controlled by a kernel/module/sysfs/sysctl parameter.
353 Who: Krzysztof Piotr Oledzki <ole@ans.pl>
355 ---------------------------
357 What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client(),
358 i2c_adapter->client_register(), i2c_adapter->client_unregister
359 When: 2.6.30
360 Check: i2c_attach_client i2c_detach_client
361 Why: Deprecated by the new (standard) device driver binding model. Use
362 i2c_driver->probe() and ->remove() instead.
363 Who: Jean Delvare <khali@linux-fr.org>
365 ---------------------------
367 What: fscher and fscpos drivers
368 When: June 2009
369 Why: Deprecated by the new fschmd driver.
370 Who: Hans de Goede <hdegoede@redhat.com>
371 Jean Delvare <khali@linux-fr.org>
373 ---------------------------
375 What: sysfs ui for changing p4-clockmod parameters
376 When: September 2009
377 Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
378 e088e4c9cdb618675874becb91b2fd581ee707e6.
379 Removal is subject to fixing any remaining bugs in ACPI which may
380 cause the thermal throttling not to happen at the right time.
381 Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
383 -----------------------------
385 What: __do_IRQ all in one fits nothing interrupt handler
386 When: 2.6.32
387 Why: __do_IRQ was kept for easy migration to the type flow handlers.
388 More than two years of migration time is enough.
389 Who: Thomas Gleixner <tglx@linutronix.de>
391 -----------------------------
393 What: obsolete generic irq defines and typedefs
394 When: 2.6.30
395 Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
396 have been kept around for migration reasons. After more than two years
397 it's time to remove them finally
398 Who: Thomas Gleixner <tglx@linutronix.de>
400 ---------------------------
402 What: fakephp and associated sysfs files in /sys/bus/pci/slots/
403 When: 2011
404 Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
405 represent a machine's physical PCI slots. The change in semantics
406 had userspace implications, as the hotplug core no longer allowed
407 drivers to create multiple sysfs files per physical slot (required
408 for multi-function devices, e.g.). fakephp was seen as a developer's
409 tool only, and its interface changed. Too late, we learned that
410 there were some users of the fakephp interface.
412 In 2.6.30, the original fakephp interface was restored. At the same
413 time, the PCI core gained the ability that fakephp provided, namely
414 function-level hot-remove and hot-add.
416 Since the PCI core now provides the same functionality, exposed in:
418 /sys/bus/pci/rescan
419 /sys/bus/pci/devices/.../remove
420 /sys/bus/pci/devices/.../rescan
422 there is no functional reason to maintain fakephp as well.
424 We will keep the existing module so that 'modprobe fakephp' will
425 present the old /sys/bus/pci/slots/... interface for compatibility,
426 but users are urged to migrate their applications to the API above.
428 After a reasonable transition period, we will remove the legacy
429 fakephp interface.
430 Who: Alex Chiang <achiang@hp.com>