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 ---------------------------
12 Why: prism54 FullMAC PCI / Cardbus devices used to be supported only by the
13 prism54 wireless driver. After Intersil stopped selling these
14 devices in preference for the newer more flexible SoftMAC devices
15 a SoftMAC device driver was required and prism54 did not support
16 them. The p54pci driver now exists and has been present in the kernel for
17 a while. This driver supports both SoftMAC devices and FullMAC devices.
18 The main difference between these devices was the amount of memory which
19 could be used for the firmware. The SoftMAC devices support a smaller
20 amount of memory. Because of this the SoftMAC firmware fits into FullMAC
21 devices's memory. p54pci supports not only PCI / Cardbus but also USB
22 and SPI. Since p54pci supports all devices prism54 supports
23 you will have a conflict. I'm not quite sure how distributions are
24 handling this conflict right now. prism54 was kept around due to
25 claims users may experience issues when using the SoftMAC driver.
26 Time has passed users have not reported issues. If you use prism54
27 and for whatever reason you cannot use p54pci please let us know!
28 E-mail us at: linux-wireless@vger.kernel.org
30 For more information see the p54 wiki page:
32 http://wireless.kernel.org/en/users/Drivers/p54
34 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
36 ---------------------------
38 What: IRQF_SAMPLE_RANDOM
39 Check: IRQF_SAMPLE_RANDOM
42 Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
43 sources in the kernel's current entropy model. To resolve this, every
44 input point to the kernel's entropy pool needs to better document the
45 type of entropy source it actually is. This will be replaced with
46 additional add_*_randomness functions in drivers/char/random.c
48 Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
50 ---------------------------
52 What: The ieee80211_regdom module parameter
53 When: March 2010 / desktop catchup
55 Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
56 and currently serves as an option for users to define an
57 ISO / IEC 3166 alpha2 code for the country they are currently
58 present in. Although there are userspace API replacements for this
59 through nl80211 distributions haven't yet caught up with implementing
60 decent alternatives through standard GUIs. Although available as an
61 option through iw or wpa_supplicant its just a matter of time before
62 distributions pick up good GUI options for this. The ideal solution
63 would actually consist of intelligent designs which would do this for
64 the user automatically even when travelling through different countries.
65 Until then we leave this module parameter as a compromise.
67 When userspace improves with reasonable widely-available alternatives for
68 this we will no longer need this module parameter. This entry hopes that
69 by the super-futuristically looking date of "March 2010" we will have
70 such replacements widely available.
72 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
74 ---------------------------
76 What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information
77 When: March 2010 / desktop catchup
79 Why: The old regulatory infrastructure has been replaced with a new one
80 which does not require statically defined regulatory domains. We do
81 not want to keep static regulatory domains in the kernel due to the
82 the dynamic nature of regulatory law and localization. We kept around
83 the old static definitions for the regulatory domains of:
89 and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
90 set. We will remove this option once the standard Linux desktop catches
91 up with the new userspace APIs we have implemented.
93 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
95 ---------------------------
97 What: dev->power.power_state
99 Why: Broken design for runtime control over driver power states, confusing
100 driver-internal runtime power management with: mechanisms to support
101 system-wide sleep state transitions; event codes that distinguish
102 different phases of swsusp "sleep" transitions; and userspace policy
103 inputs. This framework was never widely used, and most attempts to
104 use it were broken. Drivers should instead be exposing domain-specific
105 interfaces either to kernel or to userspace.
106 Who: Pavel Machek <pavel@suse.cz>
108 ---------------------------
110 What: Video4Linux API 1 ioctls and from Video devices.
112 Files: include/linux/videodev.h
113 Check: include/linux/videodev.h
114 Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
115 series. The old API have lots of drawbacks and don't provide enough
116 means to work with all video and audio standards. The newer API is
117 already available on the main drivers and should be used instead.
118 Newer drivers should use v4l_compat_translate_ioctl function to handle
119 old calls, replacing to newer ones.
120 Decoder iocts are using internally to allow video drivers to
121 communicate with video decoders. This should also be improved to allow
122 V4L2 calls being translated into compatible internal ioctls.
123 Compatibility ioctls will be provided, for a while, via
125 Who: Mauro Carvalho Chehab <mchehab@infradead.org>
127 ---------------------------
129 What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
131 Files: drivers/pcmcia/: pcmcia_ioctl.c
132 Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
133 normal hotpluggable bus, and with it using the default kernel
134 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
135 control ioctl needed by cardmgr and cardctl from pcmcia-cs is
136 unnecessary, and makes further cleanups and integration of the
137 PCMCIA subsystem into the Linux kernel device driver model more
138 difficult. The features provided by cardmgr and cardctl are either
139 handled by the kernel itself now or are available in the new
140 pcmciautils package available at
141 http://kernel.org/pub/linux/utils/kernel/pcmcia/
142 Who: Dominik Brodowski <linux@brodo.de>
144 ---------------------------
148 Option: CONFIG_SYSCTL_SYSCALL
149 Why: The same information is available in a more convenient from
150 /proc/sys, and none of the sysctl variables appear to be
151 important performance wise.
153 Binary sysctls are a long standing source of subtle kernel
154 bugs and security issues.
156 When I looked several months ago all I could find after
157 searching several distributions were 5 user space programs and
158 glibc (which falls back to /proc/sys) using this syscall.
160 The man page for sysctl(2) documents it as unusable for user
163 sysctl(2) is not generally ABI compatible to a 32bit user
164 space application on a 64bit and a 32bit kernel.
166 For the last several months the policy has been no new binary
167 sysctls and no one has put forward an argument to use them.
169 Binary sysctls issues seem to keep happening appearing so
170 properly deprecating them (with a warning to user space) and a
171 2 year grace warning period will mean eventually we can kill
172 them and end the pain.
174 In the mean time individual binary sysctls can be dealt with
175 in a piecewise fashion.
177 Who: Eric Biederman <ebiederm@xmission.com>
179 ---------------------------
181 What: remove EXPORT_SYMBOL(kernel_thread)
183 Files: arch/*/kernel/*_ksyms.c
185 Why: kernel_thread is a low-level implementation detail. Drivers should
186 use the <linux/kthread.h> API instead which shields them from
187 implementation details and provides a higherlevel interface that
188 prevents bugs and code duplication
189 Who: Christoph Hellwig <hch@lst.de>
191 ---------------------------
193 What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
194 (temporary transition config option provided until then)
195 The transition config option will also be removed at the same time.
197 Why: Unused symbols are both increasing the size of the kernel binary
198 and are often a sign of "wrong API"
199 Who: Arjan van de Ven <arjan@linux.intel.com>
201 ---------------------------
203 What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
205 Why: The stacking of class devices makes these values misleading and
207 Class devices should not carry any of these properties, and bus
208 devices have SUBSYTEM and DRIVER as a replacement.
209 Who: Kay Sievers <kay.sievers@suse.de>
211 ---------------------------
213 What: ACPI procfs interface
215 Why: ACPI sysfs conversion should be finished by January 2008.
216 ACPI procfs interface will be removed in July 2008 so that
217 there is enough time for the user space to catch up.
218 Who: Zhang Rui <rui.zhang@intel.com>
220 ---------------------------
222 What: /proc/acpi/button
224 Why: /proc/acpi/button has been replaced by events to the input layer
226 Who: Len Brown <len.brown@intel.com>
228 ---------------------------
230 What: /proc/acpi/event
232 Why: /proc/acpi/event has been replaced by events via the input layer
233 and netlink since 2.6.23.
234 Who: Len Brown <len.brown@intel.com>
236 ---------------------------
238 What: i386/x86_64 bzImage symlinks
241 Why: The i386/x86_64 merge provides a symlink to the old bzImage
242 location so not yet updated user space tools, e.g. package
243 scripts, do not break.
244 Who: Thomas Gleixner <tglx@linutronix.de>
246 ---------------------------
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
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: /sys/o2cb symlink
281 Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
282 exists as a symlink for backwards compatibility for old versions of
283 ocfs2-tools. 2 years should be sufficient time to phase in new versions
284 which know to look in /sys/fs/o2cb.
285 Who: ocfs2-devel@oss.oracle.com
287 ---------------------------
289 What: Ability for non root users to shm_get hugetlb pages based on mlock
292 Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
293 have CAP_IPC_LOCK to be able to allocate shm segments backed by
294 huge pages. The mlock based rlimit check to allow shm hugetlb is
295 inconsistent with mmap based allocations. Hence it is being
297 Who: Ravikiran Thirumalai <kiran@scalex86.org>
299 ---------------------------
301 What: CONFIG_THERMAL_HWMON
303 Why: This option was introduced just to allow older lm-sensors userspace
304 to keep working over the upgrade to 2.6.26. At the scheduled time of
305 removal fixed lm-sensors (2.x or 3.x) should be readily available.
306 Who: Rene Herman <rene.herman@gmail.com>
308 ---------------------------
310 What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
311 (in net/core/net-sysfs.c)
312 When: After the only user (hal) has seen a release with the patches
313 for enough time, probably some time in 2010.
314 Why: Over 1K .text/.data size reduction, data is available in other
316 Who: Johannes Berg <johannes@sipsolutions.net>
318 ---------------------------
320 What: CONFIG_NF_CT_ACCT
322 Why: Accounting can now be enabled/disabled without kernel recompilation.
323 Currently used only to set a default value for a feature that is also
324 controlled by a kernel/module/sysfs/sysctl parameter.
325 Who: Krzysztof Piotr Oledzki <ole@ans.pl>
327 ---------------------------
329 What: sysfs ui for changing p4-clockmod parameters
331 Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
332 e088e4c9cdb618675874becb91b2fd581ee707e6.
333 Removal is subject to fixing any remaining bugs in ACPI which may
334 cause the thermal throttling not to happen at the right time.
335 Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
337 -----------------------------
339 What: __do_IRQ all in one fits nothing interrupt handler
341 Why: __do_IRQ was kept for easy migration to the type flow handlers.
342 More than two years of migration time is enough.
343 Who: Thomas Gleixner <tglx@linutronix.de>
345 -----------------------------
347 What: fakephp and associated sysfs files in /sys/bus/pci/slots/
349 Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
350 represent a machine's physical PCI slots. The change in semantics
351 had userspace implications, as the hotplug core no longer allowed
352 drivers to create multiple sysfs files per physical slot (required
353 for multi-function devices, e.g.). fakephp was seen as a developer's
354 tool only, and its interface changed. Too late, we learned that
355 there were some users of the fakephp interface.
357 In 2.6.30, the original fakephp interface was restored. At the same
358 time, the PCI core gained the ability that fakephp provided, namely
359 function-level hot-remove and hot-add.
361 Since the PCI core now provides the same functionality, exposed in:
364 /sys/bus/pci/devices/.../remove
365 /sys/bus/pci/devices/.../rescan
367 there is no functional reason to maintain fakephp as well.
369 We will keep the existing module so that 'modprobe fakephp' will
370 present the old /sys/bus/pci/slots/... interface for compatibility,
371 but users are urged to migrate their applications to the API above.
373 After a reasonable transition period, we will remove the legacy
375 Who: Alex Chiang <achiang@hp.com>
377 ---------------------------
379 What: CONFIG_RFKILL_INPUT
381 Why: Should be implemented in userspace, policy daemon.
382 Who: Johannes Berg <johannes@sipsolutions.net>
384 ---------------------------
388 Why: last user (audit) will be converted to the newer more generic
389 and more easily maintained fsnotify subsystem
390 Who: Eric Paris <eparis@redhat.com>
392 ----------------------------
394 What: lock_policy_rwsem_* and unlock_policy_rwsem_* will not be
395 exported interface anymore.
397 Why: cpu_policy_rwsem has a new cleaner definition making it local to
398 cpufreq core and contained inside cpufreq.c. Other dependent
399 drivers should not use it in order to safely avoid lockdep issues.
400 Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
402 ----------------------------
404 What: sound-slot/service-* module aliases and related clutters in
407 Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
408 (14) and requests modules using custom sound-slot/service-*
409 module aliases. The only benefit of doing this is allowing
410 use of custom module aliases which might as well be considered
411 a bug at this point. This preemptive claiming prevents
412 alternative OSS implementations.
414 Till the feature is removed, the kernel will be requesting
415 both sound-slot/service-* and the standard char-major-* module
416 aliases and allow turning off the pre-claiming selectively via
417 CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
420 After the transition phase is complete, both the custom module
421 aliases and switches to disable it will go away. This removal
422 will also allow making ALSA OSS emulation independent of
423 sound_core. The dependency will be broken then too.
424 Who: Tejun Heo <tj@kernel.org>
426 ----------------------------
428 What: Support for VMware's guest paravirtuliazation technique [VMI] will be
430 When: 2.6.37 or earlier.
431 Why: With the recent innovations in CPU hardware acceleration technologies
432 from Intel and AMD, VMware ran a few experiments to compare these
433 techniques to guest paravirtualization technique on VMware's platform.
434 These hardware assisted virtualization techniques have outperformed the
435 performance benefits provided by VMI in most of the workloads. VMware
436 expects that these hardware features will be ubiquitous in a couple of
437 years, as a result, VMware has started a phased retirement of this
438 feature from the hypervisor. We will be removing this feature from the
439 Kernel too. Right now we are targeting 2.6.37 but can retire earlier if
440 technical reasons (read opportunity to remove major chunk of pvops)
443 Please note that VMI has always been an optimization and non-VMI kernels
444 still work fine on VMware's platform.
445 Latest versions of VMware's product which support VMI are,
446 Workstation 7.0 and VSphere 4.0 on ESX side, future maintainence
447 releases for these products will continue supporting VMI.
449 For more details about VMI retirement take a look at this,
450 http://blogs.vmware.com/guestosguide/2009/09/vmi-retirement.html
452 Who: Alok N Kataria <akataria@vmware.com>
454 ----------------------------
456 What: adt7473 hardware monitoring driver
458 Why: Obsoleted by the adt7475 driver.
459 Who: Jean Delvare <khali@linux-fr.org>
461 ---------------------------
462 What: Support for lcd_switch and display_get in asus-laptop driver
464 Why: These two features use non-standard interfaces. There are the
465 only features that really need multiple path to guess what's
466 the right method name on a specific laptop.
468 Removing them will allow to remove a lot of code an significantly
471 This will affect the backlight code which won't be able to know
472 if the backlight is on or off. The platform display file will also be
473 write only (like the one in eeepc-laptop).
475 This should'nt affect a lot of user because they usually know
476 when their display is on or off.
478 Who: Corentin Chary <corentin.chary@gmail.com>
480 ----------------------------
482 What: usbvideo quickcam_messenger driver
484 Files: drivers/media/video/usbvideo/quickcam_messenger.[ch]
485 Why: obsolete v4l1 driver replaced by gspca_stv06xx
486 Who: Hans de Goede <hdegoede@redhat.com>
488 ----------------------------
490 What: ov511 v4l1 driver
492 Files: drivers/media/video/ov511.[ch]
493 Why: obsolete v4l1 driver replaced by gspca_ov519
494 Who: Hans de Goede <hdegoede@redhat.com>
496 ----------------------------
498 What: w9968cf v4l1 driver
500 Files: drivers/media/video/w9968cf*.[ch]
501 Why: obsolete v4l1 driver replaced by gspca_ov519
502 Who: Hans de Goede <hdegoede@redhat.com>
504 ----------------------------
506 What: ovcamchip sensor framework
508 Files: drivers/media/video/ovcamchip/*
509 Why: Only used by obsoleted v4l1 drivers
510 Who: Hans de Goede <hdegoede@redhat.com>
512 ----------------------------
514 What: stv680 v4l1 driver
516 Files: drivers/media/video/stv680.[ch]
517 Why: obsolete v4l1 driver replaced by gspca_stv0680
518 Who: Hans de Goede <hdegoede@redhat.com>
520 ----------------------------
522 What: zc0301 v4l driver
524 Files: drivers/media/video/zc0301/*
525 Why: Duplicate functionality with the gspca_zc3xx driver, zc0301 only
526 supports 2 USB-ID's (because it only supports a limited set of
527 sensors) wich are also supported by the gspca_zc3xx driver
528 (which supports 53 USB-ID's in total)
529 Who: Hans de Goede <hdegoede@redhat.com>