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:   dev->power.power_state
  30 When:   July 2007
  31 Why:    Broken design for runtime control over driver power states, confusing
  32         driver-internal runtime power management with:  mechanisms to support
  33         system-wide sleep state transitions; event codes that distinguish
  34         different phases of swsusp "sleep" transitions; and userspace policy
  35         inputs.  This framework was never widely used, and most attempts to
  36         use it were broken.  Drivers should instead be exposing domain-specific
  37         interfaces either to kernel or to userspace.
  38 Who:    Pavel Machek <pavel@suse.cz>
  39
  40 ---------------------------
  41
  42 What:   old NCR53C9x driver
  43 When:   October 2007
  44 Why:    Replaced by the much better esp_scsi driver.  Actual low-level
  45         driver can be ported over almost trivially.
  46 Who:    David Miller <davem@davemloft.net>
  47         Christoph Hellwig <hch@lst.de>
  48
  49 ---------------------------
  50
  51 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  52 When:   December 2006
  53 Files:  include/linux/video_decoder.h
  54 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  55         series. The old API have lots of drawbacks and don't provide enough
  56         means to work with all video and audio standards. The newer API is
  57         already available on the main drivers and should be used instead.
  58         Newer drivers should use v4l_compat_translate_ioctl function to handle
  59         old calls, replacing to newer ones.
  60         Decoder iocts are using internally to allow video drivers to
  61         communicate with video decoders. This should also be improved to allow
  62         V4L2 calls being translated into compatible internal ioctls.
  63 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  64
  65 ---------------------------
  66
  67 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  68 When:   November 2005
  69 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  70 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  71         normal hotpluggable bus, and with it using the default kernel
  72         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  73         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  74         unnecessary, and makes further cleanups and integration of the
  75         PCMCIA subsystem into the Linux kernel device driver model more
  76         difficult. The features provided by cardmgr and cardctl are either
  77         handled by the kernel itself now or are available in the new
  78         pcmciautils package available at
  79         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  80 Who:    Dominik Brodowski <linux@brodo.de>
  81
  82 ---------------------------
  83
  84 What:   remove EXPORT_SYMBOL(kernel_thread)
  85 When:   August 2006
  86 Files:  arch/*/kernel/*_ksyms.c
  87 Funcs:  kernel_thread
  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:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 113         (temporary transition config option provided until then)
 114         The transition config option will also be removed at the same time.
 115 When:   before 2.6.19
 116 Why:    Unused symbols are both increasing the size of the kernel binary
 117         and are often a sign of "wrong API"
 118 Who:    Arjan van de Ven <arjan@linux.intel.com>
 119
 120 ---------------------------
 121
 122 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 123 When:   February 2008
 124 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 125 Why:    The USB subsystem has changed a lot over time, and it has been
 126         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 127         that operate as fast as the USB bus allows.  Because of this, the USB
 128         subsystem will not be allowing closed source kernel drivers to
 129         register with it, after this grace period is over.  If anyone needs
 130         any help in converting their closed source drivers over to use the
 131         userspace filesystems, please contact the
 132         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 133         there will be glad to help you out.
 134 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 135
 136 ---------------------------
 137
 138 What:   vm_ops.nopage
 139 When:   Soon, provided in-kernel callers have been converted
 140 Why:    This interface is replaced by vm_ops.fault, but it has been around
 141         forever, is used by a lot of drivers, and doesn't cost much to
 142         maintain.
 143 Who:    Nick Piggin <npiggin@suse.de>
 144
 145 ---------------------------
 146
 147 What:   Interrupt only SA_* flags
 148 When:   September 2007
 149 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 150         out of the signal namespace.
 151
 152 Who:    Thomas Gleixner <tglx@linutronix.de>
 153
 154 ---------------------------
 155
 156 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 157 When:   October 2008
 158 Why:    The stacking of class devices makes these values misleading and
 159         inconsistent.
 160         Class devices should not carry any of these properties, and bus
 161         devices have SUBSYTEM and DRIVER as a replacement.
 162 Who:    Kay Sievers <kay.sievers@suse.de>
 163
 164 ---------------------------
 165
 166 What:   i2c-isa
 167 When:   December 2006
 168 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 169         model. Drivers relying on it are better implemented as platform
 170         drivers.
 171 Who:    Jean Delvare <khali@linux-fr.org>
 172
 173 ---------------------------
 174
 175 What:   i2c_adapter.list
 176 When:   July 2007
 177 Why:    Superfluous, this list duplicates the one maintained by the driver
 178         core.
 179 Who:    Jean Delvare <khali@linux-fr.org>,
 180         David Brownell <dbrownell@users.sourceforge.net>
 181
 182 ---------------------------
 183
 184 What:  drivers depending on OBSOLETE_OSS
 185 When:  options in 2.6.22, code in 2.6.24
 186 Why:   OSS drivers with ALSA replacements
 187 Who:   Adrian Bunk <bunk@stusta.de>
 188
 189 ---------------------------
 190
 191 What:   /sys/firmware/acpi/namespace
 192 When:   2.6.21
 193 Why:    The ACPI namespace is effectively the symbol list for
 194         the BIOS.  The device names are completely arbitrary
 195         and have no place being exposed to user-space.
 196
 197         For those interested in the BIOS ACPI namespace,
 198         the BIOS can be extracted and disassembled with acpidump
 199         and iasl as documented in the pmtools package here:
 200         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 201 Who:    Len Brown <len.brown@intel.com>
 202
 203 ---------------------------
 204
 205 What:   ACPI procfs interface
 206 When:   July 2007
 207 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 208         in sysfs and the ACPI procfs interface should be removed.
 209 Who:    Zhang Rui <rui.zhang@intel.com>
 210
 211 ---------------------------
 212
 213 What:   /proc/acpi/button
 214 When:   August 2007
 215 Why:    /proc/acpi/button has been replaced by events to the input layer
 216         since 2.6.20.
 217 Who:    Len Brown <len.brown@intel.com>
 218
 219 ---------------------------
 220
 221 What:   Compaq touchscreen device emulation
 222 When:   Oct 2007
 223 Files:  drivers/input/tsdev.c
 224 Why:    The code says it was obsolete when it was written in 2001.
 225         tslib is a userspace library which does anything tsdev can do and
 226         much more besides in userspace where this code belongs. There is no
 227         longer any need for tsdev and applications should have converted to
 228         use tslib by now.
 229         The name "tsdev" is also extremely confusing and lots of people have
 230         it loaded when they don't need/use it.
 231 Who:    Richard Purdie <rpurdie@rpsys.net>
 232
 233 ---------------------------
 234
 235 What:   read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 236 When:   December 2007
 237 Why:    These functions are a leftover from 2.4 times. They have several
 238         problems:
 239         - Duplication of checks that are done in the device driver's
 240           interrupt handler
 241         - common I/O layer can't do device specific error recovery
 242         - device driver can't be notified for conditions happening during
 243           execution of the function
 244         Device drivers should issue the read device characteristics and read
 245         configuration data ccws and do the appropriate error handling
 246         themselves.
 247 Who:    Cornelia Huck <cornelia.huck@de.ibm.com>
 248
 249 ---------------------------
 250
 251 What:   i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
 252 When:   September 2007
 253 Why:    Obsolete. The new i2c-gpio driver replaces all hardware-specific
 254         I2C-over-GPIO drivers.
 255 Who:    Jean Delvare <khali@linux-fr.org>
 256
 257 ---------------------------
 258
 259 What:   'time' kernel boot parameter
 260 When:   January 2008
 261 Why:    replaced by 'printk.time=<value>' so that printk timestamps can be
 262         enabled or disabled as needed
 263 Who:    Randy Dunlap <randy.dunlap@oracle.com>
 264
 265 ---------------------------
 266
 267 What:  drivers depending on OSS_OBSOLETE
 268 When:  options in 2.6.23, code in 2.6.25
 269 Why:   obsolete OSS drivers
 270 Who:   Adrian Bunk <bunk@stusta.de>
 271
 272 ---------------------------
 273
 274 What: libata spindown skipping and warning
 275 When: Dec 2008
 276 Why:  Some halt(8) implementations synchronize caches for and spin
 277       down libata disks because libata didn't use to spin down disk on
 278       system halt (only synchronized caches).
 279       Spin down on system halt is now implemented.  sysfs node
 280       /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
 281       spin down support is available.
 282       Because issuing spin down command to an already spun down disk
 283       makes some disks spin up just to spin down again, libata tracks
 284       device spindown status to skip the extra spindown command and
 285       warn about it.
 286       This is to give userspace tools the time to get updated and will
 287       be removed after userspace is reasonably updated.
 288 Who:  Tejun Heo <htejun@gmail.com>
 289
 290 ---------------------------
 291
 292 What:   Legacy RTC drivers (under drivers/i2c/chips)
 293 When:   November 2007
 294 Why:    Obsolete. We have a RTC subsystem with better drivers.
 295 Who:    Jean Delvare <khali@linux-fr.org>
 296
 297 ---------------------------
 298
 299 What:   iptables SAME target
 300 When:   1.1. 2008
 301 Files:  net/ipv4/netfilter/ipt_SAME.c, include/linux/netfilter_ipv4/ipt_SAME.h
 302 Why:    Obsolete for multiple years now, NAT core provides the same behaviour.
 303         Unfixable broken wrt. 32/64 bit cleanness.
 304 Who:    Patrick McHardy <kaber@trash.net>
 305
 306 ---------------------------
 307
 308 What: The arch/ppc and include/asm-ppc directories
 309 When: Jun 2008
 310 Why:  The arch/powerpc tree is the merged architecture for ppc32 and ppc64
 311       platforms.  Currently there are efforts underway to port the remaining
 312       arch/ppc platforms to the merged tree.  New submissions to the arch/ppc
 313       tree have been frozen with the 2.6.22 kernel release and that tree will
 314       remain in bug-fix only mode until its scheduled removal.  Platforms
 315       that are not ported by June 2008 will be removed due to the lack of an
 316       interested maintainer.
 317 Who:  linuxppc-dev@ozlabs.org
 318
 319 ---------------------------
 320
 321 What:   mthca driver's MSI support
 322 When:   January 2008
 323 Files:  drivers/infiniband/hw/mthca/*.[ch]
 324 Why:    All mthca hardware also supports MSI-X, which provides
 325         strictly more functionality than MSI.  So there is no point in
 326         having both MSI-X and MSI support in the driver.
 327 Who:    Roland Dreier <rolandd@cisco.com>
 328
 329 ---------------------------