[linux.git] / Documentation / feature-removal-schedule.txt

The following is a list of files and features that are going to be
removed in the kernel source tree.  Every entry should contain what
exactly is going away, why it is happening, and who is going to be doing
the work.  When the feature is removed from the kernel, it should also
be removed from this file.

---------------------------

What:	IRQF_SAMPLE_RANDOM
Check:	IRQF_SAMPLE_RANDOM
When:	July 2009

Why:	Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
	sources in the kernel's current entropy model. To resolve this, every
	input point to the kernel's entropy pool needs to better document the
	type of entropy source it actually is. This will be replaced with
	additional add_*_randomness functions in drivers/char/random.c

Who:	Robin Getz <[email protected]> & Matt Mackall <[email protected]>

---------------------------

What:	The ieee80211_regdom module parameter
When:	March 2010 / desktop catchup

Why:	This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
	and currently serves as an option for users to define an
	ISO / IEC 3166 alpha2 code for the country they are currently
	present in. Although there are userspace API replacements for this
	through nl80211 distributions haven't yet caught up with implementing
	decent alternatives through standard GUIs. Although available as an
	option through iw or wpa_supplicant its just a matter of time before
	distributions pick up good GUI options for this. The ideal solution
	would actually consist of intelligent designs which would do this for
	the user automatically even when travelling through different countries.
	Until then we leave this module parameter as a compromise.

	When userspace improves with reasonable widely-available alternatives for
	this we will no longer need this module parameter. This entry hopes that
	by the super-futuristically looking date of "March 2010" we will have
	such replacements widely available.

Who:	Luis R. Rodriguez <[email protected]>

---------------------------

What:	CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information
When:	March 2010 / desktop catchup

Why:	The old regulatory infrastructure has been replaced with a new one
	which does not require statically defined regulatory domains. We do
	not want to keep static regulatory domains in the kernel due to the
	the dynamic nature of regulatory law and localization. We kept around
	the old static definitions for the regulatory domains of:

		* US
		* JP
		* EU

	and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
	set. We will remove this option once the standard Linux desktop catches
	up with the new userspace APIs we have implemented.

Who:	Luis R. Rodriguez <[email protected]>

---------------------------

What:	dev->power.power_state
When:	July 2007
Why:	Broken design for runtime control over driver power states, confusing
	driver-internal runtime power management with:  mechanisms to support
	system-wide sleep state transitions; event codes that distinguish
	different phases of swsusp "sleep" transitions; and userspace policy
	inputs.  This framework was never widely used, and most attempts to
	use it were broken.  Drivers should instead be exposing domain-specific
	interfaces either to kernel or to userspace.
Who:	Pavel Machek <[email protected]>

---------------------------

What:	Video4Linux API 1 ioctls and from Video devices.
When:	July 2009
Files:	include/linux/videodev.h
Check:	include/linux/videodev.h
Why:	V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
	series. The old API have lots of drawbacks and don't provide enough
	means to work with all video and audio standards. The newer API is
	already available on the main drivers and should be used instead.
	Newer drivers should use v4l_compat_translate_ioctl function to handle
	old calls, replacing to newer ones.
	Decoder iocts are using internally to allow video drivers to
	communicate with video decoders. This should also be improved to allow
	V4L2 calls being translated into compatible internal ioctls.
	Compatibility ioctls will be provided, for a while, via 
	v4l1-compat module. 
Who:	Mauro Carvalho Chehab <[email protected]>

---------------------------

What:	PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
When:	November 2005
Files:	drivers/pcmcia/: pcmcia_ioctl.c
Why:	With the 16-bit PCMCIA subsystem now behaving (almost) like a
	normal hotpluggable bus, and with it using the default kernel
	infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
	control ioctl needed by cardmgr and cardctl from pcmcia-cs is
	unnecessary, and makes further cleanups and integration of the
	PCMCIA subsystem into the Linux kernel device driver model more
	difficult. The features provided by cardmgr and cardctl are either
	handled by the kernel itself now or are available in the new
	pcmciautils package available at
	http://kernel.org/pub/linux/utils/kernel/pcmcia/
Who:	Dominik Brodowski <[email protected]>

---------------------------

What:	sys_sysctl
When:	September 2010
Option: CONFIG_SYSCTL_SYSCALL
Why:	The same information is available in a more convenient from
	/proc/sys, and none of the sysctl variables appear to be
	important performance wise.

	Binary sysctls are a long standing source of subtle kernel
	bugs and security issues.

	When I looked several months ago all I could find after
	searching several distributions were 5 user space programs and
	glibc (which falls back to /proc/sys) using this syscall.

	The man page for sysctl(2) documents it as unusable for user
	space programs.

	sysctl(2) is not generally ABI compatible to a 32bit user
	space application on a 64bit and a 32bit kernel.

	For the last several months the policy has been no new binary
	sysctls and no one has put forward an argument to use them.

	Binary sysctls issues seem to keep happening appearing so
	properly deprecating them (with a warning to user space) and a
	2 year grace warning period will mean eventually we can kill
	them and end the pain.

	In the mean time individual binary sysctls can be dealt with
	in a piecewise fashion.

Who:	Eric Biederman <[email protected]>

---------------------------

What:	remove EXPORT_SYMBOL(kernel_thread)
When:	August 2006
Files:	arch/*/kernel/*_ksyms.c
Check:	kernel_thread
Why:	kernel_thread is a low-level implementation detail.  Drivers should
        use the <linux/kthread.h> API instead which shields them from
	implementation details and provides a higherlevel interface that
	prevents bugs and code duplication
Who:	Christoph Hellwig <[email protected]>

---------------------------

What:	Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
	(temporary transition config option provided until then)
	The transition config option will also be removed at the same time.
When:	before 2.6.19
Why:	Unused symbols are both increasing the size of the kernel binary
	and are often a sign of "wrong API"
Who:	Arjan van de Ven <[email protected]>

---------------------------

What:	PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
When:	October 2008
Why:	The stacking of class devices makes these values misleading and
	inconsistent.
	Class devices should not carry any of these properties, and bus
	devices have SUBSYTEM and DRIVER as a replacement.
Who:	Kay Sievers <[email protected]>

---------------------------

What:	ACPI procfs interface
When:	July 2008
Why:	ACPI sysfs conversion should be finished by January 2008.
	ACPI procfs interface will be removed in July 2008 so that
	there is enough time for the user space to catch up.
Who:	Zhang Rui <[email protected]>

---------------------------

What:	/proc/acpi/button
When:	August 2007
Why:	/proc/acpi/button has been replaced by events to the input layer
	since 2.6.20.
Who:	Len Brown <[email protected]>

---------------------------

What:	/proc/acpi/event
When:	February 2008
Why:	/proc/acpi/event has been replaced by events via the input layer
	and netlink since 2.6.23.
Who:	Len Brown <[email protected]>

---------------------------

What: libata spindown skipping and warning
When: Dec 2008
Why:  Some halt(8) implementations synchronize caches for and spin
      down libata disks because libata didn't use to spin down disk on
      system halt (only synchronized caches).
      Spin down on system halt is now implemented.  sysfs node
      /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
      spin down support is available.
      Because issuing spin down command to an already spun down disk
      makes some disks spin up just to spin down again, libata tracks
      device spindown status to skip the extra spindown command and
      warn about it.
      This is to give userspace tools the time to get updated and will
      be removed after userspace is reasonably updated.
Who:  Tejun Heo <[email protected]>

---------------------------

What:	i386/x86_64 bzImage symlinks
When:	April 2010

Why:	The i386/x86_64 merge provides a symlink to the old bzImage
	location so not yet updated user space tools, e.g. package
	scripts, do not break.
Who:	Thomas Gleixner <[email protected]>

---------------------------

What (Why):
	- include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
	  (superseded by xt_TOS/xt_tos target & match)

	- "forwarding" header files like ipt_mac.h in
	  include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/

	- xt_CONNMARK match revision 0
	  (superseded by xt_CONNMARK match revision 1)

	- xt_MARK target revisions 0 and 1
	  (superseded by xt_MARK match revision 2)

	- xt_connmark match revision 0
	  (superseded by xt_connmark match revision 1)

	- xt_conntrack match revision 0
	  (superseded by xt_conntrack match revision 1)

	- xt_iprange match revision 0,
	  include/linux/netfilter_ipv4/ipt_iprange.h
	  (superseded by xt_iprange match revision 1)

	- xt_mark match revision 0
	  (superseded by xt_mark match revision 1)

	- xt_recent: the old ipt_recent proc dir
	  (superseded by /proc/net/xt_recent)

When:	January 2009 or Linux 2.7.0, whichever comes first
Why:	Superseded by newer revisions or modules
Who:	Jan Engelhardt <[email protected]>

---------------------------

What:	GPIO autorequest on gpio_direction_{input,output}() in gpiolib
When:	February 2010
Why:	All callers should use explicit gpio_request()/gpio_free().
	The autorequest mechanism in gpiolib was provided mostly as a
	migration aid for legacy GPIO interfaces (for SOC based GPIOs).
	Those users have now largely migrated.  Platforms implementing
	the GPIO interfaces without using gpiolib will see no changes.
Who:	David Brownell <[email protected]>
---------------------------

What:	b43 support for firmware revision < 410
When:	The schedule was July 2008, but it was decided that we are going to keep the
        code as long as there are no major maintanance headaches.
	So it _could_ be removed _any_ time now, if it conflicts with something new.
Why:	The support code for the old firmware hurts code readability/maintainability
	and slightly hurts runtime performance. Bugfixes for the old firmware
	are not provided by Broadcom anymore.
Who:	Michael Buesch <[email protected]>

---------------------------

What:	usedac i386 kernel parameter
When:	2.6.27
Why:	replaced by allowdac and no dac combination
Who:	Glauber Costa <[email protected]>

---------------------------

What: print_fn_descriptor_symbol()
When: October 2009
Why:  The %pF vsprintf format provides the same functionality in a
      simpler way.  print_fn_descriptor_symbol() is deprecated but
      still present to give out-of-tree modules time to change.
Who:  Bjorn Helgaas <[email protected]>

---------------------------

What:	/sys/o2cb symlink
When:	January 2010
Why:	/sys/fs/o2cb is the proper location for this information - /sys/o2cb
	exists as a symlink for backwards compatibility for old versions of
	ocfs2-tools. 2 years should be sufficient time to phase in new versions
	which know to look in /sys/fs/o2cb.
Who:	[email protected]

---------------------------

What:	SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
	SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
When: 	June 2009
Why:    A newer version of the options have been introduced in 2005 that
	removes the limitions of the old API.  The sctp library has been
        converted to use these new options at the same time.  Any user
	space app that directly uses the old options should convert to using
	the new options.
Who:	Vlad Yasevich <[email protected]>

---------------------------

What:	Ability for non root users to shm_get hugetlb pages based on mlock
	resource limits
When:	2.6.31
Why:	Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
	have CAP_IPC_LOCK to be able to allocate shm segments backed by
	huge pages.  The mlock based rlimit check to allow shm hugetlb is
	inconsistent with mmap based allocations.  Hence it is being
	deprecated.
Who:	Ravikiran Thirumalai <[email protected]>

---------------------------

What:	CONFIG_THERMAL_HWMON
When:	January 2009
Why:	This option was introduced just to allow older lm-sensors userspace
	to keep working over the upgrade to 2.6.26. At the scheduled time of
	removal fixed lm-sensors (2.x or 3.x) should be readily available.
Who:	Rene Herman <[email protected]>

---------------------------

What:	Code that is now under CONFIG_WIRELESS_EXT_SYSFS
	(in net/core/net-sysfs.c)
When:	After the only user (hal) has seen a release with the patches
	for enough time, probably some time in 2010.
Why:	Over 1K .text/.data size reduction, data is available in other
	ways (ioctls)
Who:	Johannes Berg <[email protected]>

---------------------------

What: CONFIG_NF_CT_ACCT
When: 2.6.29
Why:  Accounting can now be enabled/disabled without kernel recompilation.
      Currently used only to set a default value for a feature that is also
      controlled by a kernel/module/sysfs/sysctl parameter.
Who:  Krzysztof Piotr Oledzki <[email protected]>

---------------------------

What:	fscher and fscpos drivers
When:	June 2009
Why:	Deprecated by the new fschmd driver.
Who:	Hans de Goede <[email protected]>
	Jean Delvare <[email protected]>

---------------------------

What:	sysfs ui for changing p4-clockmod parameters
When:	September 2009
Why:	See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
	e088e4c9cdb618675874becb91b2fd581ee707e6.
	Removal is subject to fixing any remaining bugs in ACPI which may
	cause the thermal throttling not to happen at the right time.
Who:	Dave Jones <[email protected]>, Matthew Garrett <[email protected]>

-----------------------------

What:	__do_IRQ all in one fits nothing interrupt handler
When:	2.6.32
Why:	__do_IRQ was kept for easy migration to the type flow handlers.
	More than two years of migration time is enough.
Who:	Thomas Gleixner <[email protected]>

-----------------------------

What:	obsolete generic irq defines and typedefs
When:	2.6.30
Why:	The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
	have been kept around for migration reasons. After more than two years
	it's time to remove them finally
Who:	Thomas Gleixner <[email protected]>

---------------------------

What:	fakephp and associated sysfs files in /sys/bus/pci/slots/
When:	2011
Why:	In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
	represent a machine's physical PCI slots. The change in semantics
	had userspace implications, as the hotplug core no longer allowed
	drivers to create multiple sysfs files per physical slot (required
	for multi-function devices, e.g.). fakephp was seen as a developer's
	tool only, and its interface changed. Too late, we learned that
	there were some users of the fakephp interface.

	In 2.6.30, the original fakephp interface was restored. At the same
	time, the PCI core gained the ability that fakephp provided, namely
	function-level hot-remove and hot-add.

	Since the PCI core now provides the same functionality, exposed in:

		/sys/bus/pci/rescan
		/sys/bus/pci/devices/.../remove
		/sys/bus/pci/devices/.../rescan

	there is no functional reason to maintain fakephp as well.

	We will keep the existing module so that 'modprobe fakephp' will
	present the old /sys/bus/pci/slots/... interface for compatibility,
	but users are urged to migrate their applications to the API above.

	After a reasonable transition period, we will remove the legacy
	fakephp interface.
Who:	Alex Chiang <[email protected]>

---------------------------

What:	i2c-voodoo3 driver
When:	October 2009
Why:	Superseded by tdfxfb. I2C/DDC support used to live in a separate
	driver but this caused driver conflicts.
Who:	Jean Delvare <[email protected]>
	Krzysztof Helt <[email protected]>

---------------------------

What:	CONFIG_RFKILL_INPUT
When:	2.6.33
Why:	Should be implemented in userspace, policy daemon.
Who:	Johannes Berg <[email protected]>

----------------------------

What:	CONFIG_X86_OLD_MCE
When:	2.6.32
Why:	Remove the old legacy 32bit machine check code. This has been
	superseded by the newer machine check code from the 64bit port,
	but the old version has been kept around for easier testing. Note this
	doesn't impact the old P5 and WinChip machine check handlers.
Who:	Andi Kleen <[email protected]>

----------------------------

What:	lock_policy_rwsem_* and unlock_policy_rwsem_* will not be
	exported interface anymore.
When:	2.6.33
Why:	cpu_policy_rwsem has a new cleaner definition making it local to
	cpufreq core and contained inside cpufreq.c. Other dependent
	drivers should not use it in order to safely avoid lockdep issues.
Who:	Venkatesh Pallipadi <[email protected]>
Commit	Line	Data
1da177e4 LT	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.
	6
	7	---------------------------
	8
9d9b8fb0 RG	9	What: IRQF_SAMPLE_RANDOM
	10	Check: IRQF_SAMPLE_RANDOM
	11	When: July 2009
	12
	13	Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
	14	sources in the kernel's current entropy model. To resolve this, every
	15	input point to the kernel's entropy pool needs to better document the
	16	type of entropy source it actually is. This will be replaced with
	17	additional add_*_randomness functions in drivers/char/random.c
	18
	19	Who: Robin Getz <[email protected]> & Matt Mackall <[email protected]>
	20
	21	---------------------------
	22
6ee7d330	23	What: The ieee80211_regdom module parameter
8a5117d8	24	When: March 2010 / desktop catchup
6ee7d330 LR	25
	26	Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
	27	and currently serves as an option for users to define an
	28	ISO / IEC 3166 alpha2 code for the country they are currently
	29	present in. Although there are userspace API replacements for this
	30	through nl80211 distributions haven't yet caught up with implementing
	31	decent alternatives through standard GUIs. Although available as an
	32	option through iw or wpa_supplicant its just a matter of time before
	33	distributions pick up good GUI options for this. The ideal solution
	34	would actually consist of intelligent designs which would do this for
	35	the user automatically even when travelling through different countries.
	36	Until then we leave this module parameter as a compromise.
	37
	38	When userspace improves with reasonable widely-available alternatives for
	39	this we will no longer need this module parameter. This entry hopes that
	40	by the super-futuristically looking date of "March 2010" we will have
	41	such replacements widely available.
	42
	43	Who: Luis R. Rodriguez <[email protected]>
	44
	45	---------------------------
	46
8a5117d8 LR	47	What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information
	48	When: March 2010 / desktop catchup
	49
b2e1b302 LR	50	Why: The old regulatory infrastructure has been replaced with a new one
	51	which does not require statically defined regulatory domains. We do
	52	not want to keep static regulatory domains in the kernel due to the
	53	the dynamic nature of regulatory law and localization. We kept around
	54	the old static definitions for the regulatory domains of:
8a5117d8	55
b2e1b302 LR	56	* US
	57	* JP
	58	* EU
8a5117d8	59
b2e1b302	60	and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was
8a5117d8 LR	61	set. We will remove this option once the standard Linux desktop catches
	62	up with the new userspace APIs we have implemented.
	63
b2e1b302 LR	64	Who: Luis R. Rodriguez <[email protected]>
	65
	66	---------------------------
	67
471d0558	68	What: dev->power.power_state
1ebfd79e PM	69	When: July 2007
	70	Why: Broken design for runtime control over driver power states, confusing
	71	driver-internal runtime power management with: mechanisms to support
	72	system-wide sleep state transitions; event codes that distinguish
	73	different phases of swsusp "sleep" transitions; and userspace policy
	74	inputs. This framework was never widely used, and most attempts to
	75	use it were broken. Drivers should instead be exposing domain-specific
	76	interfaces either to kernel or to userspace.
	77	Who: Pavel Machek <[email protected]>
	78
	79	---------------------------
	80
42d12f5a MCC	81	What: Video4Linux API 1 ioctls and from Video devices.
	82	When: July 2009
	83	Files: include/linux/videodev.h
	84	Check: include/linux/videodev.h
11a5a10e	85	Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
875c296b MCC	86	series. The old API have lots of drawbacks and don't provide enough
	87	means to work with all video and audio standards. The newer API is
	88	already available on the main drivers and should be used instead.
	89	Newer drivers should use v4l_compat_translate_ioctl function to handle
	90	old calls, replacing to newer ones.
	91	Decoder iocts are using internally to allow video drivers to
	92	communicate with video decoders. This should also be improved to allow
	93	V4L2 calls being translated into compatible internal ioctls.
11a5a10e MCC	94	Compatibility ioctls will be provided, for a while, via
	95	v4l1-compat module.
	96	Who: Mauro Carvalho Chehab <[email protected]>
875c296b MCC	97
	98	---------------------------
	99
bf45d9b0 DB	100	What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
	101	When: November 2005
	102	Files: drivers/pcmcia/: pcmcia_ioctl.c
	103	Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
	104	normal hotpluggable bus, and with it using the default kernel
	105	infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
	106	control ioctl needed by cardmgr and cardctl from pcmcia-cs is
	107	unnecessary, and makes further cleanups and integration of the
	108	PCMCIA subsystem into the Linux kernel device driver model more
	109	difficult. The features provided by cardmgr and cardctl are either
	110	handled by the kernel itself now or are available in the new
	111	pcmciautils package available at
	112	http://kernel.org/pub/linux/utils/kernel/pcmcia/
	113	Who: Dominik Brodowski <[email protected]>
7af4cc3f HW	114
	115	---------------------------
	116
7058cb02 EB	117	What: sys_sysctl
	118	When: September 2010
	119	Option: CONFIG_SYSCTL_SYSCALL
	120	Why: The same information is available in a more convenient from
	121	/proc/sys, and none of the sysctl variables appear to be
	122	important performance wise.
	123
	124	Binary sysctls are a long standing source of subtle kernel
	125	bugs and security issues.
	126
	127	When I looked several months ago all I could find after
	128	searching several distributions were 5 user space programs and
	129	glibc (which falls back to /proc/sys) using this syscall.
	130
	131	The man page for sysctl(2) documents it as unusable for user
	132	space programs.
	133
	134	sysctl(2) is not generally ABI compatible to a 32bit user
	135	space application on a 64bit and a 32bit kernel.
	136
	137	For the last several months the policy has been no new binary
	138	sysctls and no one has put forward an argument to use them.
	139
	140	Binary sysctls issues seem to keep happening appearing so
	141	properly deprecating them (with a warning to user space) and a
	142	2 year grace warning period will mean eventually we can kill
	143	them and end the pain.
	144
	145	In the mean time individual binary sysctls can be dealt with
	146	in a piecewise fashion.
	147
	148	Who: Eric Biederman <[email protected]>
	149
	150	---------------------------
	151
ac515898 CH	152	What: remove EXPORT_SYMBOL(kernel_thread)
	153	When: August 2006
	154	Files: arch//kernel/_ksyms.c
f0a594c1	155	Check: kernel_thread
ac515898 CH	156	Why: kernel_thread is a low-level implementation detail. Drivers should
	157	use the <linux/kthread.h> API instead which shields them from
	158	implementation details and provides a higherlevel interface that
	159	prevents bugs and code duplication
	160	Who: Christoph Hellwig <[email protected]>
	161
	162	---------------------------
	163
f71d20e9 AV	164	What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
	165	(temporary transition config option provided until then)
	166	The transition config option will also be removed at the same time.
	167	When: before 2.6.19
	168	Why: Unused symbols are both increasing the size of the kernel binary
	169	and are often a sign of "wrong API"
	170	Who: Arjan van de Ven <[email protected]>
	171
	172	---------------------------
	173
d81d9d6b	174	What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
acbd39fb	175	When: October 2008
d81d9d6b KS	176	Why: The stacking of class devices makes these values misleading and
	177	inconsistent.
	178	Class devices should not carry any of these properties, and bus
	179	devices have SUBSYTEM and DRIVER as a replacement.
	180	Who: Kay Sievers <[email protected]>
	181
	182	---------------------------
6c805d2c	183
b981c591	184	What: ACPI procfs interface
8b8eb7d8 ZR	185	When: July 2008
	186	Why: ACPI sysfs conversion should be finished by January 2008.
	187	ACPI procfs interface will be removed in July 2008 so that
	188	there is enough time for the user space to catch up.
b981c591 ZR	189	Who: Zhang Rui <[email protected]>
	190
	191	---------------------------
	192
1bb67c25 LB	193	What: /proc/acpi/button
	194	When: August 2007
	195	Why: /proc/acpi/button has been replaced by events to the input layer
	196	since 2.6.20.
	197	Who: Len Brown <[email protected]>
	198
	199	---------------------------
54b290a2	200
14e04fb3 LB	201	What: /proc/acpi/event
	202	When: February 2008
	203	Why: /proc/acpi/event has been replaced by events via the input layer
	204	and netlink since 2.6.23.
	205	Who: Len Brown <[email protected]>
	206
	207	---------------------------
	208
d9aca22c	209	What: libata spindown skipping and warning
920a4b10	210	When: Dec 2008
d9aca22c TH	211	Why: Some halt(8) implementations synchronize caches for and spin
	212	down libata disks because libata didn't use to spin down disk on
	213	system halt (only synchronized caches).
	214	Spin down on system halt is now implemented. sysfs node
	215	/sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
	216	spin down support is available.
920a4b10	217	Because issuing spin down command to an already spun down disk
d9aca22c TH	218	makes some disks spin up just to spin down again, libata tracks
	219	device spindown status to skip the extra spindown command and
	220	warn about it.
	221	This is to give userspace tools the time to get updated and will
	222	be removed after userspace is reasonably updated.
920a4b10 TH	223	Who: Tejun Heo <[email protected]>
	224
	225	---------------------------
	226
914d97fd	227	What: i386/x86_64 bzImage symlinks
19b4e7f4	228	When: April 2010
914d97fd TG	229
	230	Why: The i386/x86_64 merge provides a symlink to the old bzImage
	231	location so not yet updated user space tools, e.g. package
	232	scripts, do not break.
	233	Who: Thomas Gleixner <[email protected]>
038a5008 LT	234
	235	---------------------------
	236
f9ef8a23 JE	237	What (Why):
	238	- include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
	239	(superseded by xt_TOS/xt_tos target & match)
	240
	241	- "forwarding" header files like ipt_mac.h in
	242	include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/
	243
	244	- xt_CONNMARK match revision 0
	245	(superseded by xt_CONNMARK match revision 1)
	246
	247	- xt_MARK target revisions 0 and 1
	248	(superseded by xt_MARK match revision 2)
	249
	250	- xt_connmark match revision 0
	251	(superseded by xt_connmark match revision 1)
	252
	253	- xt_conntrack match revision 0
	254	(superseded by xt_conntrack match revision 1)
	255
	256	- xt_iprange match revision 0,
	257	include/linux/netfilter_ipv4/ipt_iprange.h
	258	(superseded by xt_iprange match revision 1)
	259
	260	- xt_mark match revision 0
	261	(superseded by xt_mark match revision 1)
	262
079aa88f JE	263	- xt_recent: the old ipt_recent proc dir
	264	(superseded by /proc/net/xt_recent)
	265
f9ef8a23 JE	266	When: January 2009 or Linux 2.7.0, whichever comes first
	267	Why: Superseded by newer revisions or modules
	268	Who: Jan Engelhardt <[email protected]>
eb189d8b MB	269
	270	---------------------------
	271
8a0cecff DB	272	What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
	273	When: February 2010
	274	Why: All callers should use explicit gpio_request()/gpio_free().
	275	The autorequest mechanism in gpiolib was provided mostly as a
	276	migration aid for legacy GPIO interfaces (for SOC based GPIOs).
	277	Those users have now largely migrated. Platforms implementing
	278	the GPIO interfaces without using gpiolib will see no changes.
	279	Who: David Brownell <[email protected]>
	280	---------------------------
	281
eb189d8b	282	What: b43 support for firmware revision < 410
c557289c MB	283	When: The schedule was July 2008, but it was decided that we are going to keep the
	284	code as long as there are no major maintanance headaches.
	285	So it _could_ be removed _any_ time now, if it conflicts with something new.
eb189d8b MB	286	Why: The support code for the old firmware hurts code readability/maintainability
	287	and slightly hurts runtime performance. Bugfixes for the old firmware
	288	are not provided by Broadcom anymore.
	289	Who: Michael Buesch <[email protected]>
e88bb415 DM	290
	291	---------------------------
	292
fae9a0d8 GC	293	What: usedac i386 kernel parameter
	294	When: 2.6.27
	295	Why: replaced by allowdac and no dac combination
	296	Who: Glauber Costa <[email protected]>
	297
52f7c21b MF	298	---------------------------
52f7c21b MF	299
c80cfb04 BH	300	What: print_fn_descriptor_symbol()
	301	When: October 2009
	302	Why: The %pF vsprintf format provides the same functionality in a
	303	simpler way. print_fn_descriptor_symbol() is deprecated but
	304	still present to give out-of-tree modules time to change.
	305	Who: Bjorn Helgaas <[email protected]>
	306
	307	---------------------------
	308
52f7c21b MF	309	What: /sys/o2cb symlink
	310	When: January 2010
	311	Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
	312	exists as a symlink for backwards compatibility for old versions of
	313	ocfs2-tools. 2 years should be sufficient time to phase in new versions
	314	which know to look in /sys/fs/o2cb.
	315	Who: [email protected]
d2f5e808 MW	316
	317	---------------------------
	318
ecbed6a4 VY	319	What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD,
	320	SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD
	321	When: June 2009
	322	Why: A newer version of the options have been introduced in 2005 that
	323	removes the limitions of the old API. The sctp library has been
	324	converted to use these new options at the same time. Any user
	325	space app that directly uses the old options should convert to using
	326	the new options.
	327	Who: Vlad Yasevich <[email protected]>
ea2aca08 DM	328
	329	---------------------------
	330
2584e517 RT	331	What: Ability for non root users to shm_get hugetlb pages based on mlock
	332	resource limits
	333	When: 2.6.31
	334	Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
	335	have CAP_IPC_LOCK to be able to allocate shm segments backed by
	336	huge pages. The mlock based rlimit check to allow shm hugetlb is
	337	inconsistent with mmap based allocations. Hence it is being
	338	deprecated.
	339	Who: Ravikiran Thirumalai <[email protected]>
	340
	341	---------------------------
	342
16d75239 RH	343	What: CONFIG_THERMAL_HWMON
	344	When: January 2009
	345	Why: This option was introduced just to allow older lm-sensors userspace
	346	to keep working over the upgrade to 2.6.26. At the scheduled time of
	347	removal fixed lm-sensors (2.x or 3.x) should be readily available.
	348	Who: Rene Herman <[email protected]>
22bb1be4 JB	349
	350	---------------------------
	351
	352	What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
	353	(in net/core/net-sysfs.c)
	354	When: After the only user (hal) has seen a release with the patches
	355	for enough time, probably some time in 2010.
	356	Why: Over 1K .text/.data size reduction, data is available in other
	357	ways (ioctls)
	358	Who: Johannes Berg <[email protected]>
58401572 KPO	359
	360	---------------------------
	361
	362	What: CONFIG_NF_CT_ACCT
	363	When: 2.6.29
	364	Why: Accounting can now be enabled/disabled without kernel recompilation.
	365	Currently used only to set a default value for a feature that is also
	366	controlled by a kernel/module/sysfs/sysctl parameter.
	367	Who: Krzysztof Piotr Oledzki <[email protected]>
	368
46dfa040 FT	369	---------------------------
46dfa040 FT	370
0589c2de HG	371	What: fscher and fscpos drivers
	372	When: June 2009
	373	Why: Deprecated by the new fschmd driver.
	374	Who: Hans de Goede <[email protected]>
	375	Jean Delvare <[email protected]>
	376
	377	---------------------------
	378
753b7aea DJ	379	What: sysfs ui for changing p4-clockmod parameters
	380	When: September 2009
	381	Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
	382	e088e4c9cdb618675874becb91b2fd581ee707e6.
	383	Removal is subject to fixing any remaining bugs in ACPI which may
	384	cause the thermal throttling not to happen at the right time.
	385	Who: Dave Jones <[email protected]>, Matthew Garrett <[email protected]>
0e57aa11 TG	386
	387	-----------------------------
	388
	389	What: __do_IRQ all in one fits nothing interrupt handler
	390	When: 2.6.32
	391	Why: __do_IRQ was kept for easy migration to the type flow handlers.
	392	More than two years of migration time is enough.
	393	Who: Thomas Gleixner <[email protected]>
cb065c06 TG	394
	395	-----------------------------
	396
	397	What: obsolete generic irq defines and typedefs
	398	When: 2.6.30
	399	Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t)
	400	have been kept around for migration reasons. After more than two years
	401	it's time to remove them finally
	402	Who: Thomas Gleixner <[email protected]>
e76e5b2c	403
f110ca48 AC	404	---------------------------
	405
	406	What: fakephp and associated sysfs files in /sys/bus/pci/slots/
	407	When: 2011
	408	Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
	409	represent a machine's physical PCI slots. The change in semantics
	410	had userspace implications, as the hotplug core no longer allowed
	411	drivers to create multiple sysfs files per physical slot (required
	412	for multi-function devices, e.g.). fakephp was seen as a developer's
	413	tool only, and its interface changed. Too late, we learned that
	414	there were some users of the fakephp interface.
	415
	416	In 2.6.30, the original fakephp interface was restored. At the same
	417	time, the PCI core gained the ability that fakephp provided, namely
	418	function-level hot-remove and hot-add.
	419
	420	Since the PCI core now provides the same functionality, exposed in:
	421
	422	/sys/bus/pci/rescan
	423	/sys/bus/pci/devices/.../remove
	424	/sys/bus/pci/devices/.../rescan
	425
	426	there is no functional reason to maintain fakephp as well.
	427
	428	We will keep the existing module so that 'modprobe fakephp' will
	429	present the old /sys/bus/pci/slots/... interface for compatibility,
	430	but users are urged to migrate their applications to the API above.
	431
	432	After a reasonable transition period, we will remove the legacy
	433	fakephp interface.
	434	Who: Alex Chiang <[email protected]>
3f307fb3 JD	435
	436	---------------------------
	437
	438	What: i2c-voodoo3 driver
	439	When: October 2009
	440	Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate
	441	driver but this caused driver conflicts.
	442	Who: Jean Delvare <[email protected]>
	443	Krzysztof Helt <[email protected]>
c64fb016 JB	444
	445	---------------------------
	446
	447	What: CONFIG_RFKILL_INPUT
	448	When: 2.6.33
	449	Why: Should be implemented in userspace, policy daemon.
	450	Who: Johannes Berg <[email protected]>
9cbc1cb8	451
45f458e9 AK	452	----------------------------
	453
	454	What: CONFIG_X86_OLD_MCE
	455	When: 2.6.32
	456	Why: Remove the old legacy 32bit machine check code. This has been
	457	superseded by the newer machine check code from the 64bit port,
	458	but the old version has been kept around for easier testing. Note this
	459	doesn't impact the old P5 and WinChip machine check handlers.
	460	Who: Andi Kleen <[email protected]>
37c90e88	461
	462	----------------------------
	463
	464	What: lock_policy_rwsem_* and unlock_policy_rwsem_* will not be
	465	exported interface anymore.
	466	When: 2.6.33
	467	Why: cpu_policy_rwsem has a new cleaner definition making it local to
	468	cpufreq core and contained inside cpufreq.c. Other dependent
	469	drivers should not use it in order to safely avoid lockdep issues.
	470	Who: Venkatesh Pallipadi <[email protected]>