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: x86 floppy disable_hlt
11 Why: ancient workaround of dubious utility clutters the
12 code used by everybody else.
13 Who: Len Brown <len.brown@intel.com>
15 ---------------------------
17 What: CONFIG_APM_CPU_IDLE, and its ability to call APM BIOS in idle
19 Why: This optional sub-feature of APM is of dubious reliability,
20 and ancient APM laptops are likely better served by calling HLT.
21 Deleting CONFIG_APM_CPU_IDLE allows x86 to stop exporting
22 the pm_idle function pointer to modules.
23 Who: Len Brown <len.brown@intel.com>
25 ----------------------------
27 What: x86_32 "no-hlt" cmdline param
29 Why: remove a branch from idle path, simplify code used by everybody.
30 This option disabled the use of HLT in idle and machine_halt()
31 for hardware that was flakey 15-years ago. Today we have
32 "idle=poll" that removed HLT from idle, and so if such a machine
33 is still running the upstream kernel, "idle=poll" is likely sufficient.
34 Who: Len Brown <len.brown@intel.com>
36 ----------------------------
38 What: x86 "idle=mwait" cmdline param
40 Why: simplify x86 idle code
41 Who: Len Brown <len.brown@intel.com>
43 ----------------------------
48 Why: prism54 FullMAC PCI / Cardbus devices used to be supported only by the
49 prism54 wireless driver. After Intersil stopped selling these
50 devices in preference for the newer more flexible SoftMAC devices
51 a SoftMAC device driver was required and prism54 did not support
52 them. The p54pci driver now exists and has been present in the kernel for
53 a while. This driver supports both SoftMAC devices and FullMAC devices.
54 The main difference between these devices was the amount of memory which
55 could be used for the firmware. The SoftMAC devices support a smaller
56 amount of memory. Because of this the SoftMAC firmware fits into FullMAC
57 devices's memory. p54pci supports not only PCI / Cardbus but also USB
58 and SPI. Since p54pci supports all devices prism54 supports
59 you will have a conflict. I'm not quite sure how distributions are
60 handling this conflict right now. prism54 was kept around due to
61 claims users may experience issues when using the SoftMAC driver.
62 Time has passed users have not reported issues. If you use prism54
63 and for whatever reason you cannot use p54pci please let us know!
64 E-mail us at: linux-wireless@vger.kernel.org
66 For more information see the p54 wiki page:
68 http://wireless.kernel.org/en/users/Drivers/p54
70 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
72 ---------------------------
74 What: IRQF_SAMPLE_RANDOM
75 Check: IRQF_SAMPLE_RANDOM
78 Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
79 sources in the kernel's current entropy model. To resolve this, every
80 input point to the kernel's entropy pool needs to better document the
81 type of entropy source it actually is. This will be replaced with
82 additional add_*_randomness functions in drivers/char/random.c
84 Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
86 ---------------------------
88 What: The ieee80211_regdom module parameter
89 When: March 2010 / desktop catchup
91 Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
92 and currently serves as an option for users to define an
93 ISO / IEC 3166 alpha2 code for the country they are currently
94 present in. Although there are userspace API replacements for this
95 through nl80211 distributions haven't yet caught up with implementing
96 decent alternatives through standard GUIs. Although available as an
97 option through iw or wpa_supplicant its just a matter of time before
98 distributions pick up good GUI options for this. The ideal solution
99 would actually consist of intelligent designs which would do this for
100 the user automatically even when travelling through different countries.
101 Until then we leave this module parameter as a compromise.
103 When userspace improves with reasonable widely-available alternatives for
104 this we will no longer need this module parameter. This entry hopes that
105 by the super-futuristically looking date of "March 2010" we will have
106 such replacements widely available.
108 Who: Luis R. Rodriguez <lrodriguez@atheros.com>
110 ---------------------------
112 What: dev->power.power_state
114 Why: Broken design for runtime control over driver power states, confusing
115 driver-internal runtime power management with: mechanisms to support
116 system-wide sleep state transitions; event codes that distinguish
117 different phases of swsusp "sleep" transitions; and userspace policy
118 inputs. This framework was never widely used, and most attempts to
119 use it were broken. Drivers should instead be exposing domain-specific
120 interfaces either to kernel or to userspace.
121 Who: Pavel Machek <pavel@ucw.cz>
123 ---------------------------
125 What: /proc/<pid>/oom_adj
127 Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
128 badness heuristic used to determine which task to kill when the kernel
131 The badness heuristic has since been rewritten since the introduction of
132 this tunable such that its meaning is deprecated. The value was
133 implemented as a bitshift on a score generated by the badness()
134 function that did not have any precise units of measure. With the
135 rewrite, the score is given as a proportion of available memory to the
136 task allocating pages, so using a bitshift which grows the score
137 exponentially is, thus, impossible to tune with fine granularity.
139 A much more powerful interface, /proc/<pid>/oom_score_adj, was
140 introduced with the oom killer rewrite that allows users to increase or
141 decrease the badness score linearly. This interface will replace
144 A warning will be emitted to the kernel log if an application uses this
145 deprecated interface. After it is printed once, future warnings will be
146 suppressed until the kernel is rebooted.
148 ---------------------------
150 What: remove EXPORT_SYMBOL(kernel_thread)
152 Files: arch/*/kernel/*_ksyms.c
154 Why: kernel_thread is a low-level implementation detail. Drivers should
155 use the <linux/kthread.h> API instead which shields them from
156 implementation details and provides a higherlevel interface that
157 prevents bugs and code duplication
158 Who: Christoph Hellwig <hch@lst.de>
160 ---------------------------
162 What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
163 (temporary transition config option provided until then)
164 The transition config option will also be removed at the same time.
166 Why: Unused symbols are both increasing the size of the kernel binary
167 and are often a sign of "wrong API"
168 Who: Arjan van de Ven <arjan@linux.intel.com>
170 ---------------------------
172 What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
174 Why: The stacking of class devices makes these values misleading and
176 Class devices should not carry any of these properties, and bus
177 devices have SUBSYTEM and DRIVER as a replacement.
178 Who: Kay Sievers <kay.sievers@suse.de>
180 ---------------------------
182 What: ACPI procfs interface
184 Why: ACPI sysfs conversion should be finished by January 2008.
185 ACPI procfs interface will be removed in July 2008 so that
186 there is enough time for the user space to catch up.
187 Who: Zhang Rui <rui.zhang@intel.com>
189 ---------------------------
191 What: CONFIG_ACPI_PROCFS_POWER
193 Why: sysfs I/F for ACPI power devices, including AC and Battery,
194 has been working in upstream kernel since 2.6.24, Sep 2007.
195 In 2.6.37, we make the sysfs I/F always built in and this option
197 Remove this option and the ACPI power procfs interface in 2.6.39.
198 Who: Zhang Rui <rui.zhang@intel.com>
200 ---------------------------
202 What: /proc/acpi/event
204 Why: /proc/acpi/event has been replaced by events via the input layer
205 and netlink since 2.6.23.
206 Who: Len Brown <len.brown@intel.com>
208 ---------------------------
210 What: i386/x86_64 bzImage symlinks
213 Why: The i386/x86_64 merge provides a symlink to the old bzImage
214 location so not yet updated user space tools, e.g. package
215 scripts, do not break.
216 Who: Thomas Gleixner <tglx@linutronix.de>
218 ---------------------------
220 What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
222 Why: All callers should use explicit gpio_request()/gpio_free().
223 The autorequest mechanism in gpiolib was provided mostly as a
224 migration aid for legacy GPIO interfaces (for SOC based GPIOs).
225 Those users have now largely migrated. Platforms implementing
226 the GPIO interfaces without using gpiolib will see no changes.
227 Who: David Brownell <dbrownell@users.sourceforge.net>
228 ---------------------------
230 What: b43 support for firmware revision < 410
231 When: The schedule was July 2008, but it was decided that we are going to keep the
232 code as long as there are no major maintanance headaches.
233 So it _could_ be removed _any_ time now, if it conflicts with something new.
234 Why: The support code for the old firmware hurts code readability/maintainability
235 and slightly hurts runtime performance. Bugfixes for the old firmware
236 are not provided by Broadcom anymore.
237 Who: Michael Buesch <m@bues.ch>
239 ---------------------------
241 What: Ability for non root users to shm_get hugetlb pages based on mlock
244 Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
245 have CAP_IPC_LOCK to be able to allocate shm segments backed by
246 huge pages. The mlock based rlimit check to allow shm hugetlb is
247 inconsistent with mmap based allocations. Hence it is being
249 Who: Ravikiran Thirumalai <kiran@scalex86.org>
251 ---------------------------
253 What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
254 (in net/core/net-sysfs.c)
255 When: After the only user (hal) has seen a release with the patches
256 for enough time, probably some time in 2010.
257 Why: Over 1K .text/.data size reduction, data is available in other
259 Who: Johannes Berg <johannes@sipsolutions.net>
261 ---------------------------
263 What: sysfs ui for changing p4-clockmod parameters
265 Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
266 e088e4c9cdb618675874becb91b2fd581ee707e6.
267 Removal is subject to fixing any remaining bugs in ACPI which may
268 cause the thermal throttling not to happen at the right time.
269 Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
271 -----------------------------
273 What: fakephp and associated sysfs files in /sys/bus/pci/slots/
275 Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
276 represent a machine's physical PCI slots. The change in semantics
277 had userspace implications, as the hotplug core no longer allowed
278 drivers to create multiple sysfs files per physical slot (required
279 for multi-function devices, e.g.). fakephp was seen as a developer's
280 tool only, and its interface changed. Too late, we learned that
281 there were some users of the fakephp interface.
283 In 2.6.30, the original fakephp interface was restored. At the same
284 time, the PCI core gained the ability that fakephp provided, namely
285 function-level hot-remove and hot-add.
287 Since the PCI core now provides the same functionality, exposed in:
290 /sys/bus/pci/devices/.../remove
291 /sys/bus/pci/devices/.../rescan
293 there is no functional reason to maintain fakephp as well.
295 We will keep the existing module so that 'modprobe fakephp' will
296 present the old /sys/bus/pci/slots/... interface for compatibility,
297 but users are urged to migrate their applications to the API above.
299 After a reasonable transition period, we will remove the legacy
301 Who: Alex Chiang <achiang@hp.com>
303 ---------------------------
305 What: CONFIG_RFKILL_INPUT
307 Why: Should be implemented in userspace, policy daemon.
308 Who: Johannes Berg <johannes@sipsolutions.net>
310 ----------------------------
312 What: sound-slot/service-* module aliases and related clutters in
315 Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
316 (14) and requests modules using custom sound-slot/service-*
317 module aliases. The only benefit of doing this is allowing
318 use of custom module aliases which might as well be considered
319 a bug at this point. This preemptive claiming prevents
320 alternative OSS implementations.
322 Till the feature is removed, the kernel will be requesting
323 both sound-slot/service-* and the standard char-major-* module
324 aliases and allow turning off the pre-claiming selectively via
325 CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
328 After the transition phase is complete, both the custom module
329 aliases and switches to disable it will go away. This removal
330 will also allow making ALSA OSS emulation independent of
331 sound_core. The dependency will be broken then too.
332 Who: Tejun Heo <tj@kernel.org>
334 ----------------------------
336 What: sysfs-class-rfkill state file
338 Files: net/rfkill/core.c
339 Why: Documented as obsolete since Feb 2010. This file is limited to 3
340 states while the rfkill drivers can have 4 states.
341 Who: anybody or Florian Mickler <florian@mickler.org>
343 ----------------------------
345 What: sysfs-class-rfkill claim file
347 Files: net/rfkill/core.c
348 Why: It is not possible to claim an rfkill driver since 2007. This is
349 Documented as obsolete since Feb 2010.
350 Who: anybody or Florian Mickler <florian@mickler.org>
352 ----------------------------
354 What: KVM paravirt mmu host support
356 Why: The paravirt mmu host support is slower than non-paravirt mmu, both
357 on newer and older hardware. It is already not exposed to the guest,
358 and kept only for live migration purposes.
359 Who: Avi Kivity <avi@redhat.com>
361 ----------------------------
363 What: iwlwifi 50XX module parameters
365 Why: The "..50" modules parameters were used to configure 5000 series and
366 up devices; different set of module parameters also available for 4965
367 with same functionalities. Consolidate both set into single place
368 in drivers/net/wireless/iwlwifi/iwl-agn.c
370 Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
372 ----------------------------
374 What: iwl4965 alias support
376 Why: Internal alias support has been present in module-init-tools for some
377 time, the MODULE_ALIAS("iwl4965") boilerplate aliases can be removed
380 Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
382 ---------------------------
385 Files: net/netfilter/xt_NOTRACK.c
387 Why: Superseded by xt_CT
388 Who: Netfilter developer team <netfilter-devel@vger.kernel.org>
390 ----------------------------
394 Why: The flag is a NOOP as we run interrupt handlers with interrupts disabled
395 Who: Thomas Gleixner <tglx@linutronix.de>
397 ----------------------------
399 What: PCI DMA unmap state API
401 Why: PCI DMA unmap state API (include/linux/pci-dma.h) was replaced
402 with DMA unmap state API (DMA unmap state API can be used for
404 Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
406 ----------------------------
408 What: iwlwifi disable_hw_scan module parameters
410 Why: Hareware scan is the prefer method for iwlwifi devices for
411 scanning operation. Remove software scan support for all the
414 Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
416 ----------------------------
418 What: Legacy, non-standard chassis intrusion detection interface.
420 Why: The adm9240, w83792d and w83793 hardware monitoring drivers have
421 legacy interfaces for chassis intrusion detection. A standard
422 interface has been added to each driver, so the legacy interface
424 Who: Jean Delvare <khali@linux-fr.org>
426 ----------------------------
428 What: xt_connlimit rev 0
430 Who: Jan Engelhardt <jengelh@medozas.de>
431 Files: net/netfilter/xt_connlimit.c
433 ----------------------------
435 What: ipt_addrtype match include file
437 Why: superseded by xt_addrtype
438 Who: Florian Westphal <fw@strlen.de>
439 Files: include/linux/netfilter_ipv4/ipt_addrtype.h
441 ----------------------------
443 What: i2c_driver.attach_adapter
444 i2c_driver.detach_adapter
446 Why: These legacy callbacks should no longer be used as i2c-core offers
447 a variety of preferable alternative ways to instantiate I2C devices.
448 Who: Jean Delvare <khali@linux-fr.org>
450 ----------------------------
452 What: Support for driver specific ioctls in the pwc driver (everything
453 defined in media/pwc-ioctl.h)
455 Why: This stems from the v4l1 era, with v4l2 everything can be done with
456 standardized v4l2 API calls
457 Who: Hans de Goede <hdegoede@redhat.com>
459 ----------------------------
461 What: Driver specific sysfs API in the pwc driver
463 Why: Setting pan/tilt should be done with v4l2 controls, like with other
464 cams. The button is available as a standard input device
465 Who: Hans de Goede <hdegoede@redhat.com>
467 ----------------------------
469 What: Driver specific use of pixfmt.priv in the pwc driver
471 Why: The .priv field never was intended for this, setting a framerate is
472 support using the standardized S_PARM ioctl
473 Who: Hans de Goede <hdegoede@redhat.com>
475 ----------------------------
477 What: Software emulation of arbritary resolutions in the pwc driver
479 Why: The pwc driver claims to support any resolution between 160x120
480 and 640x480, but emulates this by simply drawing a black border
481 around the image. Userspace can draw its own black border if it
483 Who: Hans de Goede <hdegoede@redhat.com>
485 ----------------------------
487 What: For VIDIOC_S_FREQUENCY the type field must match the device node's type.
488 If not, return -EINVAL.
490 Why: It makes no sense to switch the tuner to radio mode by calling
491 VIDIOC_S_FREQUENCY on a video node, or to switch the tuner to tv mode by
492 calling VIDIOC_S_FREQUENCY on a radio node. This is the first step of a
493 move to more consistent handling of tv and radio tuners.
494 Who: Hans Verkuil <hans.verkuil@cisco.com>
496 ----------------------------
498 What: Opening a radio device node will no longer automatically switch the
499 tuner mode from tv to radio.
501 Why: Just opening a V4L device should not change the state of the hardware
502 like that. It's very unexpected and against the V4L spec. Instead, you
503 switch to radio mode by calling VIDIOC_S_FREQUENCY. This is the second
504 and last step of the move to consistent handling of tv and radio tuners.
505 Who: Hans Verkuil <hans.verkuil@cisco.com>
507 ----------------------------
509 What: g_file_storage driver
511 Why: This driver has been superseded by g_mass_storage.
512 Who: Alan Stern <stern@rowland.harvard.edu>
514 ----------------------------
516 What: threeg and interface sysfs files in /sys/devices/platform/acer-wmi
518 Why: In 3.0, we can now autodetect internal 3G device and already have
519 the threeg rfkill device. So, we plan to remove threeg sysfs support
520 for it's no longer necessary.
522 We also plan to remove interface sysfs file that exposed which ACPI-WMI
523 interface that was used by acer-wmi driver. It will replaced by
524 information log when acer-wmi initial.
525 Who: Lee, Chun-Yi <jlee@novell.com>
527 ----------------------------
529 What: The XFS nodelaylog mount option
531 Why: The delaylog mode that has been the default since 2.6.39 has proven
532 stable, and the old code is in the way of additional improvements in
534 Who: Christoph Hellwig <hch@lst.de>
536 ----------------------------
538 What: iwlagn alias support
540 Why: The iwlagn module has been renamed iwlwifi. The alias will be around
541 for backward compatibility for several cycles and then dropped.
542 Who: Don Fry <donald.h.fry@intel.com>