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