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diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt deleted file mode 100644 index f4d8c7105fc..00000000000 --- a/Documentation/feature-removal-schedule.txt +++ /dev/null @@ -1,639 +0,0 @@ -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: /proc/sys/vm/nr_pdflush_threads -When: 2012 -Why: Since pdflush is deprecated, the interface exported in /proc/sys/vm/ - should be removed. -Who: Wanpeng Li <liwp@linux.vnet.ibm.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: 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: 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: 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: CONFIG_CFG80211_WEXT -When: as soon as distributions ship new wireless tools, ie. wpa_supplicant 1.0 - and NetworkManager/connman/etc. that are able to use nl80211 -Why: Wireless extensions are deprecated, and userland tools are moving to - using nl80211. New drivers are no longer using wireless extensions, - and while there might still be old drivers, both new drivers and new - userland no longer needs them and they can't be used for an feature - developed in the past couple of years. As such, compatibility with - wireless extensions in new drivers will be removed. -Who: Johannes Berg <johannes@sipsolutions.net> - ----------------------------- - -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: 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: xt_recent rev 0 -When: 2013 -Who: Pablo Neira Ayuso <pablo@netfilter.org> -Files: net/netfilter/xt_recent.c - ----------------------------- - -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: 3.8 -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 - ----------------------------- - -What: V4L2 selections API target rectangle and flags unification, the - following definitions will be removed: V4L2_SEL_TGT_CROP_ACTIVE, - V4L2_SEL_TGT_COMPOSE_ACTIVE, V4L2_SUBDEV_SEL_*, V4L2_SUBDEV_SEL_FLAG_* - in favor of common V4L2_SEL_TGT_* and V4L2_SEL_FLAG_* definitions. - For more details see include/linux/v4l2-common.h. -When: 3.8 -Why: The regular V4L2 selections and the subdev selection API originally - defined distinct names for the target rectangles and flags - V4L2_SEL_* - and V4L2_SUBDEV_SEL_*. Although, it turned out that the meaning of these - target rectangles is virtually identical and the APIs were consolidated - to use single set of names - V4L2_SEL_*. This didn't involve any ABI - changes. Alias definitions were created for the original ones to avoid - any instabilities in the user space interface. After few cycles these - backward compatibility definitions will be removed. -Who: Sylwester Nawrocki <sylvester.nawrocki@gmail.com> - ----------------------------- - -What: Using V4L2_CAP_VIDEO_CAPTURE and V4L2_CAP_VIDEO_OUTPUT flags - to indicate a V4L2 memory-to-memory device capability -When: 3.8 -Why: New drivers should use new V4L2_CAP_VIDEO_M2M capability flag - to indicate a V4L2 video memory-to-memory (M2M) device and - applications can now identify a M2M video device by checking - for V4L2_CAP_VIDEO_M2M, with VIDIOC_QUERYCAP ioctl. Using ORed - V4L2_CAP_VIDEO_CAPTURE and V4L2_CAP_VIDEO_OUTPUT flags for M2M - devices is ambiguous and may lead, for example, to identifying - a M2M device as a video capture or output device. -Who: Sylwester Nawrocki <s.nawrocki@samsung.com> - ----------------------------- - -What: OMAP private DMA implementation -When: 2013 -Why: We have a DMA engine implementation; all users should be updated - to use this rather than persisting with the old APIs. The old APIs - block merging the old DMA engine implementation into the DMA - engine driver. -Who: Russell King <linux@arm.linux.org.uk>, - Santosh Shilimkar <santosh.shilimkar@ti.com> - ----------------------------- |