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Diffstat (limited to 'Documentation/feature-removal-schedule.txt')
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diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt new file mode 100644 index 0000000..c28a2ac --- /dev/null +++ b/Documentation/feature-removal-schedule.txt @@ -0,0 +1,345 @@ +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: old static regulatory information and ieee80211_regdom module parameter +When: 2.6.29 +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 also kept around the ieee80211_regdom module parameter in case + some applications were relying on it. Changing regulatory domains + can now be done instead by using nl80211, as is done with iw. +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@suse.cz> + +--------------------------- + +What: Video4Linux API 1 ioctls and video_decoder.h from Video devices. +When: December 2008 +Files: include/linux/video_decoder.h include/linux/videodev.h +Check: include/linux/video_decoder.h 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 <mchehab@infradead.org> + +--------------------------- + +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 <linux@brodo.de> + +--------------------------- + +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 <ebiederm@xmission.com> + +--------------------------- + +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: eepro100 network driver +When: January 2007 +Why: replaced by the e100 driver +Who: Adrian Bunk <bunk@stusta.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: /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 <len.brown@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: 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 <htejun@gmail.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 (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 <jengelh@computergmbh.de> + +--------------------------- + +What: b43 support for firmware revision < 410 +When: July 2008 +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 <mb@bu3sch.de> + +--------------------------- + +What: init_mm export +When: 2.6.26 +Why: Not used in-tree. The current out-of-tree users used it to + work around problems in the CPA code which should be resolved + by now. One usecase was described to provide verification code + of the CPA operation. That's a good idea in general, but such + code / infrastructure should be in the kernel and not in some + out-of-tree driver. +Who: Thomas Gleixner <tglx@linutronix.de> + +---------------------------- + +What: usedac i386 kernel parameter +When: 2.6.27 +Why: replaced by allowdac and no dac combination +Who: Glauber Costa <gcosta@redhat.com> + +--------------------------- + +What: remove HID compat support +When: 2.6.29 +Why: needed only as a temporary solution until distros fix themselves up +Who: Jiri Slaby <jirislaby@gmail.com> + +--------------------------- + +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 <bjorn.helgaas@hp.com> + +--------------------------- + +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: ocfs2-devel@oss.oracle.com + +--------------------------- + +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 <vladislav.yasevich@hp.com> + +--------------------------- + +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 <rene.herman@gmail.com> + +--------------------------- + +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 <johannes@sipsolutions.net> + +--------------------------- + +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 <ole@ans.pl> + +--------------------------- + +What: ide-scsi (BLK_DEV_IDESCSI) +When: 2.6.29 +Why: The 2.6 kernel supports direct writing to ide CD drives, which + eliminates the need for ide-scsi. The new method is more + efficient in every way. +Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> + +--------------------------- + +What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client() +When: 2.6.29 (ideally) or 2.6.30 (more likely) +Why: Deprecated by the new (standard) device driver binding model. Use + i2c_driver->probe() and ->remove() instead. +Who: Jean Delvare <khali@linux-fr.org> |
