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:   /sys/devices/.../power/state
  10         dev->power.power_state
  11         dpm_runtime_{suspend,resume)()
  12 When:   July 2007
  13 Why:    Broken design for runtime control over driver power states, confusing
  14         driver-internal runtime power management with:  mechanisms to support
  15         system-wide sleep state transitions; event codes that distinguish
  16         different phases of swsusp "sleep" transitions; and userspace policy
  17         inputs.  This framework was never widely used, and most attempts to
  18         use it were broken.  Drivers should instead be exposing domain-specific
  19         interfaces either to kernel or to userspace.
  20 Who:    Pavel Machek <pavel@suse.cz>
  21
  22 ---------------------------
  23
  24 What:   RAW driver (CONFIG_RAW_DRIVER)
  25 When:   December 2005
  26 Why:    declared obsolete since kernel 2.6.3
  27         O_DIRECT can be used instead
  28 Who:    Adrian Bunk <bunk@stusta.de>
  29
  30 ---------------------------
  31
  32 What:   raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  33 When:   June 2007
  34 Why:    Deprecated in favour of the more efficient and robust rawiso interface.
  35         Affected are applications which use the deprecated part of libraw1394
  36         (raw1394_iso_write, raw1394_start_iso_write, raw1394_start_iso_rcv,
  37         raw1394_stop_iso_rcv) or bypass libraw1394.
  38 Who:    Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>
  39
  40 ---------------------------
  41
  42 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  43 When:   December 2006
  44 Why:    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 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  54
  55 ---------------------------
  56
  57 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  58 When:   November 2005
  59 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  60 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  61         normal hotpluggable bus, and with it using the default kernel
  62         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  63         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  64         unnecessary, and makes further cleanups and integration of the
  65         PCMCIA subsystem into the Linux kernel device driver model more
  66         difficult. The features provided by cardmgr and cardctl are either
  67         handled by the kernel itself now or are available in the new
  68         pcmciautils package available at
  69         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  70 Who:    Dominik Brodowski <linux@brodo.de>
  71
  72 ---------------------------
  73
  74 What:   remove EXPORT_SYMBOL(kernel_thread)
  75 When:   August 2006
  76 Files:  arch/*/kernel/*_ksyms.c
  77 Why:    kernel_thread is a low-level implementation detail.  Drivers should
  78         use the <linux/kthread.h> API instead which shields them from
  79         implementation details and provides a higherlevel interface that
  80         prevents bugs and code duplication
  81 Who:    Christoph Hellwig <hch@lst.de>
  82
  83 ---------------------------
  84
  85 What:   CONFIG_FORCED_INLINING
  86 When:   June 2006
  87 Why:    Config option is there to see if gcc is good enough. (in january
  88         2006). If it is, the behavior should just be the default. If it's not,
  89         the option should just go away entirely.
  90 Who:    Arjan van de Ven
  91
  92 ---------------------------
  93
  94 What:   eepro100 network driver
  95 When:   January 2007
  96 Why:    replaced by the e100 driver
  97 Who:    Adrian Bunk <bunk@stusta.de>
  98
  99 ---------------------------
 100
 101 What:  drivers depending on OSS_OBSOLETE_DRIVER
 102 When:  options in 2.6.20, code in 2.6.22
 103 Why:   OSS drivers with ALSA replacements
 104 Who:   Adrian Bunk <bunk@stusta.de>
 105
 106 ---------------------------
 107
 108 What:   pci_module_init(driver)
 109 When:   January 2007
 110 Why:    Is replaced by pci_register_driver(pci_driver).
 111 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 112
 113 ---------------------------
 114
 115 What:   Usage of invalid timevals in setitimer
 116 When:   March 2007
 117 Why:    POSIX requires to validate timevals in the setitimer call. This
 118         was never done by Linux. The invalid (e.g. negative timevals) were
 119         silently converted to more or less random timeouts and intervals.
 120         Until the removal a per boot limited number of warnings is printed
 121         and the timevals are sanitized.
 122
 123 Who:    Thomas Gleixner <tglx@linutronix.de>
 124
 125 ---------------------------
 126
 127 What:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 128         (temporary transition config option provided until then)
 129         The transition config option will also be removed at the same time.
 130 When:   before 2.6.19
 131 Why:    Unused symbols are both increasing the size of the kernel binary
 132         and are often a sign of "wrong API"
 133 Who:    Arjan van de Ven <arjan@linux.intel.com>
 134
 135 ---------------------------
 136
 137 What:   mount/umount uevents
 138 When:   February 2007
 139 Why:    These events are not correct, and do not properly let userspace know
 140         when a file system has been mounted or unmounted.  Userspace should
 141         poll the /proc/mounts file instead to detect this properly.
 142 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 143
 144 ---------------------------
 145
 146 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 147 When:   February 2008
 148 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 149 Why:    The USB subsystem has changed a lot over time, and it has been
 150         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 151         that operate as fast as the USB bus allows.  Because of this, the USB
 152         subsystem will not be allowing closed source kernel drivers to
 153         register with it, after this grace period is over.  If anyone needs
 154         any help in converting their closed source drivers over to use the
 155         userspace filesystems, please contact the
 156         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 157         there will be glad to help you out.
 158 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 159
 160 ---------------------------
 161
 162 What:   Interrupt only SA_* flags
 163 When:   Januar 2007
 164 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 165         out of the signal namespace.
 166
 167 Who:    Thomas Gleixner <tglx@linutronix.de>
 168
 169 ---------------------------
 170
 171 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 172 When:   October 2008
 173 Why:    The stacking of class devices makes these values misleading and
 174         inconsistent.
 175         Class devices should not carry any of these properties, and bus
 176         devices have SUBSYTEM and DRIVER as a replacement.
 177 Who:    Kay Sievers <kay.sievers@suse.de>
 178
 179 ---------------------------
 180
 181 What:   i2c-isa
 182 When:   December 2006
 183 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 184         model. Drivers relying on it are better implemented as platform
 185         drivers.
 186 Who:    Jean Delvare <khali@linux-fr.org>
 187
 188 ---------------------------
 189
 190 What:   i2c_adapter.dev
 191         i2c_adapter.list
 192 When:   July 2007
 193 Why:    Superfluous, given i2c_adapter.class_dev:
 194           * The "dev" was a stand-in for the physical device node that legacy
 195             drivers would not have; but now it's almost always present.  Any
 196             remaining legacy drivers must upgrade (they now trigger warnings).
 197           * The "list" duplicates class device children.
 198         The delay in removing this is so upgraded lm_sensors and libsensors
 199         can get deployed.  (Removal causes minor changes in the sysfs layout,
 200         notably the location of the adapter type name and parenting the i2c
 201         client hardware directly from their controller.)
 202 Who:    Jean Delvare <khali@linux-fr.org>,
 203         David Brownell <dbrownell@users.sourceforge.net>
 204
 205 ---------------------------
 206
 207 What:  drivers depending on OBSOLETE_OSS
 208 When:  options in 2.6.22, code in 2.6.24
 209 Why:   OSS drivers with ALSA replacements
 210 Who:   Adrian Bunk <bunk@stusta.de>
 211
 212 ---------------------------
 213
 214 What:   IPv4 only connection tracking/NAT/helpers
 215 When:   2.6.22
 216 Why:    The new layer 3 independant connection tracking replaces the old
 217         IPv4 only version. After some stabilization of the new code the
 218         old one will be removed.
 219 Who:    Patrick McHardy <kaber@trash.net>
 220
 221 ---------------------------
 222
 223 What:   ACPI hooks (X86_SPEEDSTEP_CENTRINO_ACPI) in speedstep-centrino driver
 224 When:   December 2006
 225 Why:    Speedstep-centrino driver with ACPI hooks and acpi-cpufreq driver are
 226         functionally very much similar. They talk to ACPI in same way. Only
 227         difference between them is the way they do frequency transitions.
 228         One uses MSRs and the other one uses IO ports. Functionaliy of
 229         speedstep_centrino with ACPI hooks is now merged into acpi-cpufreq.
 230         That means one common driver will support all Intel Enhanced Speedstep
 231         capable CPUs. That means less confusion over name of
 232         speedstep-centrino driver (with that driver supposed to be used on
 233         non-centrino platforms). That means less duplication of code and
 234         less maintenance effort and no possibility of these two drivers
 235         going out of sync.
 236         Current users of speedstep_centrino with ACPI hooks are requested to
 237         switch over to acpi-cpufreq driver. speedstep-centrino will continue
 238         to work using older non-ACPI static table based scheme even after this
 239         date.
 240
 241 Who:    Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 242
 243 ---------------------------
 244
 245 What:   /sys/firmware/acpi/namespace
 246 When:   2.6.21
 247 Why:    The ACPI namespace is effectively the symbol list for
 248         the BIOS.  The device names are completely arbitrary
 249         and have no place being exposed to user-space.
 250
 251         For those interested in the BIOS ACPI namespace,
 252         the BIOS can be extracted and disassembled with acpidump
 253         and iasl as documented in the pmtools package here:
 254         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 255 Who:    Len Brown <len.brown@intel.com>
 256
 257 ---------------------------
 258
 259 What:   ACPI procfs interface
 260 When:   July 2007
 261 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 262         in sysfs and the ACPI procfs interface should be removed.
 263 Who:    Zhang Rui <rui.zhang@intel.com>
 264
 265 ---------------------------
 266
 267 What:   /proc/acpi/button
 268 When:   August 2007
 269 Why:    /proc/acpi/button has been replaced by events to the input layer
 270         since 2.6.20.
 271 Who:    Len Brown <len.brown@intel.com>
 272
 273 ---------------------------
 274
 275 What:   sk98lin network driver
 276 When:   July 2007
 277 Why:    In kernel tree version of driver is unmaintained. Sk98lin driver
 278         replaced by the skge driver.
 279 Who:    Stephen Hemminger <shemminger@osdl.org>
 280
 281 ---------------------------
 282
 283 What:   Compaq touchscreen device emulation
 284 When:   Oct 2007
 285 Files:  drivers/input/tsdev.c
 286 Why:    The code says it was obsolete when it was written in 2001.
 287         tslib is a userspace library which does anything tsdev can do and
 288         much more besides in userspace where this code belongs. There is no
 289         longer any need for tsdev and applications should have converted to
 290         use tslib by now.
 291         The name "tsdev" is also extremely confusing and lots of people have
 292         it loaded when they don't need/use it.
 293 Who:    Richard Purdie <rpurdie@rpsys.net>
 294
 295 ---------------------------
 296
 297 What:   Wireless extensions over netlink (CONFIG_NET_WIRELESS_RTNETLINK)
 298 When:   with the merge of wireless-dev, 2.6.22 or later
 299 Why:    The option/code is
 300          * not enabled on most kernels
 301          * not required by any userspace tools (except an experimental one,
 302            and even there only for some parts, others use ioctl)
 303          * pointless since wext is no longer evolving and the ioctl
 304            interface needs to be kept
 305 Who:    Johannes Berg <johannes@sipsolutions.net>
 306
 307 ---------------------------
 308
 309 What:   i8xx_tco watchdog driver
 310 When:   in 2.6.22
 311 Why:    the i8xx_tco watchdog driver has been replaced by the iTCO_wdt
 312         watchdog driver.
 313 Who:    Wim Van Sebroeck <wim@iguana.be>
 314
 315 ---------------------------