542 lines
20 KiB
Plaintext
542 lines
20 KiB
Plaintext
The following is a list of files and features that are going to be
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removed in the kernel source tree. Every entry should contain what
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exactly is going away, why it is happening, and who is going to be doing
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the work. When the feature is removed from the kernel, it should also
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be removed from this file.
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---------------------------
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What: CONFIG_APM_CPU_IDLE, and its ability to call APM BIOS in idle
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When: 2012
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Why: This optional sub-feature of APM is of dubious reliability,
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and ancient APM laptops are likely better served by calling HLT.
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Deleting CONFIG_APM_CPU_IDLE allows x86 to stop exporting
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the pm_idle function pointer to modules.
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Who: Len Brown <len.brown@intel.com>
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----------------------------
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What: x86_32 "no-hlt" cmdline param
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When: 2012
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Why: remove a branch from idle path, simplify code used by everybody.
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This option disabled the use of HLT in idle and machine_halt()
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for hardware that was flakey 15-years ago. Today we have
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"idle=poll" that removed HLT from idle, and so if such a machine
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is still running the upstream kernel, "idle=poll" is likely sufficient.
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Who: Len Brown <len.brown@intel.com>
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----------------------------
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What: x86 "idle=mwait" cmdline param
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When: 2012
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Why: simplify x86 idle code
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Who: Len Brown <len.brown@intel.com>
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----------------------------
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What: PRISM54
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When: 2.6.34
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Why: prism54 FullMAC PCI / Cardbus devices used to be supported only by the
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prism54 wireless driver. After Intersil stopped selling these
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devices in preference for the newer more flexible SoftMAC devices
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a SoftMAC device driver was required and prism54 did not support
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them. The p54pci driver now exists and has been present in the kernel for
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a while. This driver supports both SoftMAC devices and FullMAC devices.
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The main difference between these devices was the amount of memory which
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could be used for the firmware. The SoftMAC devices support a smaller
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amount of memory. Because of this the SoftMAC firmware fits into FullMAC
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devices's memory. p54pci supports not only PCI / Cardbus but also USB
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and SPI. Since p54pci supports all devices prism54 supports
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you will have a conflict. I'm not quite sure how distributions are
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handling this conflict right now. prism54 was kept around due to
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claims users may experience issues when using the SoftMAC driver.
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Time has passed users have not reported issues. If you use prism54
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and for whatever reason you cannot use p54pci please let us know!
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E-mail us at: linux-wireless@vger.kernel.org
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For more information see the p54 wiki page:
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http://wireless.kernel.org/en/users/Drivers/p54
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Who: Luis R. Rodriguez <lrodriguez@atheros.com>
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---------------------------
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What: IRQF_SAMPLE_RANDOM
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Check: IRQF_SAMPLE_RANDOM
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When: July 2009
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Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
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sources in the kernel's current entropy model. To resolve this, every
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input point to the kernel's entropy pool needs to better document the
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type of entropy source it actually is. This will be replaced with
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additional add_*_randomness functions in drivers/char/random.c
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Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
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---------------------------
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What: The ieee80211_regdom module parameter
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When: March 2010 / desktop catchup
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Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
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and currently serves as an option for users to define an
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ISO / IEC 3166 alpha2 code for the country they are currently
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present in. Although there are userspace API replacements for this
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through nl80211 distributions haven't yet caught up with implementing
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decent alternatives through standard GUIs. Although available as an
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option through iw or wpa_supplicant its just a matter of time before
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distributions pick up good GUI options for this. The ideal solution
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would actually consist of intelligent designs which would do this for
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the user automatically even when travelling through different countries.
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Until then we leave this module parameter as a compromise.
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When userspace improves with reasonable widely-available alternatives for
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this we will no longer need this module parameter. This entry hopes that
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by the super-futuristically looking date of "March 2010" we will have
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such replacements widely available.
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Who: Luis R. Rodriguez <lrodriguez@atheros.com>
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---------------------------
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What: dev->power.power_state
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When: July 2007
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Why: Broken design for runtime control over driver power states, confusing
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driver-internal runtime power management with: mechanisms to support
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system-wide sleep state transitions; event codes that distinguish
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different phases of swsusp "sleep" transitions; and userspace policy
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inputs. This framework was never widely used, and most attempts to
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use it were broken. Drivers should instead be exposing domain-specific
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interfaces either to kernel or to userspace.
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Who: Pavel Machek <pavel@ucw.cz>
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---------------------------
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What: /proc/<pid>/oom_adj
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When: August 2012
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Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
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badness heuristic used to determine which task to kill when the kernel
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is out of memory.
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The badness heuristic has since been rewritten since the introduction of
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this tunable such that its meaning is deprecated. The value was
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implemented as a bitshift on a score generated by the badness()
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function that did not have any precise units of measure. With the
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rewrite, the score is given as a proportion of available memory to the
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task allocating pages, so using a bitshift which grows the score
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exponentially is, thus, impossible to tune with fine granularity.
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A much more powerful interface, /proc/<pid>/oom_score_adj, was
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introduced with the oom killer rewrite that allows users to increase or
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decrease the badness score linearly. This interface will replace
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/proc/<pid>/oom_adj.
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A warning will be emitted to the kernel log if an application uses this
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deprecated interface. After it is printed once, future warnings will be
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suppressed until the kernel is rebooted.
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---------------------------
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What: remove EXPORT_SYMBOL(kernel_thread)
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When: August 2006
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Files: arch/*/kernel/*_ksyms.c
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Check: kernel_thread
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Why: kernel_thread is a low-level implementation detail. Drivers should
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use the <linux/kthread.h> API instead which shields them from
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implementation details and provides a higherlevel interface that
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prevents bugs and code duplication
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Who: Christoph Hellwig <hch@lst.de>
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---------------------------
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What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
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(temporary transition config option provided until then)
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The transition config option will also be removed at the same time.
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When: before 2.6.19
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Why: Unused symbols are both increasing the size of the kernel binary
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and are often a sign of "wrong API"
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Who: Arjan van de Ven <arjan@linux.intel.com>
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---------------------------
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What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
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When: October 2008
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Why: The stacking of class devices makes these values misleading and
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inconsistent.
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Class devices should not carry any of these properties, and bus
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devices have SUBSYTEM and DRIVER as a replacement.
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Who: Kay Sievers <kay.sievers@suse.de>
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---------------------------
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What: ACPI procfs interface
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When: July 2008
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Why: ACPI sysfs conversion should be finished by January 2008.
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ACPI procfs interface will be removed in July 2008 so that
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there is enough time for the user space to catch up.
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Who: Zhang Rui <rui.zhang@intel.com>
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---------------------------
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What: CONFIG_ACPI_PROCFS_POWER
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When: 2.6.39
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Why: sysfs I/F for ACPI power devices, including AC and Battery,
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has been working in upstream kernel since 2.6.24, Sep 2007.
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In 2.6.37, we make the sysfs I/F always built in and this option
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disabled by default.
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Remove this option and the ACPI power procfs interface in 2.6.39.
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Who: Zhang Rui <rui.zhang@intel.com>
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---------------------------
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What: /proc/acpi/event
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When: February 2008
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Why: /proc/acpi/event has been replaced by events via the input layer
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and netlink since 2.6.23.
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Who: Len Brown <len.brown@intel.com>
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---------------------------
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What: i386/x86_64 bzImage symlinks
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When: April 2010
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Why: The i386/x86_64 merge provides a symlink to the old bzImage
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location so not yet updated user space tools, e.g. package
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scripts, do not break.
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Who: Thomas Gleixner <tglx@linutronix.de>
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---------------------------
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What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
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When: February 2010
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Why: All callers should use explicit gpio_request()/gpio_free().
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The autorequest mechanism in gpiolib was provided mostly as a
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migration aid for legacy GPIO interfaces (for SOC based GPIOs).
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Those users have now largely migrated. Platforms implementing
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the GPIO interfaces without using gpiolib will see no changes.
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Who: David Brownell <dbrownell@users.sourceforge.net>
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---------------------------
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What: b43 support for firmware revision < 410
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When: The schedule was July 2008, but it was decided that we are going to keep the
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code as long as there are no major maintanance headaches.
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So it _could_ be removed _any_ time now, if it conflicts with something new.
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Why: The support code for the old firmware hurts code readability/maintainability
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and slightly hurts runtime performance. Bugfixes for the old firmware
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are not provided by Broadcom anymore.
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Who: Michael Buesch <m@bues.ch>
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---------------------------
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What: Ability for non root users to shm_get hugetlb pages based on mlock
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resource limits
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When: 2.6.31
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Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
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have CAP_IPC_LOCK to be able to allocate shm segments backed by
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huge pages. The mlock based rlimit check to allow shm hugetlb is
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inconsistent with mmap based allocations. Hence it is being
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deprecated.
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Who: Ravikiran Thirumalai <kiran@scalex86.org>
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---------------------------
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What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
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(in net/core/net-sysfs.c)
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When: 3.5
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Why: Over 1K .text/.data size reduction, data is available in other
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ways (ioctls)
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Who: Johannes Berg <johannes@sipsolutions.net>
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---------------------------
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What: sysfs ui for changing p4-clockmod parameters
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When: September 2009
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Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
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e088e4c9cdb618675874becb91b2fd581ee707e6.
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Removal is subject to fixing any remaining bugs in ACPI which may
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cause the thermal throttling not to happen at the right time.
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Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
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-----------------------------
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What: fakephp and associated sysfs files in /sys/bus/pci/slots/
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When: 2011
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Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
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represent a machine's physical PCI slots. The change in semantics
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had userspace implications, as the hotplug core no longer allowed
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drivers to create multiple sysfs files per physical slot (required
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for multi-function devices, e.g.). fakephp was seen as a developer's
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tool only, and its interface changed. Too late, we learned that
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there were some users of the fakephp interface.
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In 2.6.30, the original fakephp interface was restored. At the same
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time, the PCI core gained the ability that fakephp provided, namely
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function-level hot-remove and hot-add.
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Since the PCI core now provides the same functionality, exposed in:
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/sys/bus/pci/rescan
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/sys/bus/pci/devices/.../remove
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/sys/bus/pci/devices/.../rescan
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there is no functional reason to maintain fakephp as well.
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We will keep the existing module so that 'modprobe fakephp' will
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present the old /sys/bus/pci/slots/... interface for compatibility,
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but users are urged to migrate their applications to the API above.
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After a reasonable transition period, we will remove the legacy
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fakephp interface.
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Who: Alex Chiang <achiang@hp.com>
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---------------------------
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What: CONFIG_RFKILL_INPUT
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When: 2.6.33
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Why: Should be implemented in userspace, policy daemon.
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Who: Johannes Berg <johannes@sipsolutions.net>
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----------------------------
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What: sound-slot/service-* module aliases and related clutters in
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sound/sound_core.c
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When: August 2010
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Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
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(14) and requests modules using custom sound-slot/service-*
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module aliases. The only benefit of doing this is allowing
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use of custom module aliases which might as well be considered
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a bug at this point. This preemptive claiming prevents
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alternative OSS implementations.
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Till the feature is removed, the kernel will be requesting
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both sound-slot/service-* and the standard char-major-* module
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aliases and allow turning off the pre-claiming selectively via
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CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
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kernel parameter.
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After the transition phase is complete, both the custom module
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aliases and switches to disable it will go away. This removal
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will also allow making ALSA OSS emulation independent of
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sound_core. The dependency will be broken then too.
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Who: Tejun Heo <tj@kernel.org>
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----------------------------
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What: sysfs-class-rfkill state file
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When: Feb 2014
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Files: net/rfkill/core.c
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Why: Documented as obsolete since Feb 2010. This file is limited to 3
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states while the rfkill drivers can have 4 states.
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Who: anybody or Florian Mickler <florian@mickler.org>
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----------------------------
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What: sysfs-class-rfkill claim file
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When: Feb 2012
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Files: net/rfkill/core.c
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Why: It is not possible to claim an rfkill driver since 2007. This is
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Documented as obsolete since Feb 2010.
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Who: anybody or Florian Mickler <florian@mickler.org>
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----------------------------
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What: iwlwifi 50XX module parameters
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When: 3.0
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Why: The "..50" modules parameters were used to configure 5000 series and
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up devices; different set of module parameters also available for 4965
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with same functionalities. Consolidate both set into single place
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in drivers/net/wireless/iwlwifi/iwl-agn.c
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Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
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----------------------------
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What: iwl4965 alias support
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When: 3.0
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Why: Internal alias support has been present in module-init-tools for some
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time, the MODULE_ALIAS("iwl4965") boilerplate aliases can be removed
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with no impact.
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Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
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---------------------------
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What: xt_NOTRACK
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Files: net/netfilter/xt_NOTRACK.c
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When: April 2011
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Why: Superseded by xt_CT
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Who: Netfilter developer team <netfilter-devel@vger.kernel.org>
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----------------------------
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What: IRQF_DISABLED
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When: 2.6.36
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Why: The flag is a NOOP as we run interrupt handlers with interrupts disabled
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Who: Thomas Gleixner <tglx@linutronix.de>
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----------------------------
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What: PCI DMA unmap state API
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When: August 2012
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Why: PCI DMA unmap state API (include/linux/pci-dma.h) was replaced
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with DMA unmap state API (DMA unmap state API can be used for
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any bus).
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Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
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----------------------------
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What: iwlwifi disable_hw_scan module parameters
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When: 3.0
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Why: Hareware scan is the prefer method for iwlwifi devices for
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scanning operation. Remove software scan support for all the
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iwlwifi devices.
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Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
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----------------------------
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What: Legacy, non-standard chassis intrusion detection interface.
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When: June 2011
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Why: The adm9240, w83792d and w83793 hardware monitoring drivers have
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legacy interfaces for chassis intrusion detection. A standard
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interface has been added to each driver, so the legacy interface
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can be removed.
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Who: Jean Delvare <khali@linux-fr.org>
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----------------------------
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What: xt_connlimit rev 0
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When: 2012
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Who: Jan Engelhardt <jengelh@medozas.de>
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Files: net/netfilter/xt_connlimit.c
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----------------------------
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What: ipt_addrtype match include file
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When: 2012
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Why: superseded by xt_addrtype
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Who: Florian Westphal <fw@strlen.de>
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Files: include/linux/netfilter_ipv4/ipt_addrtype.h
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----------------------------
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What: i2c_driver.attach_adapter
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i2c_driver.detach_adapter
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When: September 2011
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Why: These legacy callbacks should no longer be used as i2c-core offers
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a variety of preferable alternative ways to instantiate I2C devices.
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Who: Jean Delvare <khali@linux-fr.org>
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----------------------------
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What: Opening a radio device node will no longer automatically switch the
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tuner mode from tv to radio.
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When: 3.3
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Why: Just opening a V4L device should not change the state of the hardware
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like that. It's very unexpected and against the V4L spec. Instead, you
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switch to radio mode by calling VIDIOC_S_FREQUENCY. This is the second
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and last step of the move to consistent handling of tv and radio tuners.
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Who: Hans Verkuil <hans.verkuil@cisco.com>
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----------------------------
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What: g_file_storage driver
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When: 3.8
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Why: This driver has been superseded by g_mass_storage.
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Who: Alan Stern <stern@rowland.harvard.edu>
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----------------------------
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What: threeg and interface sysfs files in /sys/devices/platform/acer-wmi
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When: 2012
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Why: In 3.0, we can now autodetect internal 3G device and already have
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the threeg rfkill device. So, we plan to remove threeg sysfs support
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for it's no longer necessary.
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We also plan to remove interface sysfs file that exposed which ACPI-WMI
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interface that was used by acer-wmi driver. It will replaced by
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information log when acer-wmi initial.
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Who: Lee, Chun-Yi <jlee@novell.com>
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---------------------------
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What: /sys/devices/platform/_UDC_/udc/_UDC_/is_dualspeed file and
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is_dualspeed line in /sys/devices/platform/ci13xxx_*/udc/device file.
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When: 3.8
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Why: The is_dualspeed file is superseded by maximum_speed in the same
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directory and is_dualspeed line in device file is superseded by
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max_speed line in the same file.
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The maximum_speed/max_speed specifies maximum speed supported by UDC.
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To check if dualspeeed is supported, check if the value is >= 3.
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Various possible speeds are defined in <linux/usb/ch9.h>.
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Who: Michal Nazarewicz <mina86@mina86.com>
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----------------------------
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What: The XFS nodelaylog mount option
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When: 3.3
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Why: The delaylog mode that has been the default since 2.6.39 has proven
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stable, and the old code is in the way of additional improvements in
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the log code.
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Who: Christoph Hellwig <hch@lst.de>
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|
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----------------------------
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What: iwlagn alias support
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When: 3.5
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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: 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>
|