1The following is a list of files and features that are going to be 2removed in the kernel source tree. Every entry should contain what 3exactly is going away, why it is happening, and who is going to be doing 4the work. When the feature is removed from the kernel, it should also 5be removed from this file. 6 7--------------------------- 8 9What: old static regulatory information and ieee80211_regdom module parameter 10When: 2.6.29 11Why: The old regulatory infrastructure has been replaced with a new one 12 which does not require statically defined regulatory domains. We do 13 not want to keep static regulatory domains in the kernel due to the 14 the dynamic nature of regulatory law and localization. We kept around 15 the old static definitions for the regulatory domains of: 16 * US 17 * JP 18 * EU 19 and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was 20 set. We also kept around the ieee80211_regdom module parameter in case 21 some applications were relying on it. Changing regulatory domains 22 can now be done instead by using nl80211, as is done with iw. 23Who: Luis R. Rodriguez <lrodriguez@atheros.com> 24 25--------------------------- 26 27What: dev->power.power_state 28When: July 2007 29Why: Broken design for runtime control over driver power states, confusing 30 driver-internal runtime power management with: mechanisms to support 31 system-wide sleep state transitions; event codes that distinguish 32 different phases of swsusp "sleep" transitions; and userspace policy 33 inputs. This framework was never widely used, and most attempts to 34 use it were broken. Drivers should instead be exposing domain-specific 35 interfaces either to kernel or to userspace. 36Who: Pavel Machek <pavel@suse.cz> 37 38--------------------------- 39 40What: Video4Linux API 1 ioctls and video_decoder.h from Video devices. 41When: December 2008 42Files: include/linux/video_decoder.h include/linux/videodev.h 43Check: include/linux/video_decoder.h include/linux/videodev.h 44Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6 45 series. The old API have lots of drawbacks and don't provide enough 46 means to work with all video and audio standards. The newer API is 47 already available on the main drivers and should be used instead. 48 Newer drivers should use v4l_compat_translate_ioctl function to handle 49 old calls, replacing to newer ones. 50 Decoder iocts are using internally to allow video drivers to 51 communicate with video decoders. This should also be improved to allow 52 V4L2 calls being translated into compatible internal ioctls. 53 Compatibility ioctls will be provided, for a while, via 54 v4l1-compat module. 55Who: Mauro Carvalho Chehab <mchehab@infradead.org> 56 57--------------------------- 58 59What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl]) 60When: November 2005 61Files: drivers/pcmcia/: pcmcia_ioctl.c 62Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a 63 normal hotpluggable bus, and with it using the default kernel 64 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA 65 control ioctl needed by cardmgr and cardctl from pcmcia-cs is 66 unnecessary, and makes further cleanups and integration of the 67 PCMCIA subsystem into the Linux kernel device driver model more 68 difficult. The features provided by cardmgr and cardctl are either 69 handled by the kernel itself now or are available in the new 70 pcmciautils package available at 71 http://kernel.org/pub/linux/utils/kernel/pcmcia/ 72Who: Dominik Brodowski <linux@brodo.de> 73 74--------------------------- 75 76What: sys_sysctl 77When: September 2010 78Option: CONFIG_SYSCTL_SYSCALL 79Why: The same information is available in a more convenient from 80 /proc/sys, and none of the sysctl variables appear to be 81 important performance wise. 82 83 Binary sysctls are a long standing source of subtle kernel 84 bugs and security issues. 85 86 When I looked several months ago all I could find after 87 searching several distributions were 5 user space programs and 88 glibc (which falls back to /proc/sys) using this syscall. 89 90 The man page for sysctl(2) documents it as unusable for user 91 space programs. 92 93 sysctl(2) is not generally ABI compatible to a 32bit user 94 space application on a 64bit and a 32bit kernel. 95 96 For the last several months the policy has been no new binary 97 sysctls and no one has put forward an argument to use them. 98 99 Binary sysctls issues seem to keep happening appearing so 100 properly deprecating them (with a warning to user space) and a 101 2 year grace warning period will mean eventually we can kill 102 them and end the pain. 103 104 In the mean time individual binary sysctls can be dealt with 105 in a piecewise fashion. 106 107Who: Eric Biederman <ebiederm@xmission.com> 108 109--------------------------- 110 111What: remove EXPORT_SYMBOL(kernel_thread) 112When: August 2006 113Files: arch/*/kernel/*_ksyms.c 114Check: kernel_thread 115Why: kernel_thread is a low-level implementation detail. Drivers should 116 use the <linux/kthread.h> API instead which shields them from 117 implementation details and provides a higherlevel interface that 118 prevents bugs and code duplication 119Who: Christoph Hellwig <hch@lst.de> 120 121--------------------------- 122 123What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports 124 (temporary transition config option provided until then) 125 The transition config option will also be removed at the same time. 126When: before 2.6.19 127Why: Unused symbols are both increasing the size of the kernel binary 128 and are often a sign of "wrong API" 129Who: Arjan van de Ven <arjan@linux.intel.com> 130 131--------------------------- 132 133What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment 134When: October 2008 135Why: The stacking of class devices makes these values misleading and 136 inconsistent. 137 Class devices should not carry any of these properties, and bus 138 devices have SUBSYTEM and DRIVER as a replacement. 139Who: Kay Sievers <kay.sievers@suse.de> 140 141--------------------------- 142 143What: ACPI procfs interface 144When: July 2008 145Why: ACPI sysfs conversion should be finished by January 2008. 146 ACPI procfs interface will be removed in July 2008 so that 147 there is enough time for the user space to catch up. 148Who: Zhang Rui <rui.zhang@intel.com> 149 150--------------------------- 151 152What: /proc/acpi/button 153When: August 2007 154Why: /proc/acpi/button has been replaced by events to the input layer 155 since 2.6.20. 156Who: Len Brown <len.brown@intel.com> 157 158--------------------------- 159 160What: /proc/acpi/event 161When: February 2008 162Why: /proc/acpi/event has been replaced by events via the input layer 163 and netlink since 2.6.23. 164Who: Len Brown <len.brown@intel.com> 165 166--------------------------- 167 168What: libata spindown skipping and warning 169When: Dec 2008 170Why: Some halt(8) implementations synchronize caches for and spin 171 down libata disks because libata didn't use to spin down disk on 172 system halt (only synchronized caches). 173 Spin down on system halt is now implemented. sysfs node 174 /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if 175 spin down support is available. 176 Because issuing spin down command to an already spun down disk 177 makes some disks spin up just to spin down again, libata tracks 178 device spindown status to skip the extra spindown command and 179 warn about it. 180 This is to give userspace tools the time to get updated and will 181 be removed after userspace is reasonably updated. 182Who: Tejun Heo <htejun@gmail.com> 183 184--------------------------- 185 186What: i386/x86_64 bzImage symlinks 187When: April 2010 188 189Why: The i386/x86_64 merge provides a symlink to the old bzImage 190 location so not yet updated user space tools, e.g. package 191 scripts, do not break. 192Who: Thomas Gleixner <tglx@linutronix.de> 193 194--------------------------- 195 196What (Why): 197 - include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files 198 (superseded by xt_TOS/xt_tos target & match) 199 200 - "forwarding" header files like ipt_mac.h in 201 include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/ 202 203 - xt_CONNMARK match revision 0 204 (superseded by xt_CONNMARK match revision 1) 205 206 - xt_MARK target revisions 0 and 1 207 (superseded by xt_MARK match revision 2) 208 209 - xt_connmark match revision 0 210 (superseded by xt_connmark match revision 1) 211 212 - xt_conntrack match revision 0 213 (superseded by xt_conntrack match revision 1) 214 215 - xt_iprange match revision 0, 216 include/linux/netfilter_ipv4/ipt_iprange.h 217 (superseded by xt_iprange match revision 1) 218 219 - xt_mark match revision 0 220 (superseded by xt_mark match revision 1) 221 222 - xt_recent: the old ipt_recent proc dir 223 (superseded by /proc/net/xt_recent) 224 225When: January 2009 or Linux 2.7.0, whichever comes first 226Why: Superseded by newer revisions or modules 227Who: Jan Engelhardt <jengelh@computergmbh.de> 228 229--------------------------- 230 231What: b43 support for firmware revision < 410 232When: July 2008 233Why: The support code for the old firmware hurts code readability/maintainability 234 and slightly hurts runtime performance. Bugfixes for the old firmware 235 are not provided by Broadcom anymore. 236Who: Michael Buesch <mb@bu3sch.de> 237 238--------------------------- 239 240What: usedac i386 kernel parameter 241When: 2.6.27 242Why: replaced by allowdac and no dac combination 243Who: Glauber Costa <gcosta@redhat.com> 244 245--------------------------- 246 247What: remove HID compat support 248When: 2.6.29 249Why: needed only as a temporary solution until distros fix themselves up 250Who: Jiri Slaby <jirislaby@gmail.com> 251 252--------------------------- 253 254What: print_fn_descriptor_symbol() 255When: October 2009 256Why: The %pF vsprintf format provides the same functionality in a 257 simpler way. print_fn_descriptor_symbol() is deprecated but 258 still present to give out-of-tree modules time to change. 259Who: Bjorn Helgaas <bjorn.helgaas@hp.com> 260 261--------------------------- 262 263What: /sys/o2cb symlink 264When: January 2010 265Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb 266 exists as a symlink for backwards compatibility for old versions of 267 ocfs2-tools. 2 years should be sufficient time to phase in new versions 268 which know to look in /sys/fs/o2cb. 269Who: ocfs2-devel@oss.oracle.com 270 271--------------------------- 272 273What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD, 274 SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD 275When: June 2009 276Why: A newer version of the options have been introduced in 2005 that 277 removes the limitions of the old API. The sctp library has been 278 converted to use these new options at the same time. Any user 279 space app that directly uses the old options should convert to using 280 the new options. 281Who: Vlad Yasevich <vladislav.yasevich@hp.com> 282 283--------------------------- 284 285What: CONFIG_THERMAL_HWMON 286When: January 2009 287Why: This option was introduced just to allow older lm-sensors userspace 288 to keep working over the upgrade to 2.6.26. At the scheduled time of 289 removal fixed lm-sensors (2.x or 3.x) should be readily available. 290Who: Rene Herman <rene.herman@gmail.com> 291 292--------------------------- 293 294What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS 295 (in net/core/net-sysfs.c) 296When: After the only user (hal) has seen a release with the patches 297 for enough time, probably some time in 2010. 298Why: Over 1K .text/.data size reduction, data is available in other 299 ways (ioctls) 300Who: Johannes Berg <johannes@sipsolutions.net> 301 302--------------------------- 303 304What: CONFIG_NF_CT_ACCT 305When: 2.6.29 306Why: Accounting can now be enabled/disabled without kernel recompilation. 307 Currently used only to set a default value for a feature that is also 308 controlled by a kernel/module/sysfs/sysctl parameter. 309Who: Krzysztof Piotr Oledzki <ole@ans.pl> 310 311--------------------------- 312 313What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client() 314When: 2.6.29 (ideally) or 2.6.30 (more likely) 315Why: Deprecated by the new (standard) device driver binding model. Use 316 i2c_driver->probe() and ->remove() instead. 317Who: Jean Delvare <khali@linux-fr.org> 318 319--------------------------- 320 321What: fscher and fscpos drivers 322When: June 2009 323Why: Deprecated by the new fschmd driver. 324Who: Hans de Goede <hdegoede@redhat.com> 325 Jean Delvare <khali@linux-fr.org> 326 327--------------------------- 328 329What: SELinux "compat_net" functionality 330When: 2.6.30 at the earliest 331Why: In 2.6.18 the Secmark concept was introduced to replace the "compat_net" 332 network access control functionality of SELinux. Secmark offers both 333 better performance and greater flexibility than the "compat_net" 334 mechanism. Now that the major Linux distributions have moved to 335 Secmark, it is time to deprecate the older mechanism and start the 336 process of removing the old code. 337Who: Paul Moore <paul.moore@hp.com> 338--------------------------- 339 340What: sysfs ui for changing p4-clockmod parameters 341When: September 2009 342Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and 343 e088e4c9cdb618675874becb91b2fd581ee707e6. 344 Removal is subject to fixing any remaining bugs in ACPI which may 345 cause the thermal throttling not to happen at the right time. 346Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com> 347