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1 The following is a list of files and features that are going to be
2 removed in the kernel source tree. Every entry should contain what
3 exactly is going away, why it is happening, and who is going to be doing
4 the work. When the feature is removed from the kernel, it should also
5 be removed from this file.
7 ---------------------------
9 What: dev->power.power_state
10 When: July 2007
11 Why: Broken design for runtime control over driver power states, confusing
12 driver-internal runtime power management with: mechanisms to support
13 system-wide sleep state transitions; event codes that distinguish
14 different phases of swsusp "sleep" transitions; and userspace policy
15 inputs. This framework was never widely used, and most attempts to
16 use it were broken. Drivers should instead be exposing domain-specific
17 interfaces either to kernel or to userspace.
18 Who: Pavel Machek <pavel@suse.cz>
20 ---------------------------
22 What: old NCR53C9x driver
23 When: October 2007
24 Why: Replaced by the much better esp_scsi driver. Actual low-level
25 driver can be ported over almost trivially.
26 Who: David Miller <davem@davemloft.net>
27 Christoph Hellwig <hch@lst.de>
29 ---------------------------
31 What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
32 When: December 2008
33 Files: include/linux/video_decoder.h include/linux/videodev.h
34 Check: include/linux/video_decoder.h include/linux/videodev.h
35 Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
36 series. The old API have lots of drawbacks and don't provide enough
37 means to work with all video and audio standards. The newer API is
38 already available on the main drivers and should be used instead.
39 Newer drivers should use v4l_compat_translate_ioctl function to handle
40 old calls, replacing to newer ones.
41 Decoder iocts are using internally to allow video drivers to
42 communicate with video decoders. This should also be improved to allow
43 V4L2 calls being translated into compatible internal ioctls.
44 Compatibility ioctls will be provided, for a while, via
45 v4l1-compat module.
46 Who: Mauro Carvalho Chehab <mchehab@infradead.org>
48 ---------------------------
50 What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
51 When: November 2005
52 Files: drivers/pcmcia/: pcmcia_ioctl.c
53 Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
54 normal hotpluggable bus, and with it using the default kernel
55 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
56 control ioctl needed by cardmgr and cardctl from pcmcia-cs is
57 unnecessary, and makes further cleanups and integration of the
58 PCMCIA subsystem into the Linux kernel device driver model more
59 difficult. The features provided by cardmgr and cardctl are either
60 handled by the kernel itself now or are available in the new
61 pcmciautils package available at
62 http://kernel.org/pub/linux/utils/kernel/pcmcia/
63 Who: Dominik Brodowski <linux@brodo.de>
65 ---------------------------
67 What: sys_sysctl
68 When: September 2010
69 Option: CONFIG_SYSCTL_SYSCALL
70 Why: The same information is available in a more convenient from
71 /proc/sys, and none of the sysctl variables appear to be
72 important performance wise.
74 Binary sysctls are a long standing source of subtle kernel
75 bugs and security issues.
77 When I looked several months ago all I could find after
78 searching several distributions were 5 user space programs and
79 glibc (which falls back to /proc/sys) using this syscall.
81 The man page for sysctl(2) documents it as unusable for user
82 space programs.
84 sysctl(2) is not generally ABI compatible to a 32bit user
85 space application on a 64bit and a 32bit kernel.
87 For the last several months the policy has been no new binary
88 sysctls and no one has put forward an argument to use them.
90 Binary sysctls issues seem to keep happening appearing so
91 properly deprecating them (with a warning to user space) and a
92 2 year grace warning period will mean eventually we can kill
93 them and end the pain.
95 In the mean time individual binary sysctls can be dealt with
96 in a piecewise fashion.
98 Who: Eric Biederman <ebiederm@xmission.com>
100 ---------------------------
102 What: a.out interpreter support for ELF executables
103 When: 2.6.25
104 Files: fs/binfmt_elf.c
105 Why: Using a.out interpreters for ELF executables was a feature for
106 transition from a.out to ELF. But now it is unlikely to be still
107 needed anymore and removing it would simplify the hairy ELF
108 loader code.
109 Who: Andi Kleen <ak@suse.de>
111 ---------------------------
113 What: remove EXPORT_SYMBOL(kernel_thread)
114 When: August 2006
115 Files: arch/*/kernel/*_ksyms.c
116 Check: kernel_thread
117 Why: kernel_thread is a low-level implementation detail. Drivers should
118 use the <linux/kthread.h> API instead which shields them from
119 implementation details and provides a higherlevel interface that
120 prevents bugs and code duplication
121 Who: Christoph Hellwig <hch@lst.de>
123 ---------------------------
125 What: CONFIG_FORCED_INLINING
126 When: June 2006
127 Why: Config option is there to see if gcc is good enough. (in january
128 2006). If it is, the behavior should just be the default. If it's not,
129 the option should just go away entirely.
130 Who: Arjan van de Ven
132 ---------------------------
134 What: eepro100 network driver
135 When: January 2007
136 Why: replaced by the e100 driver
137 Who: Adrian Bunk <bunk@stusta.de>
139 ---------------------------
141 What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
142 (temporary transition config option provided until then)
143 The transition config option will also be removed at the same time.
144 When: before 2.6.19
145 Why: Unused symbols are both increasing the size of the kernel binary
146 and are often a sign of "wrong API"
147 Who: Arjan van de Ven <arjan@linux.intel.com>
149 ---------------------------
151 What: vm_ops.nopage
152 When: Soon, provided in-kernel callers have been converted
153 Why: This interface is replaced by vm_ops.fault, but it has been around
154 forever, is used by a lot of drivers, and doesn't cost much to
155 maintain.
156 Who: Nick Piggin <npiggin@suse.de>
158 ---------------------------
160 What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
161 When: October 2008
162 Why: The stacking of class devices makes these values misleading and
163 inconsistent.
164 Class devices should not carry any of these properties, and bus
165 devices have SUBSYTEM and DRIVER as a replacement.
166 Who: Kay Sievers <kay.sievers@suse.de>
168 ---------------------------
170 What: ACPI procfs interface
171 When: July 2008
172 Why: ACPI sysfs conversion should be finished by January 2008.
173 ACPI procfs interface will be removed in July 2008 so that
174 there is enough time for the user space to catch up.
175 Who: Zhang Rui <rui.zhang@intel.com>
177 ---------------------------
179 What: /proc/acpi/button
180 When: August 2007
181 Why: /proc/acpi/button has been replaced by events to the input layer
182 since 2.6.20.
183 Who: Len Brown <len.brown@intel.com>
185 ---------------------------
187 What: /proc/acpi/event
188 When: February 2008
189 Why: /proc/acpi/event has been replaced by events via the input layer
190 and netlink since 2.6.23.
191 Who: Len Brown <len.brown@intel.com>
193 ---------------------------
195 What: 'time' kernel boot parameter
196 When: January 2008
197 Why: replaced by 'printk.time=<value>' so that printk timestamps can be
198 enabled or disabled as needed
199 Who: Randy Dunlap <randy.dunlap@oracle.com>
201 ---------------------------
203 What: libata spindown skipping and warning
204 When: Dec 2008
205 Why: Some halt(8) implementations synchronize caches for and spin
206 down libata disks because libata didn't use to spin down disk on
207 system halt (only synchronized caches).
208 Spin down on system halt is now implemented. sysfs node
209 /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
210 spin down support is available.
211 Because issuing spin down command to an already spun down disk
212 makes some disks spin up just to spin down again, libata tracks
213 device spindown status to skip the extra spindown command and
214 warn about it.
215 This is to give userspace tools the time to get updated and will
216 be removed after userspace is reasonably updated.
217 Who: Tejun Heo <htejun@gmail.com>
219 ---------------------------
221 What: The arch/ppc and include/asm-ppc directories
222 When: Jun 2008
223 Why: The arch/powerpc tree is the merged architecture for ppc32 and ppc64
224 platforms. Currently there are efforts underway to port the remaining
225 arch/ppc platforms to the merged tree. New submissions to the arch/ppc
226 tree have been frozen with the 2.6.22 kernel release and that tree will
227 remain in bug-fix only mode until its scheduled removal. Platforms
228 that are not ported by June 2008 will be removed due to the lack of an
229 interested maintainer.
230 Who: linuxppc-dev@ozlabs.org
232 ---------------------------
234 What: sk98lin network driver
235 When: Feburary 2008
236 Why: In kernel tree version of driver is unmaintained. Sk98lin driver
237 replaced by the skge driver.
238 Who: Stephen Hemminger <shemminger@linux-foundation.org>
240 ---------------------------
242 What: i386/x86_64 bzImage symlinks
243 When: April 2008
245 Why: The i386/x86_64 merge provides a symlink to the old bzImage
246 location so not yet updated user space tools, e.g. package
247 scripts, do not break.
248 Who: Thomas Gleixner <tglx@linutronix.de>
250 ---------------------------
252 ---------------------------
254 What: i2c-i810, i2c-prosavage and i2c-savage4
255 When: May 2008
256 Why: These drivers are superseded by i810fb, intelfb and savagefb.
257 Who: Jean Delvare <khali@linux-fr.org>
259 ---------------------------
261 What: bcm43xx wireless network driver
262 When: 2.6.26
263 Files: drivers/net/wireless/bcm43xx
264 Why: This driver's functionality has been replaced by the
265 mac80211-based b43 and b43legacy drivers.
266 Who: John W. Linville <linville@tuxdriver.com>
268 ---------------------------
270 What: ieee80211 softmac wireless networking component
271 When: 2.6.26 (or after removal of bcm43xx and port of zd1211rw to mac80211)
272 Files: net/ieee80211/softmac
273 Why: No in-kernel drivers will depend on it any longer.
274 Who: John W. Linville <linville@tuxdriver.com>
276 ---------------------------
278 What: rc80211-simple rate control algorithm for mac80211
279 When: 2.6.26
280 Files: net/mac80211/rc80211-simple.c
281 Why: This algorithm was provided for reference but always exhibited bad
282 responsiveness and performance and has some serious flaws. It has been
283 replaced by rc80211-pid.
284 Who: Stefano Brivio <stefano.brivio@polimi.it>
286 ---------------------------
288 What (Why):
289 - include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files
290 (superseded by xt_TOS/xt_tos target & match)
292 - "forwarding" header files like ipt_mac.h in
293 include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/
295 - xt_CONNMARK match revision 0
296 (superseded by xt_CONNMARK match revision 1)
298 - xt_MARK target revisions 0 and 1
299 (superseded by xt_MARK match revision 2)
301 - xt_connmark match revision 0
302 (superseded by xt_connmark match revision 1)
304 - xt_conntrack match revision 0
305 (superseded by xt_conntrack match revision 1)
307 - xt_iprange match revision 0,
308 include/linux/netfilter_ipv4/ipt_iprange.h
309 (superseded by xt_iprange match revision 1)
311 - xt_mark match revision 0
312 (superseded by xt_mark match revision 1)
314 When: January 2009 or Linux 2.7.0, whichever comes first
315 Why: Superseded by newer revisions or modules
316 Who: Jan Engelhardt <jengelh@computergmbh.de>
318 ---------------------------
320 What: b43 support for firmware revision < 410
321 When: July 2008
322 Why: The support code for the old firmware hurts code readability/maintainability
323 and slightly hurts runtime performance. Bugfixes for the old firmware
324 are not provided by Broadcom anymore.
325 Who: Michael Buesch <mb@bu3sch.de>