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: The ieee80211_regdom module parameter 10When: March 2010 / desktop catchup 11 12Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code, 13 and currently serves as an option for users to define an 14 ISO / IEC 3166 alpha2 code for the country they are currently 15 present in. Although there are userspace API replacements for this 16 through nl80211 distributions haven't yet caught up with implementing 17 decent alternatives through standard GUIs. Although available as an 18 option through iw or wpa_supplicant its just a matter of time before 19 distributions pick up good GUI options for this. The ideal solution 20 would actually consist of intelligent designs which would do this for 21 the user automatically even when travelling through different countries. 22 Until then we leave this module parameter as a compromise. 23 24 When userspace improves with reasonable widely-available alternatives for 25 this we will no longer need this module parameter. This entry hopes that 26 by the super-futuristically looking date of "March 2010" we will have 27 such replacements widely available. 28 29Who: Luis R. Rodriguez <lrodriguez@atheros.com> 30 31--------------------------- 32 33What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information 34When: March 2010 / desktop catchup 35 36Why: The old regulatory infrastructure has been replaced with a new one 37 which does not require statically defined regulatory domains. We do 38 not want to keep static regulatory domains in the kernel due to the 39 the dynamic nature of regulatory law and localization. We kept around 40 the old static definitions for the regulatory domains of: 41 42 * US 43 * JP 44 * EU 45 46 and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was 47 set. We will remove this option once the standard Linux desktop catches 48 up with the new userspace APIs we have implemented. 49 50Who: Luis R. Rodriguez <lrodriguez@atheros.com> 51 52--------------------------- 53 54What: dev->power.power_state 55When: July 2007 56Why: Broken design for runtime control over driver power states, confusing 57 driver-internal runtime power management with: mechanisms to support 58 system-wide sleep state transitions; event codes that distinguish 59 different phases of swsusp "sleep" transitions; and userspace policy 60 inputs. This framework was never widely used, and most attempts to 61 use it were broken. Drivers should instead be exposing domain-specific 62 interfaces either to kernel or to userspace. 63Who: Pavel Machek <pavel@suse.cz> 64 65--------------------------- 66 67What: Video4Linux API 1 ioctls and from Video devices. 68When: July 2009 69Files: include/linux/videodev.h 70Check: include/linux/videodev.h 71Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6 72 series. The old API have lots of drawbacks and don't provide enough 73 means to work with all video and audio standards. The newer API is 74 already available on the main drivers and should be used instead. 75 Newer drivers should use v4l_compat_translate_ioctl function to handle 76 old calls, replacing to newer ones. 77 Decoder iocts are using internally to allow video drivers to 78 communicate with video decoders. This should also be improved to allow 79 V4L2 calls being translated into compatible internal ioctls. 80 Compatibility ioctls will be provided, for a while, via 81 v4l1-compat module. 82Who: Mauro Carvalho Chehab <mchehab@infradead.org> 83 84--------------------------- 85 86What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl]) 87When: November 2005 88Files: drivers/pcmcia/: pcmcia_ioctl.c 89Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a 90 normal hotpluggable bus, and with it using the default kernel 91 infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA 92 control ioctl needed by cardmgr and cardctl from pcmcia-cs is 93 unnecessary, and makes further cleanups and integration of the 94 PCMCIA subsystem into the Linux kernel device driver model more 95 difficult. The features provided by cardmgr and cardctl are either 96 handled by the kernel itself now or are available in the new 97 pcmciautils package available at 98 http://kernel.org/pub/linux/utils/kernel/pcmcia/ 99Who: Dominik Brodowski <linux@brodo.de> 100 101--------------------------- 102 103What: sys_sysctl 104When: September 2010 105Option: CONFIG_SYSCTL_SYSCALL 106Why: The same information is available in a more convenient from 107 /proc/sys, and none of the sysctl variables appear to be 108 important performance wise. 109 110 Binary sysctls are a long standing source of subtle kernel 111 bugs and security issues. 112 113 When I looked several months ago all I could find after 114 searching several distributions were 5 user space programs and 115 glibc (which falls back to /proc/sys) using this syscall. 116 117 The man page for sysctl(2) documents it as unusable for user 118 space programs. 119 120 sysctl(2) is not generally ABI compatible to a 32bit user 121 space application on a 64bit and a 32bit kernel. 122 123 For the last several months the policy has been no new binary 124 sysctls and no one has put forward an argument to use them. 125 126 Binary sysctls issues seem to keep happening appearing so 127 properly deprecating them (with a warning to user space) and a 128 2 year grace warning period will mean eventually we can kill 129 them and end the pain. 130 131 In the mean time individual binary sysctls can be dealt with 132 in a piecewise fashion. 133 134Who: Eric Biederman <ebiederm@xmission.com> 135 136--------------------------- 137 138What: remove EXPORT_SYMBOL(kernel_thread) 139When: August 2006 140Files: arch/*/kernel/*_ksyms.c 141Check: kernel_thread 142Why: kernel_thread is a low-level implementation detail. Drivers should 143 use the <linux/kthread.h> API instead which shields them from 144 implementation details and provides a higherlevel interface that 145 prevents bugs and code duplication 146Who: Christoph Hellwig <hch@lst.de> 147 148--------------------------- 149 150What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports 151 (temporary transition config option provided until then) 152 The transition config option will also be removed at the same time. 153When: before 2.6.19 154Why: Unused symbols are both increasing the size of the kernel binary 155 and are often a sign of "wrong API" 156Who: Arjan van de Ven <arjan@linux.intel.com> 157 158--------------------------- 159 160What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment 161When: October 2008 162Why: 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. 166Who: Kay Sievers <kay.sievers@suse.de> 167 168--------------------------- 169 170What: ACPI procfs interface 171When: July 2008 172Why: 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. 175Who: Zhang Rui <rui.zhang@intel.com> 176 177--------------------------- 178 179What: /proc/acpi/button 180When: August 2007 181Why: /proc/acpi/button has been replaced by events to the input layer 182 since 2.6.20. 183Who: Len Brown <len.brown@intel.com> 184 185--------------------------- 186 187What: /proc/acpi/event 188When: February 2008 189Why: /proc/acpi/event has been replaced by events via the input layer 190 and netlink since 2.6.23. 191Who: Len Brown <len.brown@intel.com> 192 193--------------------------- 194 195What: libata spindown skipping and warning 196When: Dec 2008 197Why: Some halt(8) implementations synchronize caches for and spin 198 down libata disks because libata didn't use to spin down disk on 199 system halt (only synchronized caches). 200 Spin down on system halt is now implemented. sysfs node 201 /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if 202 spin down support is available. 203 Because issuing spin down command to an already spun down disk 204 makes some disks spin up just to spin down again, libata tracks 205 device spindown status to skip the extra spindown command and 206 warn about it. 207 This is to give userspace tools the time to get updated and will 208 be removed after userspace is reasonably updated. 209Who: Tejun Heo <htejun@gmail.com> 210 211--------------------------- 212 213What: i386/x86_64 bzImage symlinks 214When: April 2010 215 216Why: The i386/x86_64 merge provides a symlink to the old bzImage 217 location so not yet updated user space tools, e.g. package 218 scripts, do not break. 219Who: Thomas Gleixner <tglx@linutronix.de> 220 221--------------------------- 222 223What (Why): 224 - include/linux/netfilter_ipv4/ipt_TOS.h ipt_tos.h header files 225 (superseded by xt_TOS/xt_tos target & match) 226 227 - "forwarding" header files like ipt_mac.h in 228 include/linux/netfilter_ipv4/ and include/linux/netfilter_ipv6/ 229 230 - xt_CONNMARK match revision 0 231 (superseded by xt_CONNMARK match revision 1) 232 233 - xt_MARK target revisions 0 and 1 234 (superseded by xt_MARK match revision 2) 235 236 - xt_connmark match revision 0 237 (superseded by xt_connmark match revision 1) 238 239 - xt_conntrack match revision 0 240 (superseded by xt_conntrack match revision 1) 241 242 - xt_iprange match revision 0, 243 include/linux/netfilter_ipv4/ipt_iprange.h 244 (superseded by xt_iprange match revision 1) 245 246 - xt_mark match revision 0 247 (superseded by xt_mark match revision 1) 248 249 - xt_recent: the old ipt_recent proc dir 250 (superseded by /proc/net/xt_recent) 251 252When: January 2009 or Linux 2.7.0, whichever comes first 253Why: Superseded by newer revisions or modules 254Who: Jan Engelhardt <jengelh@computergmbh.de> 255 256--------------------------- 257 258What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib 259When: February 2010 260Why: All callers should use explicit gpio_request()/gpio_free(). 261 The autorequest mechanism in gpiolib was provided mostly as a 262 migration aid for legacy GPIO interfaces (for SOC based GPIOs). 263 Those users have now largely migrated. Platforms implementing 264 the GPIO interfaces without using gpiolib will see no changes. 265Who: David Brownell <dbrownell@users.sourceforge.net> 266--------------------------- 267 268What: b43 support for firmware revision < 410 269When: The schedule was July 2008, but it was decided that we are going to keep the 270 code as long as there are no major maintanance headaches. 271 So it _could_ be removed _any_ time now, if it conflicts with something new. 272Why: The support code for the old firmware hurts code readability/maintainability 273 and slightly hurts runtime performance. Bugfixes for the old firmware 274 are not provided by Broadcom anymore. 275Who: Michael Buesch <mb@bu3sch.de> 276 277--------------------------- 278 279What: usedac i386 kernel parameter 280When: 2.6.27 281Why: replaced by allowdac and no dac combination 282Who: Glauber Costa <gcosta@redhat.com> 283 284--------------------------- 285 286What: print_fn_descriptor_symbol() 287When: October 2009 288Why: The %pF vsprintf format provides the same functionality in a 289 simpler way. print_fn_descriptor_symbol() is deprecated but 290 still present to give out-of-tree modules time to change. 291Who: Bjorn Helgaas <bjorn.helgaas@hp.com> 292 293--------------------------- 294 295What: /sys/o2cb symlink 296When: January 2010 297Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb 298 exists as a symlink for backwards compatibility for old versions of 299 ocfs2-tools. 2 years should be sufficient time to phase in new versions 300 which know to look in /sys/fs/o2cb. 301Who: ocfs2-devel@oss.oracle.com 302 303--------------------------- 304 305What: SCTP_GET_PEER_ADDRS_NUM_OLD, SCTP_GET_PEER_ADDRS_OLD, 306 SCTP_GET_LOCAL_ADDRS_NUM_OLD, SCTP_GET_LOCAL_ADDRS_OLD 307When: June 2009 308Why: A newer version of the options have been introduced in 2005 that 309 removes the limitions of the old API. The sctp library has been 310 converted to use these new options at the same time. Any user 311 space app that directly uses the old options should convert to using 312 the new options. 313Who: Vlad Yasevich <vladislav.yasevich@hp.com> 314 315--------------------------- 316 317What: Ability for non root users to shm_get hugetlb pages based on mlock 318 resource limits 319When: 2.6.31 320Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or 321 have CAP_IPC_LOCK to be able to allocate shm segments backed by 322 huge pages. The mlock based rlimit check to allow shm hugetlb is 323 inconsistent with mmap based allocations. Hence it is being 324 deprecated. 325Who: Ravikiran Thirumalai <kiran@scalex86.org> 326 327--------------------------- 328 329What: CONFIG_THERMAL_HWMON 330When: January 2009 331Why: This option was introduced just to allow older lm-sensors userspace 332 to keep working over the upgrade to 2.6.26. At the scheduled time of 333 removal fixed lm-sensors (2.x or 3.x) should be readily available. 334Who: Rene Herman <rene.herman@gmail.com> 335 336--------------------------- 337 338What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS 339 (in net/core/net-sysfs.c) 340When: After the only user (hal) has seen a release with the patches 341 for enough time, probably some time in 2010. 342Why: Over 1K .text/.data size reduction, data is available in other 343 ways (ioctls) 344Who: Johannes Berg <johannes@sipsolutions.net> 345 346--------------------------- 347 348What: CONFIG_NF_CT_ACCT 349When: 2.6.29 350Why: Accounting can now be enabled/disabled without kernel recompilation. 351 Currently used only to set a default value for a feature that is also 352 controlled by a kernel/module/sysfs/sysctl parameter. 353Who: Krzysztof Piotr Oledzki <ole@ans.pl> 354 355--------------------------- 356 357What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client(), 358 i2c_adapter->client_register(), i2c_adapter->client_unregister 359When: 2.6.30 360Check: i2c_attach_client i2c_detach_client 361Why: Deprecated by the new (standard) device driver binding model. Use 362 i2c_driver->probe() and ->remove() instead. 363Who: Jean Delvare <khali@linux-fr.org> 364 365--------------------------- 366 367What: fscher and fscpos drivers 368When: June 2009 369Why: Deprecated by the new fschmd driver. 370Who: Hans de Goede <hdegoede@redhat.com> 371 Jean Delvare <khali@linux-fr.org> 372 373--------------------------- 374 375What: sysfs ui for changing p4-clockmod parameters 376When: September 2009 377Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and 378 e088e4c9cdb618675874becb91b2fd581ee707e6. 379 Removal is subject to fixing any remaining bugs in ACPI which may 380 cause the thermal throttling not to happen at the right time. 381Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com> 382 383----------------------------- 384 385What: __do_IRQ all in one fits nothing interrupt handler 386When: 2.6.32 387Why: __do_IRQ was kept for easy migration to the type flow handlers. 388 More than two years of migration time is enough. 389Who: Thomas Gleixner <tglx@linutronix.de> 390 391----------------------------- 392 393What: obsolete generic irq defines and typedefs 394When: 2.6.30 395Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t) 396 have been kept around for migration reasons. After more than two years 397 it's time to remove them finally 398Who: Thomas Gleixner <tglx@linutronix.de> 399 400--------------------------- 401 402What: fakephp and associated sysfs files in /sys/bus/pci/slots/ 403When: 2011 404Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to 405 represent a machine's physical PCI slots. The change in semantics 406 had userspace implications, as the hotplug core no longer allowed 407 drivers to create multiple sysfs files per physical slot (required 408 for multi-function devices, e.g.). fakephp was seen as a developer's 409 tool only, and its interface changed. Too late, we learned that 410 there were some users of the fakephp interface. 411 412 In 2.6.30, the original fakephp interface was restored. At the same 413 time, the PCI core gained the ability that fakephp provided, namely 414 function-level hot-remove and hot-add. 415 416 Since the PCI core now provides the same functionality, exposed in: 417 418 /sys/bus/pci/rescan 419 /sys/bus/pci/devices/.../remove 420 /sys/bus/pci/devices/.../rescan 421 422 there is no functional reason to maintain fakephp as well. 423 424 We will keep the existing module so that 'modprobe fakephp' will 425 present the old /sys/bus/pci/slots/... interface for compatibility, 426 but users are urged to migrate their applications to the API above. 427 428 After a reasonable transition period, we will remove the legacy 429 fakephp interface. 430Who: Alex Chiang <achiang@hp.com> 431 432--------------------------- 433 434What: i2c-voodoo3 driver 435When: October 2009 436Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate 437 driver but this caused driver conflicts. 438Who: Jean Delvare <khali@linux-fr.org> 439 Krzysztof Helt <krzysztof.h1@wp.pl> 440