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:   Interrupt only SA_* flags
 139 When:   September 2007
 140 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 141         out of the signal namespace.
 142
 143 Who:    Thomas Gleixner <tglx@linutronix.de>
 144
 145 ---------------------------
 146
 147 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 148 When:   October 2008
 149 Why:    The stacking of class devices makes these values misleading and
 150         inconsistent.
 151         Class devices should not carry any of these properties, and bus
 152         devices have SUBSYTEM and DRIVER as a replacement.
 153 Who:    Kay Sievers <kay.sievers@suse.de>
 154
 155 ---------------------------
 156
 157 What:   i2c-isa
 158 When:   December 2006
 159 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 160         model. Drivers relying on it are better implemented as platform
 161         drivers.
 162 Who:    Jean Delvare <khali@linux-fr.org>
 163
 164 ---------------------------
 165
 166 What:   i2c_adapter.list
 167 When:   July 2007
 168 Why:    Superfluous, this list duplicates the one maintained by the driver
 169         core.
 170 Who:    Jean Delvare <khali@linux-fr.org>,
 171         David Brownell <dbrownell@users.sourceforge.net>
 172
 173 ---------------------------
 174
 175 What:  drivers depending on OBSOLETE_OSS
 176 When:  options in 2.6.22, code in 2.6.24
 177 Why:   OSS drivers with ALSA replacements
 178 Who:   Adrian Bunk <bunk@stusta.de>
 179
 180 ---------------------------
 181
 182 What:   /sys/firmware/acpi/namespace
 183 When:   2.6.21
 184 Why:    The ACPI namespace is effectively the symbol list for
 185         the BIOS.  The device names are completely arbitrary
 186         and have no place being exposed to user-space.
 187
 188         For those interested in the BIOS ACPI namespace,
 189         the BIOS can be extracted and disassembled with acpidump
 190         and iasl as documented in the pmtools package here:
 191         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 192 Who:    Len Brown <len.brown@intel.com>
 193
 194 ---------------------------
 195
 196 What:   ACPI procfs interface
 197 When:   July 2007
 198 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 199         in sysfs and the ACPI procfs interface should be removed.
 200 Who:    Zhang Rui <rui.zhang@intel.com>
 201
 202 ---------------------------
 203
 204 What:   /proc/acpi/button
 205 When:   August 2007
 206 Why:    /proc/acpi/button has been replaced by events to the input layer
 207         since 2.6.20.
 208 Who:    Len Brown <len.brown@intel.com>
 209
 210 ---------------------------
 211
 212 What:   Compaq touchscreen device emulation
 213 When:   Oct 2007
 214 Files:  drivers/input/tsdev.c
 215 Why:    The code says it was obsolete when it was written in 2001.
 216         tslib is a userspace library which does anything tsdev can do and
 217         much more besides in userspace where this code belongs. There is no
 218         longer any need for tsdev and applications should have converted to
 219         use tslib by now.
 220         The name "tsdev" is also extremely confusing and lots of people have
 221         it loaded when they don't need/use it.
 222 Who:    Richard Purdie <rpurdie@rpsys.net>
 223
 224 ---------------------------
 225
 226 What:   read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 227 When:   December 2007
 228 Why:    These functions are a leftover from 2.4 times. They have several
 229         problems:
 230         - Duplication of checks that are done in the device driver's
 231           interrupt handler
 232         - common I/O layer can't do device specific error recovery
 233         - device driver can't be notified for conditions happening during
 234           execution of the function
 235         Device drivers should issue the read device characteristics and read
 236         configuration data ccws and do the appropriate error handling
 237         themselves.
 238 Who:    Cornelia Huck <cornelia.huck@de.ibm.com>
 239
 240 ---------------------------
 241
 242 What:   i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
 243 When:   September 2007
 244 Why:    Obsolete. The new i2c-gpio driver replaces all hardware-specific
 245         I2C-over-GPIO drivers.
 246 Who:    Jean Delvare <khali@linux-fr.org>
 247
 248 ---------------------------
 249
 250 What:   'time' kernel boot parameter
 251 When:   January 2008
 252 Why:    replaced by 'printk.time=<value>' so that printk timestamps can be
 253         enabled or disabled as needed
 254 Who:    Randy Dunlap <randy.dunlap@oracle.com>
 255
 256 ---------------------------
 257
 258 What:  drivers depending on OSS_OBSOLETE
 259 When:  options in 2.6.23, code in 2.6.25
 260 Why:   obsolete OSS drivers
 261 Who:   Adrian Bunk <bunk@stusta.de>
 262
 263 ---------------------------
 264
 265 What: libata spindown skipping and warning
 266 When: Dec 2008
 267 Why:  Some halt(8) implementations synchronize caches for and spin
 268       down libata disks because libata didn't use to spin down disk on
 269       system halt (only synchronized caches).
 270       Spin down on system halt is now implemented.  sysfs node
 271       /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
 272       spin down support is available.
 273       Because issuing spin down command to an already spun down disk
 274       makes some disks spin up just to spin down again, libata tracks
 275       device spindown status to skip the extra spindown command and
 276       warn about it.
 277       This is to give userspace tools the time to get updated and will
 278       be removed after userspace is reasonably updated.
 279 Who:  Tejun Heo <htejun@gmail.com>
 280
 281 ---------------------------
 282
 283 What:   Legacy RTC drivers (under drivers/i2c/chips)
 284 When:   November 2007
 285 Why:    Obsolete. We have a RTC subsystem with better drivers.
 286 Who:    Jean Delvare <khali@linux-fr.org>
 287
 288 ---------------------------
 289
 290 What:   iptables SAME target
 291 When:   1.1. 2008
 292 Files:  net/ipv4/netfilter/ipt_SAME.c, include/linux/netfilter_ipv4/ipt_SAME.h
 293 Why:    Obsolete for multiple years now, NAT core provides the same behaviour.
 294         Unfixable broken wrt. 32/64 bit cleanness.
 295 Who:    Patrick McHardy <kaber@trash.net>
 296
 297 ---------------------------
 298
 299 What: The arch/ppc and include/asm-ppc directories
 300 When: Jun 2008
 301 Why:  The arch/powerpc tree is the merged architecture for ppc32 and ppc64
 302       platforms.  Currently there are efforts underway to port the remaining
 303       arch/ppc platforms to the merged tree.  New submissions to the arch/ppc
 304       tree have been frozen with the 2.6.22 kernel release and that tree will
 305       remain in bug-fix only mode until its scheduled removal.  Platforms
 306       that are not ported by June 2008 will be removed due to the lack of an
 307       interested maintainer.
 308 Who:  linuxppc-dev@ozlabs.org
 309
 310 ---------------------------
 311
 312 What:   mthca driver's MSI support
 313 When:   January 2008
 314 Files:  drivers/infiniband/hw/mthca/*.[ch]
 315 Why:    All mthca hardware also supports MSI-X, which provides
 316         strictly more functionality than MSI.  So there is no point in
 317         having both MSI-X and MSI support in the driver.
 318 Who:    Roland Dreier <rolandd@cisco.com>
 319
 320 ---------------------------