Documentation/feature-removal-schedule.txt

   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.
   6
   7 ---------------------------
   8
   9 What:   V4L2 VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP
  10 When:   October 2007
  11 Why:    Broken attempt to set MPEG compression parameters. These ioctls are
  12         not able to implement the wide variety of parameters that can be set
  13         by hardware MPEG encoders. A new MPEG control mechanism was created
  14         in kernel 2.6.18 that replaces these ioctls. See the V4L2 specification
  15         (section 1.9: Extended controls) for more information on this topic.
  16 Who:    Hans Verkuil <hverkuil@xs4all.nl> and
  17         Mauro Carvalho Chehab <mchehab@infradead.org>
  18
  19 ---------------------------
  20
  21 What:   /sys/devices/.../power/state
  22         dev->power.power_state
  23         dpm_runtime_{suspend,resume)()
  24 When:   July 2007
  25 Why:    Broken design for runtime control over driver power states, confusing
  26         driver-internal runtime power management with:  mechanisms to support
  27         system-wide sleep state transitions; event codes that distinguish
  28         different phases of swsusp "sleep" transitions; and userspace policy
  29         inputs.  This framework was never widely used, and most attempts to
  30         use it were broken.  Drivers should instead be exposing domain-specific
  31         interfaces either to kernel or to userspace.
  32 Who:    Pavel Machek <pavel@suse.cz>
  33
  34 ---------------------------
  35
  36 What:   RAW driver (CONFIG_RAW_DRIVER)
  37 When:   December 2005
  38 Why:    declared obsolete since kernel 2.6.3
  39         O_DIRECT can be used instead
  40 Who:    Adrian Bunk <bunk@stusta.de>
  41
  42 ---------------------------
  43
  44 What:   raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  45 When:   June 2007
  46 Why:    Deprecated in favour of the more efficient and robust rawiso interface.
  47         Affected are applications which use the deprecated part of libraw1394
  48         (raw1394_iso_write, raw1394_start_iso_write, raw1394_start_iso_rcv,
  49         raw1394_stop_iso_rcv) or bypass libraw1394.
  50 Who:    Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>
  51
  52 ---------------------------
  53
  54 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  55 When:   December 2006
  56 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  57         series. The old API have lots of drawbacks and don't provide enough
  58         means to work with all video and audio standards. The newer API is
  59         already available on the main drivers and should be used instead.
  60         Newer drivers should use v4l_compat_translate_ioctl function to handle
  61         old calls, replacing to newer ones.
  62         Decoder iocts are using internally to allow video drivers to
  63         communicate with video decoders. This should also be improved to allow
  64         V4L2 calls being translated into compatible internal ioctls.
  65 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  66
  67 ---------------------------
  68
  69 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  70 When:   November 2005
  71 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  72 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  73         normal hotpluggable bus, and with it using the default kernel
  74         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  75         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  76         unnecessary, and makes further cleanups and integration of the
  77         PCMCIA subsystem into the Linux kernel device driver model more
  78         difficult. The features provided by cardmgr and cardctl are either
  79         handled by the kernel itself now or are available in the new
  80         pcmciautils package available at
  81         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  82 Who:    Dominik Brodowski <linux@brodo.de>
  83
  84 ---------------------------
  85
  86 What:   remove EXPORT_SYMBOL(kernel_thread)
  87 When:   August 2006
  88 Files:  arch/*/kernel/*_ksyms.c
  89 Why:    kernel_thread is a low-level implementation detail.  Drivers should
  90         use the <linux/kthread.h> API instead which shields them from
  91         implementation details and provides a higherlevel interface that
  92         prevents bugs and code duplication
  93 Who:    Christoph Hellwig <hch@lst.de>
  94
  95 ---------------------------
  96
  97 What:   CONFIG_FORCED_INLINING
  98 When:   June 2006
  99 Why:    Config option is there to see if gcc is good enough. (in january
 100         2006). If it is, the behavior should just be the default. If it's not,
 101         the option should just go away entirely.
 102 Who:    Arjan van de Ven
 103
 104 ---------------------------
 105
 106 What:   eepro100 network driver
 107 When:   January 2007
 108 Why:    replaced by the e100 driver
 109 Who:    Adrian Bunk <bunk@stusta.de>
 110
 111 ---------------------------
 112
 113 What:  drivers depending on OSS_OBSOLETE_DRIVER
 114 When:  options in 2.6.20, code in 2.6.22
 115 Why:   OSS drivers with ALSA replacements
 116 Who:   Adrian Bunk <bunk@stusta.de>
 117
 118 ---------------------------
 119
 120 What:   Usage of invalid timevals in setitimer
 121 When:   March 2007
 122 Why:    POSIX requires to validate timevals in the setitimer call. This
 123         was never done by Linux. The invalid (e.g. negative timevals) were
 124         silently converted to more or less random timeouts and intervals.
 125         Until the removal a per boot limited number of warnings is printed
 126         and the timevals are sanitized.
 127
 128 Who:    Thomas Gleixner <tglx@linutronix.de>
 129
 130 ---------------------------
 131
 132 What:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 133         (temporary transition config option provided until then)
 134         The transition config option will also be removed at the same time.
 135 When:   before 2.6.19
 136 Why:    Unused symbols are both increasing the size of the kernel binary
 137         and are often a sign of "wrong API"
 138 Who:    Arjan van de Ven <arjan@linux.intel.com>
 139
 140 ---------------------------
 141
 142 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 143 When:   February 2008
 144 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 145 Why:    The USB subsystem has changed a lot over time, and it has been
 146         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 147         that operate as fast as the USB bus allows.  Because of this, the USB
 148         subsystem will not be allowing closed source kernel drivers to
 149         register with it, after this grace period is over.  If anyone needs
 150         any help in converting their closed source drivers over to use the
 151         userspace filesystems, please contact the
 152         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 153         there will be glad to help you out.
 154 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 155
 156 ---------------------------
 157
 158 What:   Interrupt only SA_* flags
 159 When:   Januar 2007
 160 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 161         out of the signal namespace.
 162
 163 Who:    Thomas Gleixner <tglx@linutronix.de>
 164
 165 ---------------------------
 166
 167 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 168 When:   October 2008
 169 Why:    The stacking of class devices makes these values misleading and
 170         inconsistent.
 171         Class devices should not carry any of these properties, and bus
 172         devices have SUBSYTEM and DRIVER as a replacement.
 173 Who:    Kay Sievers <kay.sievers@suse.de>
 174
 175 ---------------------------
 176
 177 What:   i2c-isa
 178 When:   December 2006
 179 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 180         model. Drivers relying on it are better implemented as platform
 181         drivers.
 182 Who:    Jean Delvare <khali@linux-fr.org>
 183
 184 ---------------------------
 185
 186 What:   i2c_adapter.list
 187 When:   July 2007
 188 Why:    Superfluous, this list duplicates the one maintained by the driver
 189         core.
 190 Who:    Jean Delvare <khali@linux-fr.org>,
 191         David Brownell <dbrownell@users.sourceforge.net>
 192
 193 ---------------------------
 194
 195 What:  drivers depending on OBSOLETE_OSS
 196 When:  options in 2.6.22, code in 2.6.24
 197 Why:   OSS drivers with ALSA replacements
 198 Who:   Adrian Bunk <bunk@stusta.de>
 199
 200 ---------------------------
 201
 202 What:   ACPI hooks (X86_SPEEDSTEP_CENTRINO_ACPI) in speedstep-centrino driver
 203 When:   December 2006
 204 Why:    Speedstep-centrino driver with ACPI hooks and acpi-cpufreq driver are
 205         functionally very much similar. They talk to ACPI in same way. Only
 206         difference between them is the way they do frequency transitions.
 207         One uses MSRs and the other one uses IO ports. Functionaliy of
 208         speedstep_centrino with ACPI hooks is now merged into acpi-cpufreq.
 209         That means one common driver will support all Intel Enhanced Speedstep
 210         capable CPUs. That means less confusion over name of
 211         speedstep-centrino driver (with that driver supposed to be used on
 212         non-centrino platforms). That means less duplication of code and
 213         less maintenance effort and no possibility of these two drivers
 214         going out of sync.
 215         Current users of speedstep_centrino with ACPI hooks are requested to
 216         switch over to acpi-cpufreq driver. speedstep-centrino will continue
 217         to work using older non-ACPI static table based scheme even after this
 218         date.
 219
 220 Who:    Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 221
 222 ---------------------------
 223
 224 What:   /sys/firmware/acpi/namespace
 225 When:   2.6.21
 226 Why:    The ACPI namespace is effectively the symbol list for
 227         the BIOS.  The device names are completely arbitrary
 228         and have no place being exposed to user-space.
 229
 230         For those interested in the BIOS ACPI namespace,
 231         the BIOS can be extracted and disassembled with acpidump
 232         and iasl as documented in the pmtools package here:
 233         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 234 Who:    Len Brown <len.brown@intel.com>
 235
 236 ---------------------------
 237
 238 What:   ACPI procfs interface
 239 When:   July 2007
 240 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 241         in sysfs and the ACPI procfs interface should be removed.
 242 Who:    Zhang Rui <rui.zhang@intel.com>
 243
 244 ---------------------------
 245
 246 What:   /proc/acpi/button
 247 When:   August 2007
 248 Why:    /proc/acpi/button has been replaced by events to the input layer
 249         since 2.6.20.
 250 Who:    Len Brown <len.brown@intel.com>
 251
 252 ---------------------------
 253
 254 What:   sk98lin network driver
 255 When:   July 2007
 256 Why:    In kernel tree version of driver is unmaintained. Sk98lin driver
 257         replaced by the skge driver.
 258 Who:    Stephen Hemminger <shemminger@osdl.org>
 259
 260 ---------------------------
 261
 262 What:   Compaq touchscreen device emulation
 263 When:   Oct 2007
 264 Files:  drivers/input/tsdev.c
 265 Why:    The code says it was obsolete when it was written in 2001.
 266         tslib is a userspace library which does anything tsdev can do and
 267         much more besides in userspace where this code belongs. There is no
 268         longer any need for tsdev and applications should have converted to
 269         use tslib by now.
 270         The name "tsdev" is also extremely confusing and lots of people have
 271         it loaded when they don't need/use it.
 272 Who:    Richard Purdie <rpurdie@rpsys.net>
 273
 274 ---------------------------
 275
 276 What:   i8xx_tco watchdog driver
 277 When:   in 2.6.22
 278 Why:    the i8xx_tco watchdog driver has been replaced by the iTCO_wdt
 279         watchdog driver.
 280 Who:    Wim Van Sebroeck <wim@iguana.be>
 281
 282 ---------------------------
 283
 284 What:   Multipath cached routing support in ipv4
 285 When:   in 2.6.23
 286 Why:    Code was merged, then submitter immediately disappeared leaving
 287         us with no maintainer and lots of bugs.  The code should not have
 288         been merged in the first place, and many aspects of it's
 289         implementation are blocking more critical core networking
 290         development.  It's marked EXPERIMENTAL and no distribution
 291         enables it because it cause obscure crashes due to unfixable bugs
 292         (interfaces don't return errors so memory allocation can't be
 293         handled, calling contexts of these interfaces make handling
 294         errors impossible too because they get called after we've
 295         totally commited to creating a route object, for example).
 296         This problem has existed for years and no forward progress
 297         has ever been made, and nobody steps up to try and salvage
 298         this code, so we're going to finally just get rid of it.
 299 Who:    David S. Miller <davem@davemloft.net>
 300
 301 ---------------------------
 302
 303 What:   read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 304 When:   December 2007
 305 Why:    These functions are a leftover from 2.4 times. They have several
 306         problems:
 307         - Duplication of checks that are done in the device driver's
 308           interrupt handler
 309         - common I/O layer can't do device specific error recovery
 310         - device driver can't be notified for conditions happening during
 311           execution of the function
 312         Device drivers should issue the read device characteristics and read
 313         configuration data ccws and do the appropriate error handling
 314         themselves.
 315 Who:    Cornelia Huck <cornelia.huck@de.ibm.com>
 316
 317 ---------------------------
 318
 319 What:   i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
 320 When:   September 2007
 321 Why:    Obsolete. The new i2c-gpio driver replaces all hardware-specific
 322         I2C-over-GPIO drivers.
 323 Who:    Jean Delvare <khali@linux-fr.org>
 324
 325 ---------------------------