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:   drivers that were depending on OBSOLETE_OSS_DRIVER
  33         (config options already removed)
  34 When:   before 2.6.19
  35 Why:    OSS drivers with ALSA replacements
  36 Who:    Adrian Bunk <bunk@stusta.de>
  37
  38 ---------------------------
  39
  40 What:   raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  41 When:   November 2006
  42 Why:    Deprecated in favour of the new ioctl-based rawiso interface, which is
  43         more efficient.  You should really be using libraw1394 for raw1394
  44         access anyway.
  45 Who:    Jody McIntyre <scjody@modernduck.com>
  46
  47 ---------------------------
  48
  49 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  50 When:   December 2006
  51 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  52         series. The old API have lots of drawbacks and don't provide enough
  53         means to work with all video and audio standards. The newer API is
  54         already available on the main drivers and should be used instead.
  55         Newer drivers should use v4l_compat_translate_ioctl function to handle
  56         old calls, replacing to newer ones.
  57         Decoder iocts are using internally to allow video drivers to
  58         communicate with video decoders. This should also be improved to allow
  59         V4L2 calls being translated into compatible internal ioctls.
  60 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  61
  62 ---------------------------
  63
  64 What:   sys_sysctl
  65 When:   January 2007
  66 Why:    The same information is available through /proc/sys and that is the
  67         interface user space prefers to use. And there do not appear to be
  68         any existing user in user space of sys_sysctl.  The additional
  69         maintenance overhead of keeping a set of binary names gets
  70         in the way of doing a good job of maintaining this interface.
  71
  72 Who:    Eric Biederman <ebiederm@xmission.com>
  73
  74 ---------------------------
  75
  76 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  77 When:   November 2005
  78 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  79 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  80         normal hotpluggable bus, and with it using the default kernel
  81         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  82         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  83         unnecessary, and makes further cleanups and integration of the
  84         PCMCIA subsystem into the Linux kernel device driver model more
  85         difficult. The features provided by cardmgr and cardctl are either
  86         handled by the kernel itself now or are available in the new
  87         pcmciautils package available at
  88         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  89 Who:    Dominik Brodowski <linux@brodo.de>
  90
  91 ---------------------------
  92
  93 What:   ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
  94 When:   December 2005
  95 Why:    This interface has been obsoleted by the new layer3-independent
  96         "nfnetlink_queue".  The Kernel interface is compatible, so the old
  97         ip[6]tables "QUEUE" targets still work and will transparently handle
  98         all packets into nfnetlink queue number 0.  Userspace users will have
  99         to link against API-compatible library on top of libnfnetlink_queue
 100         instead of the current 'libipq'.
 101 Who:    Harald Welte <laforge@netfilter.org>
 102
 103 ---------------------------
 104
 105 What:   remove EXPORT_SYMBOL(kernel_thread)
 106 When:   August 2006
 107 Files:  arch/*/kernel/*_ksyms.c
 108 Why:    kernel_thread is a low-level implementation detail.  Drivers should
 109         use the <linux/kthread.h> API instead which shields them from
 110         implementation details and provides a higherlevel interface that
 111         prevents bugs and code duplication
 112 Who:    Christoph Hellwig <hch@lst.de>
 113
 114 ---------------------------
 115
 116 What:   CONFIG_FORCED_INLINING
 117 When:   June 2006
 118 Why:    Config option is there to see if gcc is good enough. (in january
 119         2006). If it is, the behavior should just be the default. If it's not,
 120         the option should just go away entirely.
 121 Who:    Arjan van de Ven
 122
 123 ---------------------------
 124
 125 What:   eepro100 network driver
 126 When:   January 2007
 127 Why:    replaced by the e100 driver
 128 Who:    Adrian Bunk <bunk@stusta.de>
 129
 130 ---------------------------
 131
 132 What:  drivers depending on OSS_OBSOLETE_DRIVER
 133 When:  options in 2.6.20, code in 2.6.22
 134 Why:   OSS drivers with ALSA replacements
 135 Who:   Adrian Bunk <bunk@stusta.de>
 136
 137 ---------------------------
 138
 139 What:   pci_module_init(driver)
 140 When:   January 2007
 141 Why:    Is replaced by pci_register_driver(pci_driver).
 142 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 143
 144 ---------------------------
 145
 146 What:   Usage of invalid timevals in setitimer
 147 When:   March 2007
 148 Why:    POSIX requires to validate timevals in the setitimer call. This
 149         was never done by Linux. The invalid (e.g. negative timevals) were
 150         silently converted to more or less random timeouts and intervals.
 151         Until the removal a per boot limited number of warnings is printed
 152         and the timevals are sanitized.
 153
 154 Who:    Thomas Gleixner <tglx@linutronix.de>
 155
 156 ---------------------------
 157
 158 What:   I2C interface of the it87 driver
 159 When:   January 2007
 160 Why:    The ISA interface is faster and should be always available. The I2C
 161         probing is also known to cause trouble in at least one case (see
 162         bug #5889.)
 163 Who:    Jean Delvare <khali@linux-fr.org>
 164
 165 ---------------------------
 166
 167 What:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 168         (temporary transition config option provided until then)
 169         The transition config option will also be removed at the same time.
 170 When:   before 2.6.19
 171 Why:    Unused symbols are both increasing the size of the kernel binary
 172         and are often a sign of "wrong API"
 173 Who:    Arjan van de Ven <arjan@linux.intel.com>
 174
 175 ---------------------------
 176
 177 What:   mount/umount uevents
 178 When:   February 2007
 179 Why:    These events are not correct, and do not properly let userspace know
 180         when a file system has been mounted or unmounted.  Userspace should
 181         poll the /proc/mounts file instead to detect this properly.
 182 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 183
 184 ---------------------------
 185
 186 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 187 When:   Febuary 2008
 188 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 189 Why:    The USB subsystem has changed a lot over time, and it has been
 190         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 191         that operate as fast as the USB bus allows.  Because of this, the USB
 192         subsystem will not be allowing closed source kernel drivers to
 193         register with it, after this grace period is over.  If anyone needs
 194         any help in converting their closed source drivers over to use the
 195         userspace filesystems, please contact the
 196         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 197         there will be glad to help you out.
 198 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 199
 200 ---------------------------
 201
 202 What:   find_trylock_page
 203 When:   January 2007
 204 Why:    The interface no longer has any callers left in the kernel. It
 205         is an odd interface (compared with other find_*_page functions), in
 206         that it does not take a refcount to the page, only the page lock.
 207         It should be replaced with find_get_page or find_lock_page if possible.
 208         This feature removal can be reevaluated if users of the interface
 209         cannot cleanly use something else.
 210 Who:    Nick Piggin <npiggin@suse.de>
 211
 212 ---------------------------
 213
 214 What:   Support for the Momentum / PMC-Sierra Jaguar ATX evaluation board
 215 When:   September 2006
 216 Why:    Does no longer build since quite some time, and was never popular,
 217         due to the platform being replaced by successor models.  Apparently
 218         no user base left.  It also is one of the last users of
 219         WANT_PAGE_VIRTUAL.
 220 Who:    Ralf Baechle <ralf@linux-mips.org>
 221
 222 ---------------------------
 223
 224 What:   Support for the Momentum Ocelot, Ocelot 3, Ocelot C and Ocelot G
 225 When:   September 2006
 226 Why:    Some do no longer build and apparently there is no user base left
 227         for these platforms.
 228 Who:    Ralf Baechle <ralf@linux-mips.org>
 229
 230 ---------------------------
 231
 232 What:   Support for MIPS Technologies' Altas and SEAD evaluation board
 233 When:   September 2006
 234 Why:    Some do no longer build and apparently there is no user base left
 235         for these platforms.  Hardware out of production since several years.
 236 Who:    Ralf Baechle <ralf@linux-mips.org>
 237
 238 ---------------------------
 239
 240 What:   Support for the IT8172-based platforms, ITE 8172G and Globespan IVR
 241 When:   September 2006
 242 Why:    Code does no longer build since at least 2.6.0,  apparently there is
 243         no user base left for these platforms.  Hardware out of production
 244         since several years and hardly a trace of the manufacturer left on
 245         the net.
 246 Who:    Ralf Baechle <ralf@linux-mips.org>
 247
 248 ---------------------------
 249
 250 What:   Interrupt only SA_* flags
 251 When:   Januar 2007
 252 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 253         out of the signal namespace.
 254
 255 Who:    Thomas Gleixner <tglx@linutronix.de>
 256
 257 ---------------------------
 258
 259 What:   i2c-ite and i2c-algo-ite drivers
 260 When:   September 2006
 261 Why:    These drivers never compiled since they were added to the kernel
 262         tree 5 years ago. This feature removal can be reevaluated if
 263         someone shows interest in the drivers, fixes them and takes over
 264         maintenance.
 265         http://marc.theaimsgroup.com/?l=linux-mips&m=115040510817448
 266 Who:    Jean Delvare <khali@linux-fr.org>
 267
 268 ---------------------------
 269
 270 What:   Bridge netfilter deferred IPv4/IPv6 output hook calling
 271 When:   January 2007
 272 Why:    The deferred output hooks are a layering violation causing unusual
 273         and broken behaviour on bridge devices. Examples of things they
 274         break include QoS classifation using the MARK or CLASSIFY targets,
 275         the IPsec policy match and connection tracking with VLANs on a
 276         bridge. Their only use is to enable bridge output port filtering
 277         within iptables with the physdev match, which can also be done by
 278         combining iptables and ebtables using netfilter marks. Until it
 279         will get removed the hook deferral is disabled by default and is
 280         only enabled when needed.
 281
 282 Who:    Patrick McHardy <kaber@trash.net>
 283
 284 ---------------------------
 285
 286 What:   frame diverter
 287 When:   November 2006
 288 Why:    The frame diverter is included in most distribution kernels, but is
 289         broken. It does not correctly handle many things:
 290         - IPV6
 291         - non-linear skb's
 292         - network device RCU on removal
 293         - input frames not correctly checked for protocol errors
 294         It also adds allocation overhead even if not enabled.
 295         It is not clear if anyone is still using it.
 296 Who:    Stephen Hemminger <shemminger@osdl.org>
 297
 298 ---------------------------
 299
 300
 301 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 302 When:   Oktober 2008
 303 Why:    The stacking of class devices makes these values misleading and
 304         inconsistent.
 305         Class devices should not carry any of these properties, and bus
 306         devices have SUBSYTEM and DRIVER as a replacement.
 307 Who:    Kay Sievers <kay.sievers@suse.de>
 308
 309 ---------------------------
 310
 311 What:   i2c-isa
 312 When:   December 2006
 313 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 314         model. Drivers relying on it are better implemented as platform
 315         drivers.
 316 Who:    Jean Delvare <khali@linux-fr.org>
 317
 318 ---------------------------
 319
 320 What:   ftape
 321 When:   2.6.20
 322 Why:    Orphaned for ages.  SMP bugs long unfixed.  Few users left
 323         in the world.
 324 Who:    Jeff Garzik <jeff@garzik.org>
 325
 326 ---------------------------