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: Deprecated snapshot ioctls
55 Why: The ioctls in kernel/power/user.c were marked as deprecated long time
56 ago. Now they notify users about that so that they need to replace
57 their userspace. After some more time, remove them completely.
59 Who: Jiri Slaby <jirislaby@gmail.com>
61 ---------------------------
63 What: The ieee80211_regdom module parameter
64 When: March 2010 / desktop catchup
66 Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
67 and currently serves as an option for users to define an
68 ISO / IEC 3166 alpha2 code for the country they are currently
69 present in. Although there are userspace API replacements for this
70 through nl80211 distributions haven't yet caught up with implementing
71 decent alternatives through standard GUIs. Although available as an
72 option through iw or wpa_supplicant its just a matter of time before
73 distributions pick up good GUI options for this. The ideal solution
74 would actually consist of intelligent designs which would do this for
75 the user automatically even when travelling through different countries.
76 Until then we leave this module parameter as a compromise.
78 When userspace improves with reasonable widely-available alternatives for
79 this we will no longer need this module parameter. This entry hopes that
80 by the super-futuristically looking date of "March 2010" we will have
81 such replacements widely available.
83 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
85 ---------------------------
87 What: dev->power.power_state
89 Why: Broken design for runtime control over driver power states, confusing
90 driver-internal runtime power management with: mechanisms to support
91 system-wide sleep state transitions; event codes that distinguish
92 different phases of swsusp "sleep" transitions; and userspace policy
93 inputs. This framework was never widely used, and most attempts to
94 use it were broken. Drivers should instead be exposing domain-specific
95 interfaces either to kernel or to userspace.
96 Who: Pavel Machek <pavel@suse.cz>
98 ---------------------------
100 What: Video4Linux API 1 ioctls and from Video devices.
102 Files: include/linux/videodev.h
103 Check: include/linux/videodev.h
104 Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
105 series. The old API have lots of drawbacks and don't provide enough
106 means to work with all video and audio standards. The newer API is
107 already available on the main drivers and should be used instead.
108 Newer drivers should use v4l_compat_translate_ioctl function to handle
109 old calls, replacing to newer ones.
110 Decoder iocts are using internally to allow video drivers to
111 communicate with video decoders. This should also be improved to allow
112 V4L2 calls being translated into compatible internal ioctls.
113 Compatibility ioctls will be provided, for a while, via
115 Who: Mauro Carvalho Chehab <mchehab@infradead.org>
117 ---------------------------
119 What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
121 Files: drivers/pcmcia/: pcmcia_ioctl.c
122 Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
123 normal hotpluggable bus, and with it using the default kernel
124 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
125 control ioctl needed by cardmgr and cardctl from pcmcia-cs is
126 unnecessary, and makes further cleanups and integration of the
127 PCMCIA subsystem into the Linux kernel device driver model more
128 difficult. The features provided by cardmgr and cardctl are either
129 handled by the kernel itself now or are available in the new
130 pcmciautils package available at
131 http://kernel.org/pub/linux/utils/kernel/pcmcia/
132 Who: Dominik Brodowski <linux@brodo.de>
134 ---------------------------
138 Option: CONFIG_SYSCTL_SYSCALL
139 Why: The same information is available in a more convenient from
140 /proc/sys, and none of the sysctl variables appear to be
141 important performance wise.
143 Binary sysctls are a long standing source of subtle kernel
144 bugs and security issues.
146 When I looked several months ago all I could find after
147 searching several distributions were 5 user space programs and
148 glibc (which falls back to /proc/sys) using this syscall.
150 The man page for sysctl(2) documents it as unusable for user
153 sysctl(2) is not generally ABI compatible to a 32bit user
154 space application on a 64bit and a 32bit kernel.
156 For the last several months the policy has been no new binary
157 sysctls and no one has put forward an argument to use them.
159 Binary sysctls issues seem to keep happening appearing so
160 properly deprecating them (with a warning to user space) and a
161 2 year grace warning period will mean eventually we can kill
162 them and end the pain.
164 In the mean time individual binary sysctls can be dealt with
165 in a piecewise fashion.
167 Who: Eric Biederman <ebiederm@xmission.com>
169 ---------------------------
171 What: remove EXPORT_SYMBOL(kernel_thread)
173 Files: arch/*/kernel/*_ksyms.c
175 Why: kernel_thread is a low-level implementation detail. Drivers should
176 use the <linux/kthread.h> API instead which shields them from
177 implementation details and provides a higherlevel interface that
178 prevents bugs and code duplication
179 Who: Christoph Hellwig <hch@lst.de>
181 ---------------------------
183 What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
184 (temporary transition config option provided until then)
185 The transition config option will also be removed at the same time.
187 Why: Unused symbols are both increasing the size of the kernel binary
188 and are often a sign of "wrong API"
189 Who: Arjan van de Ven <arjan@linux.intel.com>
191 ---------------------------
193 What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
195 Why: The stacking of class devices makes these values misleading and
197 Class devices should not carry any of these properties, and bus
198 devices have SUBSYTEM and DRIVER as a replacement.
199 Who: Kay Sievers <kay.sievers@suse.de>
201 ---------------------------
203 What: ACPI procfs interface
205 Why: ACPI sysfs conversion should be finished by January 2008.
206 ACPI procfs interface will be removed in July 2008 so that
207 there is enough time for the user space to catch up.
208 Who: Zhang Rui <rui.zhang@intel.com>
210 ---------------------------
212 What: /proc/acpi/button
214 Why: /proc/acpi/button has been replaced by events to the input layer
216 Who: Len Brown <len.brown@intel.com>
218 ---------------------------
220 What: /proc/acpi/event
222 Why: /proc/acpi/event has been replaced by events via the input layer
223 and netlink since 2.6.23.
224 Who: Len Brown <len.brown@intel.com>
226 ---------------------------
228 What: i386/x86_64 bzImage symlinks
231 Why: The i386/x86_64 merge provides a symlink to the old bzImage
232 location so not yet updated user space tools, e.g. package
233 scripts, do not break.
234 Who: Thomas Gleixner <tglx@linutronix.de>
236 ---------------------------
239 - xt_recent: the old ipt_recent proc dir
240 (superseded by /proc/net/xt_recent)
242 When: January 2009 or Linux 2.7.0, whichever comes first
243 Why: Superseded by newer revisions or modules
244 Who: Jan Engelhardt <jengelh@computergmbh.de>
246 ---------------------------
248 What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
250 Why: All callers should use explicit gpio_request()/gpio_free().
251 The autorequest mechanism in gpiolib was provided mostly as a
252 migration aid for legacy GPIO interfaces (for SOC based GPIOs).
253 Those users have now largely migrated. Platforms implementing
254 the GPIO interfaces without using gpiolib will see no changes.
255 Who: David Brownell <dbrownell@users.sourceforge.net>
256 ---------------------------
258 What: b43 support for firmware revision < 410
259 When: The schedule was July 2008, but it was decided that we are going to keep the
260 code as long as there are no major maintanance headaches.
261 So it _could_ be removed _any_ time now, if it conflicts with something new.
262 Why: The support code for the old firmware hurts code readability/maintainability
263 and slightly hurts runtime performance. Bugfixes for the old firmware
264 are not provided by Broadcom anymore.
265 Who: Michael Buesch <mb@bu3sch.de>
267 ---------------------------
269 What: /sys/o2cb symlink
271 Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
272 exists as a symlink for backwards compatibility for old versions of
273 ocfs2-tools. 2 years should be sufficient time to phase in new versions
274 which know to look in /sys/fs/o2cb.
275 Who: ocfs2-devel@oss.oracle.com
277 ---------------------------
279 What: Ability for non root users to shm_get hugetlb pages based on mlock
282 Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
283 have CAP_IPC_LOCK to be able to allocate shm segments backed by
284 huge pages. The mlock based rlimit check to allow shm hugetlb is
285 inconsistent with mmap based allocations. Hence it is being
287 Who: Ravikiran Thirumalai <kiran@scalex86.org>
289 ---------------------------
291 What: CONFIG_THERMAL_HWMON
293 Why: This option was introduced just to allow older lm-sensors userspace
294 to keep working over the upgrade to 2.6.26. At the scheduled time of
295 removal fixed lm-sensors (2.x or 3.x) should be readily available.
296 Who: Rene Herman <rene.herman@gmail.com>
298 ---------------------------
300 What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
301 (in net/core/net-sysfs.c)
302 When: After the only user (hal) has seen a release with the patches
303 for enough time, probably some time in 2010.
304 Why: Over 1K .text/.data size reduction, data is available in other
306 Who: Johannes Berg <johannes@sipsolutions.net>
308 ---------------------------
310 What: CONFIG_NF_CT_ACCT
312 Why: Accounting can now be enabled/disabled without kernel recompilation.
313 Currently used only to set a default value for a feature that is also
314 controlled by a kernel/module/sysfs/sysctl parameter.
315 Who: Krzysztof Piotr Oledzki <ole@ans.pl>
317 ---------------------------
319 What: sysfs ui for changing p4-clockmod parameters
321 Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
322 e088e4c9cdb618675874becb91b2fd581ee707e6.
323 Removal is subject to fixing any remaining bugs in ACPI which may
324 cause the thermal throttling not to happen at the right time.
325 Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
327 -----------------------------
329 What: __do_IRQ all in one fits nothing interrupt handler
331 Why: __do_IRQ was kept for easy migration to the type flow handlers.
332 More than two years of migration time is enough.
333 Who: Thomas Gleixner <tglx@linutronix.de>
335 -----------------------------
337 What: fakephp and associated sysfs files in /sys/bus/pci/slots/
339 Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
340 represent a machine's physical PCI slots. The change in semantics
341 had userspace implications, as the hotplug core no longer allowed
342 drivers to create multiple sysfs files per physical slot (required
343 for multi-function devices, e.g.). fakephp was seen as a developer's
344 tool only, and its interface changed. Too late, we learned that
345 there were some users of the fakephp interface.
347 In 2.6.30, the original fakephp interface was restored. At the same
348 time, the PCI core gained the ability that fakephp provided, namely
349 function-level hot-remove and hot-add.
351 Since the PCI core now provides the same functionality, exposed in:
354 /sys/bus/pci/devices/.../remove
355 /sys/bus/pci/devices/.../rescan
357 there is no functional reason to maintain fakephp as well.
359 We will keep the existing module so that 'modprobe fakephp' will
360 present the old /sys/bus/pci/slots/... interface for compatibility,
361 but users are urged to migrate their applications to the API above.
363 After a reasonable transition period, we will remove the legacy
365 Who: Alex Chiang <achiang@hp.com>
367 ---------------------------
369 What: CONFIG_RFKILL_INPUT
371 Why: Should be implemented in userspace, policy daemon.
372 Who: Johannes Berg <johannes@sipsolutions.net>
374 ---------------------------
378 Why: last user (audit) will be converted to the newer more generic
379 and more easily maintained fsnotify subsystem
380 Who: Eric Paris <eparis@redhat.com>
382 ----------------------------
384 What: lock_policy_rwsem_* and unlock_policy_rwsem_* will not be
385 exported interface anymore.
387 Why: cpu_policy_rwsem has a new cleaner definition making it local to
388 cpufreq core and contained inside cpufreq.c. Other dependent
389 drivers should not use it in order to safely avoid lockdep issues.
390 Who: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
392 ----------------------------
394 What: sound-slot/service-* module aliases and related clutters in
397 Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
398 (14) and requests modules using custom sound-slot/service-*
399 module aliases. The only benefit of doing this is allowing
400 use of custom module aliases which might as well be considered
401 a bug at this point. This preemptive claiming prevents
402 alternative OSS implementations.
404 Till the feature is removed, the kernel will be requesting
405 both sound-slot/service-* and the standard char-major-* module
406 aliases and allow turning off the pre-claiming selectively via
407 CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
410 After the transition phase is complete, both the custom module
411 aliases and switches to disable it will go away. This removal
412 will also allow making ALSA OSS emulation independent of
413 sound_core. The dependency will be broken then too.
414 Who: Tejun Heo <tj@kernel.org>
416 ----------------------------
418 What: Support for VMware's guest paravirtuliazation technique [VMI] will be
420 When: 2.6.37 or earlier.
421 Why: With the recent innovations in CPU hardware acceleration technologies
422 from Intel and AMD, VMware ran a few experiments to compare these
423 techniques to guest paravirtualization technique on VMware's platform.
424 These hardware assisted virtualization techniques have outperformed the
425 performance benefits provided by VMI in most of the workloads. VMware
426 expects that these hardware features will be ubiquitous in a couple of
427 years, as a result, VMware has started a phased retirement of this
428 feature from the hypervisor. We will be removing this feature from the
429 Kernel too. Right now we are targeting 2.6.37 but can retire earlier if
430 technical reasons (read opportunity to remove major chunk of pvops)
433 Please note that VMI has always been an optimization and non-VMI kernels
434 still work fine on VMware's platform.
435 Latest versions of VMware's product which support VMI are,
436 Workstation 7.0 and VSphere 4.0 on ESX side, future maintainence
437 releases for these products will continue supporting VMI.
439 For more details about VMI retirement take a look at this,
440 http://blogs.vmware.com/guestosguide/2009/09/vmi-retirement.html
442 Who: Alok N Kataria <akataria@vmware.com>
444 ----------------------------
446 What: adt7473 hardware monitoring driver
448 Why: Obsoleted by the adt7475 driver.
449 Who: Jean Delvare <khali@linux-fr.org>
451 ---------------------------
452 What: Support for lcd_switch and display_get in asus-laptop driver
454 Why: These two features use non-standard interfaces. There are the
455 only features that really need multiple path to guess what's
456 the right method name on a specific laptop.
458 Removing them will allow to remove a lot of code an significantly
461 This will affect the backlight code which won't be able to know
462 if the backlight is on or off. The platform display file will also be
463 write only (like the one in eeepc-laptop).
465 This should'nt affect a lot of user because they usually know
466 when their display is on or off.
468 Who: Corentin Chary <corentin.chary@gmail.com>
470 ----------------------------
472 What: usbvideo quickcam_messenger driver
474 Files: drivers/media/video/usbvideo/quickcam_messenger.[ch]
475 Why: obsolete v4l1 driver replaced by gspca_stv06xx
476 Who: Hans de Goede <hdegoede@redhat.com>
478 ----------------------------
480 What: ov511 v4l1 driver
482 Files: drivers/media/video/ov511.[ch]
483 Why: obsolete v4l1 driver replaced by gspca_ov519
484 Who: Hans de Goede <hdegoede@redhat.com>
486 ----------------------------
488 What: w9968cf v4l1 driver
490 Files: drivers/media/video/w9968cf*.[ch]
491 Why: obsolete v4l1 driver replaced by gspca_ov519
492 Who: Hans de Goede <hdegoede@redhat.com>
494 ----------------------------
496 What: ovcamchip sensor framework
498 Files: drivers/media/video/ovcamchip/*
499 Why: Only used by obsoleted v4l1 drivers
500 Who: Hans de Goede <hdegoede@redhat.com>
502 ----------------------------
504 What: stv680 v4l1 driver
506 Files: drivers/media/video/stv680.[ch]
507 Why: obsolete v4l1 driver replaced by gspca_stv0680
508 Who: Hans de Goede <hdegoede@redhat.com>
510 ----------------------------
512 What: zc0301 v4l driver
514 Files: drivers/media/video/zc0301/*
515 Why: Duplicate functionality with the gspca_zc3xx driver, zc0301 only
516 supports 2 USB-ID's (because it only supports a limited set of
517 sensors) wich are also supported by the gspca_zc3xx driver
518 (which supports 53 USB-ID's in total)
519 Who: Hans de Goede <hdegoede@redhat.com>
521 ----------------------------
523 What: sysfs-class-rfkill state file
525 Files: net/rfkill/core.c
526 Why: Documented as obsolete since Feb 2010. This file is limited to 3
527 states while the rfkill drivers can have 4 states.
528 Who: anybody or Florian Mickler <florian@mickler.org>
530 ----------------------------
532 What: sysfs-class-rfkill claim file
534 Files: net/rfkill/core.c
535 Why: It is not possible to claim an rfkill driver since 2007. This is
536 Documented as obsolete since Feb 2010.
537 Who: anybody or Florian Mickler <florian@mickler.org>
539 ----------------------------
543 Files: drivers/isdn/capi/capifs.*
544 Why: udev fully replaces this special file system that only contains CAPI
545 NCCI TTY device nodes. User space (pppdcapiplugin) works without
546 noticing the difference.
547 Who: Jan Kiszka <jan.kiszka@web.de>