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:   dv1394 driver (CONFIG_IEEE1394_DV1394)
  43 When:   June 2007
  44 Why:    Replaced by raw1394 + userspace libraries, notably libiec61883.  This
  45         shift of application support has been indicated on www.linux1394.org
  46         and developers' mailinglists for quite some time.  Major applications
  47         have been converted, with the exception of ffmpeg and hence xine.
  48         Piped output of dvgrab2 is a partial equivalent to dv1394.
  49 Who:    Dan Dennedy <dan@dennedy.org>, Stefan Richter <stefanr@s5r6.in-berlin.de>
  50
  51 ---------------------------
  52
  53 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  54 When:   December 2006
  55 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  56         series. The old API have lots of drawbacks and don't provide enough
  57         means to work with all video and audio standards. The newer API is
  58         already available on the main drivers and should be used instead.
  59         Newer drivers should use v4l_compat_translate_ioctl function to handle
  60         old calls, replacing to newer ones.
  61         Decoder iocts are using internally to allow video drivers to
  62         communicate with video decoders. This should also be improved to allow
  63         V4L2 calls being translated into compatible internal ioctls.
  64 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  65
  66 ---------------------------
  67
  68 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  69 When:   November 2005
  70 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  71 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  72         normal hotpluggable bus, and with it using the default kernel
  73         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  74         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  75         unnecessary, and makes further cleanups and integration of the
  76         PCMCIA subsystem into the Linux kernel device driver model more
  77         difficult. The features provided by cardmgr and cardctl are either
  78         handled by the kernel itself now or are available in the new
  79         pcmciautils package available at
  80         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  81 Who:    Dominik Brodowski <linux@brodo.de>
  82
  83 ---------------------------
  84
  85 What:   remove EXPORT_SYMBOL(kernel_thread)
  86 When:   August 2006
  87 Files:  arch/*/kernel/*_ksyms.c
  88 Why:    kernel_thread is a low-level implementation detail.  Drivers should
  89         use the <linux/kthread.h> API instead which shields them from
  90         implementation details and provides a higherlevel interface that
  91         prevents bugs and code duplication
  92 Who:    Christoph Hellwig <hch@lst.de>
  93
  94 ---------------------------
  95
  96 What:   CONFIG_FORCED_INLINING
  97 When:   June 2006
  98 Why:    Config option is there to see if gcc is good enough. (in january
  99         2006). If it is, the behavior should just be the default. If it's not,
 100         the option should just go away entirely.
 101 Who:    Arjan van de Ven
 102
 103 ---------------------------
 104
 105 What:   eepro100 network driver
 106 When:   January 2007
 107 Why:    replaced by the e100 driver
 108 Who:    Adrian Bunk <bunk@stusta.de>
 109
 110 ---------------------------
 111
 112 What:  drivers depending on OSS_OBSOLETE_DRIVER
 113 When:  options in 2.6.20, code in 2.6.22
 114 Why:   OSS drivers with ALSA replacements
 115 Who:   Adrian Bunk <bunk@stusta.de>
 116
 117 ---------------------------
 118
 119 What:   pci_module_init(driver)
 120 When:   January 2007
 121 Why:    Is replaced by pci_register_driver(pci_driver).
 122 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 123
 124 ---------------------------
 125
 126 What:   Usage of invalid timevals in setitimer
 127 When:   March 2007
 128 Why:    POSIX requires to validate timevals in the setitimer call. This
 129         was never done by Linux. The invalid (e.g. negative timevals) were
 130         silently converted to more or less random timeouts and intervals.
 131         Until the removal a per boot limited number of warnings is printed
 132         and the timevals are sanitized.
 133
 134 Who:    Thomas Gleixner <tglx@linutronix.de>
 135
 136 ---------------------------
 137
 138 What:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 139         (temporary transition config option provided until then)
 140         The transition config option will also be removed at the same time.
 141 When:   before 2.6.19
 142 Why:    Unused symbols are both increasing the size of the kernel binary
 143         and are often a sign of "wrong API"
 144 Who:    Arjan van de Ven <arjan@linux.intel.com>
 145
 146 ---------------------------
 147
 148 What:   mount/umount uevents
 149 When:   February 2007
 150 Why:    These events are not correct, and do not properly let userspace know
 151         when a file system has been mounted or unmounted.  Userspace should
 152         poll the /proc/mounts file instead to detect this properly.
 153 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 154
 155 ---------------------------
 156
 157 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 158 When:   February 2008
 159 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 160 Why:    The USB subsystem has changed a lot over time, and it has been
 161         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 162         that operate as fast as the USB bus allows.  Because of this, the USB
 163         subsystem will not be allowing closed source kernel drivers to
 164         register with it, after this grace period is over.  If anyone needs
 165         any help in converting their closed source drivers over to use the
 166         userspace filesystems, please contact the
 167         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 168         there will be glad to help you out.
 169 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 170
 171 ---------------------------
 172
 173 What:   Interrupt only SA_* flags
 174 When:   Januar 2007
 175 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 176         out of the signal namespace.
 177
 178 Who:    Thomas Gleixner <tglx@linutronix.de>
 179
 180 ---------------------------
 181
 182 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 183 When:   October 2008
 184 Why:    The stacking of class devices makes these values misleading and
 185         inconsistent.
 186         Class devices should not carry any of these properties, and bus
 187         devices have SUBSYTEM and DRIVER as a replacement.
 188 Who:    Kay Sievers <kay.sievers@suse.de>
 189
 190 ---------------------------
 191
 192 What:   i2c-isa
 193 When:   December 2006
 194 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 195         model. Drivers relying on it are better implemented as platform
 196         drivers.
 197 Who:    Jean Delvare <khali@linux-fr.org>
 198
 199 ---------------------------
 200
 201 What:   i2c_adapter.dev
 202         i2c_adapter.list
 203 When:   July 2007
 204 Why:    Superfluous, given i2c_adapter.class_dev:
 205           * The "dev" was a stand-in for the physical device node that legacy
 206             drivers would not have; but now it's almost always present.  Any
 207             remaining legacy drivers must upgrade (they now trigger warnings).
 208           * The "list" duplicates class device children.
 209         The delay in removing this is so upgraded lm_sensors and libsensors
 210         can get deployed.  (Removal causes minor changes in the sysfs layout,
 211         notably the location of the adapter type name and parenting the i2c
 212         client hardware directly from their controller.)
 213 Who:    Jean Delvare <khali@linux-fr.org>,
 214         David Brownell <dbrownell@users.sourceforge.net>
 215
 216 ---------------------------
 217
 218 What:  drivers depending on OBSOLETE_OSS
 219 When:  options in 2.6.22, code in 2.6.24
 220 Why:   OSS drivers with ALSA replacements
 221 Who:   Adrian Bunk <bunk@stusta.de>
 222
 223 ---------------------------
 224
 225 What:   IPv4 only connection tracking/NAT/helpers
 226 When:   2.6.22
 227 Why:    The new layer 3 independant connection tracking replaces the old
 228         IPv4 only version. After some stabilization of the new code the
 229         old one will be removed.
 230 Who:    Patrick McHardy <kaber@trash.net>
 231
 232 ---------------------------
 233
 234 What:   ACPI hooks (X86_SPEEDSTEP_CENTRINO_ACPI) in speedstep-centrino driver
 235 When:   December 2006
 236 Why:    Speedstep-centrino driver with ACPI hooks and acpi-cpufreq driver are
 237         functionally very much similar. They talk to ACPI in same way. Only
 238         difference between them is the way they do frequency transitions.
 239         One uses MSRs and the other one uses IO ports. Functionaliy of
 240         speedstep_centrino with ACPI hooks is now merged into acpi-cpufreq.
 241         That means one common driver will support all Intel Enhanced Speedstep
 242         capable CPUs. That means less confusion over name of
 243         speedstep-centrino driver (with that driver supposed to be used on
 244         non-centrino platforms). That means less duplication of code and
 245         less maintenance effort and no possibility of these two drivers
 246         going out of sync.
 247         Current users of speedstep_centrino with ACPI hooks are requested to
 248         switch over to acpi-cpufreq driver. speedstep-centrino will continue
 249         to work using older non-ACPI static table based scheme even after this
 250         date.
 251
 252 Who:    Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 253
 254 ---------------------------
 255
 256 <<<<<<< test:Documentation/feature-removal-schedule.txt
 257 What:   ACPI hotkey driver (CONFIG_ACPI_HOTKEY)
 258 When:   2.6.21
 259 Why:    hotkey.c was an attempt to consolidate multiple drivers that use
 260         ACPI to implement hotkeys.  However, hotkeys are not documented
 261         in the ACPI specification, so the drivers used undocumented
 262         vendor-specific hooks and turned out to be more different than
 263         the same.
 264
 265         Further, the keys and the features supplied by each platform
 266         are different, so there will always be a need for
 267         platform-specific drivers.
 268
 269         So the new plan is to delete hotkey.c and instead, work on the
 270         platform specific drivers to try to make them look the same
 271         to the user when they supply the same features.
 272
 273         hotkey.c has always depended on CONFIG_EXPERIMENTAL
 274
 275 Who:    Len Brown <len.brown@intel.com>
 276
 277 ---------------------------
 278
 279 What:   /sys/firmware/acpi/namespace
 280 When:   2.6.21
 281 Why:    The ACPI namespace is effectively the symbol list for
 282         the BIOS.  The device names are completely arbitrary
 283         and have no place being exposed to user-space.
 284
 285         For those interested in the BIOS ACPI namespace,
 286         the BIOS can be extracted and disassembled with acpidump
 287         and iasl as documented in the pmtools package here:
 288         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 289 Who:    Len Brown <len.brown@intel.com>
 290
 291 ---------------------------
 292
 293 What:   ACPI procfs interface
 294 When:   July 2007
 295 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 296         in sysfs and the ACPI procfs interface should be removed.
 297 Who:    Zhang Rui <rui.zhang@intel.com>
 298
 299 ---------------------------
 300
 301 What:   /proc/acpi/button
 302 When:   August 2007
 303 Why:    /proc/acpi/button has been replaced by events to the input layer
 304         since 2.6.20.
 305 Who:    Len Brown <len.brown@intel.com>
 306
 307 ---------------------------
 308
 309 What:   JFFS (version 1)
 310 When:   2.6.21
 311 Why:    Unmaintained for years, superceded by JFFS2 for years.
 312 Who:    Jeff Garzik <jeff@garzik.org>
 313
 314 ---------------------------
 315
 316 What:   sk98lin network driver
 317 When:   July 2007
 318 Why:    In kernel tree version of driver is unmaintained. Sk98lin driver
 319         replaced by the skge driver.
 320 Who:    Stephen Hemminger <shemminger@osdl.org>
 321
 322 ---------------------------
 323
 324 What:   Compaq touchscreen device emulation
 325 When:   Oct 2007
 326 Files:  drivers/input/tsdev.c
 327 Why:    The code says it was obsolete when it was written in 2001.
 328         tslib is a userspace library which does anything tsdev can do and
 329         much more besides in userspace where this code belongs. There is no
 330         longer any need for tsdev and applications should have converted to
 331         use tslib by now.
 332         The name "tsdev" is also extremely confusing and lots of people have
 333         it loaded when they don't need/use it.
 334 Who:    Richard Purdie <rpurdie@rpsys.net>
 335
 336 ---------------------------