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-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. The suggested deprecation period is 3 releases.
-
----------------------------
-
-What: ddebug_query="query" boot cmdline param
-When: v3.8
-Why: obsoleted by dyndbg="query" and module.dyndbg="query"
-Who: Jim Cromie <jim.cromie@gmail.com>, Jason Baron <jbaron@redhat.com>
-
----------------------------
-
-What: CONFIG_APM_CPU_IDLE, and its ability to call APM BIOS in idle
-When: 2012
-Why: This optional sub-feature of APM is of dubious reliability,
- and ancient APM laptops are likely better served by calling HLT.
- Deleting CONFIG_APM_CPU_IDLE allows x86 to stop exporting
- the pm_idle function pointer to modules.
-Who: Len Brown <len.brown@intel.com>
-
-----------------------------
-
-What: x86_32 "no-hlt" cmdline param
-When: 2012
-Why: remove a branch from idle path, simplify code used by everybody.
- This option disabled the use of HLT in idle and machine_halt()
- for hardware that was flakey 15-years ago. Today we have
- "idle=poll" that removed HLT from idle, and so if such a machine
- is still running the upstream kernel, "idle=poll" is likely sufficient.
-Who: Len Brown <len.brown@intel.com>
-
-----------------------------
-
-What: x86 "idle=mwait" cmdline param
-When: 2012
-Why: simplify x86 idle code
-Who: Len Brown <len.brown@intel.com>
-
-----------------------------
-
-What: PRISM54
-When: 2.6.34
-
-Why: prism54 FullMAC PCI / Cardbus devices used to be supported only by the
- prism54 wireless driver. After Intersil stopped selling these
- devices in preference for the newer more flexible SoftMAC devices
- a SoftMAC device driver was required and prism54 did not support
- them. The p54pci driver now exists and has been present in the kernel for
- a while. This driver supports both SoftMAC devices and FullMAC devices.
- The main difference between these devices was the amount of memory which
- could be used for the firmware. The SoftMAC devices support a smaller
- amount of memory. Because of this the SoftMAC firmware fits into FullMAC
- devices's memory. p54pci supports not only PCI / Cardbus but also USB
- and SPI. Since p54pci supports all devices prism54 supports
- you will have a conflict. I'm not quite sure how distributions are
- handling this conflict right now. prism54 was kept around due to
- claims users may experience issues when using the SoftMAC driver.
- Time has passed users have not reported issues. If you use prism54
- and for whatever reason you cannot use p54pci please let us know!
- E-mail us at: linux-wireless@vger.kernel.org
-
- For more information see the p54 wiki page:
-
- http://wireless.kernel.org/en/users/Drivers/p54
-
-Who: Luis R. Rodriguez <lrodriguez@atheros.com>
-
----------------------------
-
-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 <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
-
----------------------------
-
-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 <lrodriguez@atheros.com>
-
----------------------------
-
-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 <pavel@ucw.cz>
-
----------------------------
-
-What: /proc/<pid>/oom_adj
-When: August 2012
-Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
- badness heuristic used to determine which task to kill when the kernel
- is out of memory.
-
- The badness heuristic has since been rewritten since the introduction of
- this tunable such that its meaning is deprecated. The value was
- implemented as a bitshift on a score generated by the badness()
- function that did not have any precise units of measure. With the
- rewrite, the score is given as a proportion of available memory to the
- task allocating pages, so using a bitshift which grows the score
- exponentially is, thus, impossible to tune with fine granularity.
-
- A much more powerful interface, /proc/<pid>/oom_score_adj, was
- introduced with the oom killer rewrite that allows users to increase or
- decrease the badness score linearly. This interface will replace
- /proc/<pid>/oom_adj.
-
- A warning will be emitted to the kernel log if an application uses this
- deprecated interface. After it is printed once, future warnings will be
- suppressed until the kernel is rebooted.
-
----------------------------
-
-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 <hch@lst.de>
-
----------------------------
-
-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 <arjan@linux.intel.com>
-
----------------------------
-
-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 <kay.sievers@suse.de>
-
----------------------------
-
-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 <rui.zhang@intel.com>
-
----------------------------
-
-What: CONFIG_ACPI_PROCFS_POWER
-When: 2.6.39
-Why: sysfs I/F for ACPI power devices, including AC and Battery,
- has been working in upstream kernel since 2.6.24, Sep 2007.
- In 2.6.37, we make the sysfs I/F always built in and this option
- disabled by default.
- Remove this option and the ACPI power procfs interface in 2.6.39.
-Who: Zhang Rui <rui.zhang@intel.com>
-
----------------------------
-
-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 <len.brown@intel.com>
-
----------------------------
-
-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 <tglx@linutronix.de>
-
----------------------------
-
-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 <dbrownell@users.sourceforge.net>
----------------------------
-
-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 <m@bues.ch>
-
----------------------------
-
-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 <kiran@scalex86.org>
-
----------------------------
-
-What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
- (in net/core/net-sysfs.c)
-When: 3.5
-Why: Over 1K .text/.data size reduction, data is available in other
- ways (ioctls)
-Who: Johannes Berg <johannes@sipsolutions.net>
-
----------------------------
-
-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 <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
-
------------------------------
-
-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 <achiang@hp.com>
-
----------------------------
-
-What: CONFIG_RFKILL_INPUT
-When: 2.6.33
-Why: Should be implemented in userspace, policy daemon.
-Who: Johannes Berg <johannes@sipsolutions.net>
-
-----------------------------
-
-What: sound-slot/service-* module aliases and related clutters in
- sound/sound_core.c
-When: August 2010
-Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
- (14) and requests modules using custom sound-slot/service-*
- module aliases. The only benefit of doing this is allowing
- use of custom module aliases which might as well be considered
- a bug at this point. This preemptive claiming prevents
- alternative OSS implementations.
-
- Till the feature is removed, the kernel will be requesting
- both sound-slot/service-* and the standard char-major-* module
- aliases and allow turning off the pre-claiming selectively via
- CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
- kernel parameter.
-
- After the transition phase is complete, both the custom module
- aliases and switches to disable it will go away. This removal
- will also allow making ALSA OSS emulation independent of
- sound_core. The dependency will be broken then too.
-Who: Tejun Heo <tj@kernel.org>
-
-----------------------------
-
-What: sysfs-class-rfkill state file
-When: Feb 2014
-Files: net/rfkill/core.c
-Why: Documented as obsolete since Feb 2010. This file is limited to 3
- states while the rfkill drivers can have 4 states.
-Who: anybody or Florian Mickler <florian@mickler.org>
-
-----------------------------
-
-What: sysfs-class-rfkill claim file
-When: Feb 2012
-Files: net/rfkill/core.c
-Why: It is not possible to claim an rfkill driver since 2007. This is
- Documented as obsolete since Feb 2010.
-Who: anybody or Florian Mickler <florian@mickler.org>
-
-----------------------------
-
-What: iwlwifi 50XX module parameters
-When: 3.0
-Why: The "..50" modules parameters were used to configure 5000 series and
- up devices; different set of module parameters also available for 4965
- with same functionalities. Consolidate both set into single place
- in drivers/net/wireless/iwlwifi/iwl-agn.c
-
-Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
-
-----------------------------
-
-What: iwl4965 alias support
-When: 3.0
-Why: Internal alias support has been present in module-init-tools for some
- time, the MODULE_ALIAS("iwl4965") boilerplate aliases can be removed
- with no impact.
-
-Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
-
----------------------------
-
-What: xt_NOTRACK
-Files: net/netfilter/xt_NOTRACK.c
-When: April 2011
-Why: Superseded by xt_CT
-Who: Netfilter developer team <netfilter-devel@vger.kernel.org>
-
-----------------------------
-
-What: IRQF_DISABLED
-When: 2.6.36
-Why: The flag is a NOOP as we run interrupt handlers with interrupts disabled
-Who: Thomas Gleixner <tglx@linutronix.de>
-
-----------------------------
-
-What: PCI DMA unmap state API
-When: August 2012
-Why: PCI DMA unmap state API (include/linux/pci-dma.h) was replaced
- with DMA unmap state API (DMA unmap state API can be used for
- any bus).
-Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
-
-----------------------------
-
-What: iwlwifi disable_hw_scan module parameters
-When: 3.0
-Why: Hareware scan is the prefer method for iwlwifi devices for
- scanning operation. Remove software scan support for all the
- iwlwifi devices.
-
-Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
-
-----------------------------
-
-What: Legacy, non-standard chassis intrusion detection interface.
-When: June 2011
-Why: The adm9240, w83792d and w83793 hardware monitoring drivers have
- legacy interfaces for chassis intrusion detection. A standard
- interface has been added to each driver, so the legacy interface
- can be removed.
-Who: Jean Delvare <khali@linux-fr.org>
-
-----------------------------
-
-What: xt_connlimit rev 0
-When: 2012
-Who: Jan Engelhardt <jengelh@medozas.de>
-Files: net/netfilter/xt_connlimit.c
-
-----------------------------
-
-What: ipt_addrtype match include file
-When: 2012
-Why: superseded by xt_addrtype
-Who: Florian Westphal <fw@strlen.de>
-Files: include/linux/netfilter_ipv4/ipt_addrtype.h
-
-----------------------------
-
-What: i2c_driver.attach_adapter
- i2c_driver.detach_adapter
-When: September 2011
-Why: These legacy callbacks should no longer be used as i2c-core offers
- a variety of preferable alternative ways to instantiate I2C devices.
-Who: Jean Delvare <khali@linux-fr.org>
-
-----------------------------
-
-What: Opening a radio device node will no longer automatically switch the
- tuner mode from tv to radio.
-When: 3.3
-Why: Just opening a V4L device should not change the state of the hardware
- like that. It's very unexpected and against the V4L spec. Instead, you
- switch to radio mode by calling VIDIOC_S_FREQUENCY. This is the second
- and last step of the move to consistent handling of tv and radio tuners.
-Who: Hans Verkuil <hans.verkuil@cisco.com>
-
-----------------------------
-
-What: g_file_storage driver
-When: 3.8
-Why: This driver has been superseded by g_mass_storage.
-Who: Alan Stern <stern@rowland.harvard.edu>
-
-----------------------------
-
-What: threeg and interface sysfs files in /sys/devices/platform/acer-wmi
-When: 2012
-Why: In 3.0, we can now autodetect internal 3G device and already have
- the threeg rfkill device. So, we plan to remove threeg sysfs support
- for it's no longer necessary.
-
- We also plan to remove interface sysfs file that exposed which ACPI-WMI
- interface that was used by acer-wmi driver. It will replaced by
- information log when acer-wmi initial.
-Who: Lee, Chun-Yi <jlee@novell.com>
-
----------------------------
-
-What: /sys/devices/platform/_UDC_/udc/_UDC_/is_dualspeed file and
- is_dualspeed line in /sys/devices/platform/ci13xxx_*/udc/device file.
-When: 3.8
-Why: The is_dualspeed file is superseded by maximum_speed in the same
- directory and is_dualspeed line in device file is superseded by
- max_speed line in the same file.
-
- The maximum_speed/max_speed specifies maximum speed supported by UDC.
- To check if dualspeeed is supported, check if the value is >= 3.
- Various possible speeds are defined in <linux/usb/ch9.h>.
-Who: Michal Nazarewicz <mina86@mina86.com>
-
-----------------------------
-
-What: The XFS nodelaylog mount option
-When: 3.3
-Why: The delaylog mode that has been the default since 2.6.39 has proven
- stable, and the old code is in the way of additional improvements in
- the log code.
-Who: Christoph Hellwig <hch@lst.de>
-
-----------------------------
-
-What: iwlagn alias support
-When: 3.5
-Why: The iwlagn module has been renamed iwlwifi. The alias will be around
- for backward compatibility for several cycles and then dropped.
-Who: Don Fry <donald.h.fry@intel.com>
-
-----------------------------
-
-What: pci_scan_bus_parented()
-When: 3.5
-Why: The pci_scan_bus_parented() interface creates a new root bus. The
- bus is created with default resources (ioport_resource and
- iomem_resource) that are always wrong, so we rely on arch code to
- correct them later. Callers of pci_scan_bus_parented() should
- convert to using pci_scan_root_bus() so they can supply a list of
- bus resources when the bus is created.
-Who: Bjorn Helgaas <bhelgaas@google.com>
-
-----------------------------
-
-What: Low Performance USB Block driver ("CONFIG_BLK_DEV_UB")
-When: 3.6
-Why: This driver provides support for USB storage devices like "USB
- sticks". As of now, it is deactivated in Debian, Fedora and
- Ubuntu. All current users can switch over to usb-storage
- (CONFIG_USB_STORAGE) which only drawback is the additional SCSI
- stack.
-Who: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
-
-----------------------------
-
-What: kmap_atomic(page, km_type)
-When: 3.5
-Why: The old kmap_atomic() with two arguments is deprecated, we only
- keep it for backward compatibility for few cycles and then drop it.
-Who: Cong Wang <amwang@redhat.com>
-
-----------------------------
-
-What: get_robust_list syscall
-When: 2013
-Why: There appear to be no production users of the get_robust_list syscall,
- and it runs the risk of leaking address locations, allowing the bypass
- of ASLR. It was only ever intended for debugging, so it should be
- removed.
-Who: Kees Cook <keescook@chromium.org>
-
-----------------------------
-
-What: Removing the pn544 raw driver.
-When: 3.6
-Why: With the introduction of the NFC HCI and SHDL kernel layers, pn544.c
- is being replaced by pn544_hci.c which is accessible through the netlink
- and socket NFC APIs. Moreover, pn544.c is outdated and does not seem to
- work properly with the latest Android stacks.
- Having 2 drivers for the same hardware is confusing and as such we
- should only keep the one following the kernel NFC APIs.
-Who: Samuel Ortiz <sameo@linux.intel.com>
-
-----------------------------
-
-What: setitimer accepts user NULL pointer (value)
-When: 3.6
-Why: setitimer is not returning -EFAULT if user pointer is NULL. This
- violates the spec.
-Who: Sasikantha Babu <sasikanth.v19@gmail.com>
-
-----------------------------
-
-What: remove bogus DV presets V4L2_DV_1080I29_97, V4L2_DV_1080I30 and
- V4L2_DV_1080I25
-When: 3.6
-Why: These HDTV formats do not exist and were added by a confused mind
- (that was me, to be precise...)
-Who: Hans Verkuil <hans.verkuil@cisco.com>
-
-----------------------------
-
-What: V4L2_CID_HCENTER, V4L2_CID_VCENTER V4L2 controls
-When: 3.7
-Why: The V4L2_CID_VCENTER, V4L2_CID_HCENTER controls have been deprecated
- for about 4 years and they are not used by any mainline driver.
- There are newer controls (V4L2_CID_PAN*, V4L2_CID_TILT*) that provide
- similar functionality.
-Who: Sylwester Nawrocki <sylvester.nawrocki@gmail.com>
-
-----------------------------
-
-What: cgroup option updates via remount
-When: March 2013
-Why: Remount currently allows changing bound subsystems and
- release_agent. Rebinding is hardly useful as it only works
- when the hierarchy is empty and release_agent itself should be
- replaced with conventional fsnotify.
-
-----------------------------
-
-What: KVM debugfs statistics
-When: 2013
-Why: KVM tracepoints provide mostly equivalent information in a much more
- flexible fashion.
-
-----------------------------
-
-What: at91-mci driver ("CONFIG_MMC_AT91")
-When: 3.7
-Why: There are two mci drivers: at91-mci and atmel-mci. The PDC support
- was added to atmel-mci as a first step to support more chips.
- Then at91-mci was kept only for old IP versions (on at91rm9200 and
- at91sam9261). The support of these IP versions has just been added
- to atmel-mci, so atmel-mci can be used for all chips.
-Who: Ludovic Desroches <ludovic.desroches@atmel.com>
-
-----------------------------
-
-What: net/wanrouter/
-When: June 2013
-Why: Unsupported/unmaintained/unused since 2.6
-
-----------------------------