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 Check:  include/linux/video_decoder.h
  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 Check:  kernel_thread
  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:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 114         (temporary transition config option provided until then)
 115         The transition config option will also be removed at the same time.
 116 When:   before 2.6.19
 117 Why:    Unused symbols are both increasing the size of the kernel binary
 118         and are often a sign of "wrong API"
 119 Who:    Arjan van de Ven <arjan@linux.intel.com>
 120
 121 ---------------------------
 122
 123 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 124 When:   February 2008
 125 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 126 Why:    The USB subsystem has changed a lot over time, and it has been
 127         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 128         that operate as fast as the USB bus allows.  Because of this, the USB
 129         subsystem will not be allowing closed source kernel drivers to
 130         register with it, after this grace period is over.  If anyone needs
 131         any help in converting their closed source drivers over to use the
 132         userspace filesystems, please contact the
 133         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 134         there will be glad to help you out.
 135 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 136
 137 ---------------------------
 138
 139 What:   vm_ops.nopage
 140 When:   Soon, provided in-kernel callers have been converted
 141 Why:    This interface is replaced by vm_ops.fault, but it has been around
 142         forever, is used by a lot of drivers, and doesn't cost much to
 143         maintain.
 144 Who:    Nick Piggin <npiggin@suse.de>
 145
 146 ---------------------------
 147
 148 What:   Interrupt only SA_* flags
 149 When:   September 2007
 150 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 151         out of the signal namespace.
 152
 153 Who:    Thomas Gleixner <tglx@linutronix.de>
 154
 155 ---------------------------
 156
 157 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 158 When:   October 2008
 159 Why:    The stacking of class devices makes these values misleading and
 160         inconsistent.
 161         Class devices should not carry any of these properties, and bus
 162         devices have SUBSYTEM and DRIVER as a replacement.
 163 Who:    Kay Sievers <kay.sievers@suse.de>
 164
 165 ---------------------------
 166
 167 What:   i2c_adapter.list
 168 When:   July 2007
 169 Why:    Superfluous, this list duplicates the one maintained by the driver
 170         core.
 171 Who:    Jean Delvare <khali@linux-fr.org>,
 172         David Brownell <dbrownell@users.sourceforge.net>
 173
 174 ---------------------------
 175
 176 What:  drivers depending on OBSOLETE_OSS
 177 When:  options in 2.6.22, code in 2.6.24
 178 Why:   OSS drivers with ALSA replacements
 179 Who:   Adrian Bunk <bunk@stusta.de>
 180
 181 ---------------------------
 182
 183 What:   ACPI procfs interface
 184 When:   July 2008
 185 Why:    ACPI sysfs conversion should be finished by January 2008.
 186         ACPI procfs interface will be removed in July 2008 so that
 187         there is enough time for the user space to catch up.
 188 Who:    Zhang Rui <rui.zhang@intel.com>
 189
 190 ---------------------------
 191
 192 What:   /proc/acpi/button
 193 When:   August 2007
 194 Why:    /proc/acpi/button has been replaced by events to the input layer
 195         since 2.6.20.
 196 Who:    Len Brown <len.brown@intel.com>
 197
 198 ---------------------------
 199
 200 What:   Compaq touchscreen device emulation
 201 When:   Oct 2007
 202 Files:  drivers/input/tsdev.c
 203 Why:    The code says it was obsolete when it was written in 2001.
 204         tslib is a userspace library which does anything tsdev can do and
 205         much more besides in userspace where this code belongs. There is no
 206         longer any need for tsdev and applications should have converted to
 207         use tslib by now.
 208         The name "tsdev" is also extremely confusing and lots of people have
 209         it loaded when they don't need/use it.
 210 Who:    Richard Purdie <rpurdie@rpsys.net>
 211
 212 ---------------------------
 213
 214 What:   read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 215 When:   December 2007
 216 Why:    These functions are a leftover from 2.4 times. They have several
 217         problems:
 218         - Duplication of checks that are done in the device driver's
 219           interrupt handler
 220         - common I/O layer can't do device specific error recovery
 221         - device driver can't be notified for conditions happening during
 222           execution of the function
 223         Device drivers should issue the read device characteristics and read
 224         configuration data ccws and do the appropriate error handling
 225         themselves.
 226 Who:    Cornelia Huck <cornelia.huck@de.ibm.com>
 227
 228 ---------------------------
 229
 230 What:   i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
 231 When:   September 2007
 232 Why:    Obsolete. The new i2c-gpio driver replaces all hardware-specific
 233         I2C-over-GPIO drivers.
 234 Who:    Jean Delvare <khali@linux-fr.org>
 235
 236 ---------------------------
 237
 238 What:   'time' kernel boot parameter
 239 When:   January 2008
 240 Why:    replaced by 'printk.time=<value>' so that printk timestamps can be
 241         enabled or disabled as needed
 242 Who:    Randy Dunlap <randy.dunlap@oracle.com>
 243
 244 ---------------------------
 245
 246 What:  drivers depending on OSS_OBSOLETE
 247 When:  options in 2.6.23, code in 2.6.25
 248 Why:   obsolete OSS drivers
 249 Who:   Adrian Bunk <bunk@stusta.de>
 250
 251 ---------------------------
 252
 253 What: libata spindown skipping and warning
 254 When: Dec 2008
 255 Why:  Some halt(8) implementations synchronize caches for and spin
 256       down libata disks because libata didn't use to spin down disk on
 257       system halt (only synchronized caches).
 258       Spin down on system halt is now implemented.  sysfs node
 259       /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
 260       spin down support is available.
 261       Because issuing spin down command to an already spun down disk
 262       makes some disks spin up just to spin down again, libata tracks
 263       device spindown status to skip the extra spindown command and
 264       warn about it.
 265       This is to give userspace tools the time to get updated and will
 266       be removed after userspace is reasonably updated.
 267 Who:  Tejun Heo <htejun@gmail.com>
 268
 269 ---------------------------
 270
 271 What:   Legacy RTC drivers (under drivers/i2c/chips)
 272 When:   November 2007
 273 Why:    Obsolete. We have a RTC subsystem with better drivers.
 274 Who:    Jean Delvare <khali@linux-fr.org>
 275
 276 ---------------------------
 277
 278 What:   iptables SAME target
 279 When:   1.1. 2008
 280 Files:  net/ipv4/netfilter/ipt_SAME.c, include/linux/netfilter_ipv4/ipt_SAME.h
 281 Why:    Obsolete for multiple years now, NAT core provides the same behaviour.
 282         Unfixable broken wrt. 32/64 bit cleanness.
 283 Who:    Patrick McHardy <kaber@trash.net>
 284
 285 ---------------------------
 286
 287 What: The arch/ppc and include/asm-ppc directories
 288 When: Jun 2008
 289 Why:  The arch/powerpc tree is the merged architecture for ppc32 and ppc64
 290       platforms.  Currently there are efforts underway to port the remaining
 291       arch/ppc platforms to the merged tree.  New submissions to the arch/ppc
 292       tree have been frozen with the 2.6.22 kernel release and that tree will
 293       remain in bug-fix only mode until its scheduled removal.  Platforms
 294       that are not ported by June 2008 will be removed due to the lack of an
 295       interested maintainer.
 296 Who:  linuxppc-dev@ozlabs.org
 297
 298 ---------------------------
 299
 300 What:   mthca driver's MSI support
 301 When:   January 2008
 302 Files:  drivers/infiniband/hw/mthca/*.[ch]
 303 Why:    All mthca hardware also supports MSI-X, which provides
 304         strictly more functionality than MSI.  So there is no point in
 305         having both MSI-X and MSI support in the driver.
 306 Who:    Roland Dreier <rolandd@cisco.com>
 307
 308 ---------------------------