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:   MXSER
  10 When:   December 2007
  11 Why:    Old mxser driver is obsoleted by the mxser_new. Give it some time yet
  12         and remove it.
  13 Who:    Jiri Slaby <jirislaby@gmail.com>
  14
  15 ---------------------------
  16
  17 What:   V4L2 VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP
  18 When:   October 2007
  19 Why:    Broken attempt to set MPEG compression parameters. These ioctls are
  20         not able to implement the wide variety of parameters that can be set
  21         by hardware MPEG encoders. A new MPEG control mechanism was created
  22         in kernel 2.6.18 that replaces these ioctls. See the V4L2 specification
  23         (section 1.9: Extended controls) for more information on this topic.
  24 Who:    Hans Verkuil <hverkuil@xs4all.nl> and
  25         Mauro Carvalho Chehab <mchehab@infradead.org>
  26
  27 ---------------------------
  28
  29 What:   /sys/devices/.../power/state
  30         dev->power.power_state
  31         dpm_runtime_{suspend,resume)()
  32 When:   July 2007
  33 Why:    Broken design for runtime control over driver power states, confusing
  34         driver-internal runtime power management with:  mechanisms to support
  35         system-wide sleep state transitions; event codes that distinguish
  36         different phases of swsusp "sleep" transitions; and userspace policy
  37         inputs.  This framework was never widely used, and most attempts to
  38         use it were broken.  Drivers should instead be exposing domain-specific
  39         interfaces either to kernel or to userspace.
  40 Who:    Pavel Machek <pavel@suse.cz>
  41
  42 ---------------------------
  43
  44 What:   RAW driver (CONFIG_RAW_DRIVER)
  45 When:   December 2005
  46 Why:    declared obsolete since kernel 2.6.3
  47         O_DIRECT can be used instead
  48 Who:    Adrian Bunk <bunk@stusta.de>
  49
  50 ---------------------------
  51
  52 What:   old NCR53C9x driver
  53 When:   October 2007
  54 Why:    Replaced by the much better esp_scsi driver.  Actual low-level
  55         driver can be ported over almost trivially.
  56 Who:    David Miller <davem@davemloft.net>
  57         Christoph Hellwig <hch@lst.de>
  58
  59 ---------------------------
  60
  61 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  62 When:   December 2006
  63 Files:  include/linux/video_decoder.h
  64 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  65         series. The old API have lots of drawbacks and don't provide enough
  66         means to work with all video and audio standards. The newer API is
  67         already available on the main drivers and should be used instead.
  68         Newer drivers should use v4l_compat_translate_ioctl function to handle
  69         old calls, replacing to newer ones.
  70         Decoder iocts are using internally to allow video drivers to
  71         communicate with video decoders. This should also be improved to allow
  72         V4L2 calls being translated into compatible internal ioctls.
  73 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  74
  75 ---------------------------
  76
  77 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  78 When:   November 2005
  79 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  80 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  81         normal hotpluggable bus, and with it using the default kernel
  82         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  83         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  84         unnecessary, and makes further cleanups and integration of the
  85         PCMCIA subsystem into the Linux kernel device driver model more
  86         difficult. The features provided by cardmgr and cardctl are either
  87         handled by the kernel itself now or are available in the new
  88         pcmciautils package available at
  89         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  90 Who:    Dominik Brodowski <linux@brodo.de>
  91
  92 ---------------------------
  93
  94 What:   remove EXPORT_SYMBOL(kernel_thread)
  95 When:   August 2006
  96 Files:  arch/*/kernel/*_ksyms.c
  97 Funcs:  kernel_thread
  98 Why:    kernel_thread is a low-level implementation detail.  Drivers should
  99         use the <linux/kthread.h> API instead which shields them from
 100         implementation details and provides a higherlevel interface that
 101         prevents bugs and code duplication
 102 Who:    Christoph Hellwig <hch@lst.de>
 103
 104 ---------------------------
 105
 106 What:   CONFIG_FORCED_INLINING
 107 When:   June 2006
 108 Why:    Config option is there to see if gcc is good enough. (in january
 109         2006). If it is, the behavior should just be the default. If it's not,
 110         the option should just go away entirely.
 111 Who:    Arjan van de Ven
 112
 113 ---------------------------
 114
 115 What:   eepro100 network driver
 116 When:   January 2007
 117 Why:    replaced by the e100 driver
 118 Who:    Adrian Bunk <bunk@stusta.de>
 119
 120 ---------------------------
 121
 122 What:  drivers depending on OSS_OBSOLETE_DRIVER
 123 When:  options in 2.6.20, code in 2.6.22
 124 Why:   OSS drivers with ALSA replacements
 125 Who:   Adrian Bunk <bunk@stusta.de>
 126
 127 ---------------------------
 128
 129 What:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 130         (temporary transition config option provided until then)
 131         The transition config option will also be removed at the same time.
 132 When:   before 2.6.19
 133 Why:    Unused symbols are both increasing the size of the kernel binary
 134         and are often a sign of "wrong API"
 135 Who:    Arjan van de Ven <arjan@linux.intel.com>
 136
 137 ---------------------------
 138
 139 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 140 When:   February 2008
 141 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 142 Why:    The USB subsystem has changed a lot over time, and it has been
 143         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 144         that operate as fast as the USB bus allows.  Because of this, the USB
 145         subsystem will not be allowing closed source kernel drivers to
 146         register with it, after this grace period is over.  If anyone needs
 147         any help in converting their closed source drivers over to use the
 148         userspace filesystems, please contact the
 149         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 150         there will be glad to help you out.
 151 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 152
 153 ---------------------------
 154
 155 What:   Interrupt only SA_* flags
 156 When:   September 2007
 157 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 158         out of the signal namespace.
 159
 160 Who:    Thomas Gleixner <tglx@linutronix.de>
 161
 162 ---------------------------
 163
 164 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 165 When:   October 2008
 166 Why:    The stacking of class devices makes these values misleading and
 167         inconsistent.
 168         Class devices should not carry any of these properties, and bus
 169         devices have SUBSYTEM and DRIVER as a replacement.
 170 Who:    Kay Sievers <kay.sievers@suse.de>
 171
 172 ---------------------------
 173
 174 What:   i2c-isa
 175 When:   December 2006
 176 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 177         model. Drivers relying on it are better implemented as platform
 178         drivers.
 179 Who:    Jean Delvare <khali@linux-fr.org>
 180
 181 ---------------------------
 182
 183 What:   i2c_adapter.list
 184 When:   July 2007
 185 Why:    Superfluous, this list duplicates the one maintained by the driver
 186         core.
 187 Who:    Jean Delvare <khali@linux-fr.org>,
 188         David Brownell <dbrownell@users.sourceforge.net>
 189
 190 ---------------------------
 191
 192 What:  drivers depending on OBSOLETE_OSS
 193 When:  options in 2.6.22, code in 2.6.24
 194 Why:   OSS drivers with ALSA replacements
 195 Who:   Adrian Bunk <bunk@stusta.de>
 196
 197 ---------------------------
 198
 199 What:   ACPI hooks (X86_SPEEDSTEP_CENTRINO_ACPI) in speedstep-centrino driver
 200 When:   December 2006
 201 Why:    Speedstep-centrino driver with ACPI hooks and acpi-cpufreq driver are
 202         functionally very much similar. They talk to ACPI in same way. Only
 203         difference between them is the way they do frequency transitions.
 204         One uses MSRs and the other one uses IO ports. Functionaliy of
 205         speedstep_centrino with ACPI hooks is now merged into acpi-cpufreq.
 206         That means one common driver will support all Intel Enhanced Speedstep
 207         capable CPUs. That means less confusion over name of
 208         speedstep-centrino driver (with that driver supposed to be used on
 209         non-centrino platforms). That means less duplication of code and
 210         less maintenance effort and no possibility of these two drivers
 211         going out of sync.
 212         Current users of speedstep_centrino with ACPI hooks are requested to
 213         switch over to acpi-cpufreq driver. speedstep-centrino will continue
 214         to work using older non-ACPI static table based scheme even after this
 215         date.
 216
 217 Who:    Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
 218
 219 ---------------------------
 220
 221 What:   /sys/firmware/acpi/namespace
 222 When:   2.6.21
 223 Why:    The ACPI namespace is effectively the symbol list for
 224         the BIOS.  The device names are completely arbitrary
 225         and have no place being exposed to user-space.
 226
 227         For those interested in the BIOS ACPI namespace,
 228         the BIOS can be extracted and disassembled with acpidump
 229         and iasl as documented in the pmtools package here:
 230         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 231 Who:    Len Brown <len.brown@intel.com>
 232
 233 ---------------------------
 234
 235 What:   ACPI procfs interface
 236 When:   July 2007
 237 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 238         in sysfs and the ACPI procfs interface should be removed.
 239 Who:    Zhang Rui <rui.zhang@intel.com>
 240
 241 ---------------------------
 242
 243 What:   /proc/acpi/button
 244 When:   August 2007
 245 Why:    /proc/acpi/button has been replaced by events to the input layer
 246         since 2.6.20.
 247 Who:    Len Brown <len.brown@intel.com>
 248
 249 ---------------------------
 250
 251 What:   Compaq touchscreen device emulation
 252 When:   Oct 2007
 253 Files:  drivers/input/tsdev.c
 254 Why:    The code says it was obsolete when it was written in 2001.
 255         tslib is a userspace library which does anything tsdev can do and
 256         much more besides in userspace where this code belongs. There is no
 257         longer any need for tsdev and applications should have converted to
 258         use tslib by now.
 259         The name "tsdev" is also extremely confusing and lots of people have
 260         it loaded when they don't need/use it.
 261 Who:    Richard Purdie <rpurdie@rpsys.net>
 262
 263 ---------------------------
 264
 265 What:   read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 266 When:   December 2007
 267 Why:    These functions are a leftover from 2.4 times. They have several
 268         problems:
 269         - Duplication of checks that are done in the device driver's
 270           interrupt handler
 271         - common I/O layer can't do device specific error recovery
 272         - device driver can't be notified for conditions happening during
 273           execution of the function
 274         Device drivers should issue the read device characteristics and read
 275         configuration data ccws and do the appropriate error handling
 276         themselves.
 277 Who:    Cornelia Huck <cornelia.huck@de.ibm.com>
 278
 279 ---------------------------
 280
 281 What:   i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
 282 When:   September 2007
 283 Why:    Obsolete. The new i2c-gpio driver replaces all hardware-specific
 284         I2C-over-GPIO drivers.
 285 Who:    Jean Delvare <khali@linux-fr.org>
 286
 287 ---------------------------
 288
 289 What:  drivers depending on OSS_OBSOLETE
 290 When:  options in 2.6.23, code in 2.6.25
 291 Why:   obsolete OSS drivers
 292 Who:   Adrian Bunk <bunk@stusta.de>
 293
 294 ---------------------------
 295
 296 What: libata spindown skipping and warning
 297 When: Dec 2008
 298 Why:  Some halt(8) implementations synchronize caches for and spin
 299       down libata disks because libata didn't use to spin down disk on
 300       system halt (only synchronized caches).
 301       Spin down on system halt is now implemented.  sysfs node
 302       /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
 303       spin down support is available.
 304       Because issuing spin down command to an already spun down disk
 305       makes some disks spin up just to spin down again, libata tracks
 306       device spindown status to skip the extra spindown command and
 307       warn about it.
 308       This is to give userspace tools the time to get updated and will
 309       be removed after userspace is reasonably updated.
 310 Who:  Tejun Heo <htejun@gmail.com>
 311
 312 ---------------------------
 313
 314 What:   iptables SAME target
 315 When:   1.1. 2008
 316 Files:  net/ipv4/netfilter/ipt_SAME.c, include/linux/netfilter_ipv4/ipt_SAME.h
 317 Why:    Obsolete for multiple years now, NAT core provides the same behaviour.
 318         Unfixable broken wrt. 32/64 bit cleanness.
 319 Who:    Patrick McHardy <kaber@trash.net>
 320
 321 ---------------------------