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:   devfs
  10 When:   July 2005
  11 Files:  fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
  12         function calls throughout the kernel tree
  13 Why:    It has been unmaintained for a number of years, has unfixable
  14         races, contains a naming policy within the kernel that is
  15         against the LSB, and can be replaced by using udev.
  16 Who:    Greg Kroah-Hartman <greg@kroah.com>
  17
  18 ---------------------------
  19
  20 What:   RAW driver (CONFIG_RAW_DRIVER)
  21 When:   December 2005
  22 Why:    declared obsolete since kernel 2.6.3
  23         O_DIRECT can be used instead
  24 Who:    Adrian Bunk <bunk@stusta.de>
  25
  26 ---------------------------
  27
  28 What:   drivers depending on OBSOLETE_OSS_DRIVER
  29 When:   January 2006
  30 Why:    OSS drivers with ALSA replacements
  31 Who:    Adrian Bunk <bunk@stusta.de>
  32
  33 ---------------------------
  34
  35 What:   RCU API moves to EXPORT_SYMBOL_GPL
  36 When:   April 2006
  37 Files:  include/linux/rcupdate.h, kernel/rcupdate.c
  38 Why:    Outside of Linux, the only implementations of anything even
  39         vaguely resembling RCU that I am aware of are in DYNIX/ptx,
  40         VM/XA, Tornado, and K42.  I do not expect anyone to port binary
  41         drivers or kernel modules from any of these, since the first two
  42         are owned by IBM and the last two are open-source research OSes.
  43         So these will move to GPL after a grace period to allow
  44         people, who might be using implementations that I am not aware
  45         of, to adjust to this upcoming change.
  46 Who:    Paul E. McKenney <paulmck@us.ibm.com>
  47
  48 ---------------------------
  49
  50 What:   raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  51 When:   November 2005
  52 Why:    Deprecated in favour of the new ioctl-based rawiso interface, which is
  53         more efficient.  You should really be using libraw1394 for raw1394
  54         access anyway.
  55 Who:    Jody McIntyre <scjody@steamballoon.com>
  56
  57 ---------------------------
  58
  59 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  60 When:   July 2006
  61 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  62         series. The old API have lots of drawbacks and don't provide enough
  63         means to work with all video and audio standards. The newer API is
  64         already available on the main drivers and should be used instead.
  65         Newer drivers should use v4l_compat_translate_ioctl function to handle
  66         old calls, replacing to newer ones.
  67         Decoder iocts are using internally to allow video drivers to
  68         communicate with video decoders. This should also be improved to allow
  69         V4L2 calls being translated into compatible internal ioctls.
  70 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  71
  72 ---------------------------
  73
  74 What:   remove EXPORT_SYMBOL(panic_timeout)
  75 When:   April 2006
  76 Files:  kernel/panic.c
  77 Why:    No modular usage in the kernel.
  78 Who:    Adrian Bunk <bunk@stusta.de>
  79
  80 ---------------------------
  81
  82 What:   remove EXPORT_SYMBOL(insert_resource)
  83 When:   April 2006
  84 Files:  kernel/resource.c
  85 Why:    No modular usage in the kernel.
  86 Who:    Adrian Bunk <bunk@stusta.de>
  87
  88 ---------------------------
  89
  90 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  91 When:   November 2005
  92 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  93 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  94         normal hotpluggable bus, and with it using the default kernel
  95         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  96         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  97         unnecessary, and makes further cleanups and integration of the
  98         PCMCIA subsystem into the Linux kernel device driver model more
  99         difficult. The features provided by cardmgr and cardctl are either
 100         handled by the kernel itself now or are available in the new
 101         pcmciautils package available at
 102         http://kernel.org/pub/linux/utils/kernel/pcmcia/
 103 Who:    Dominik Brodowski <linux@brodo.de>
 104
 105 ---------------------------
 106
 107 What:   ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
 108 When:   December 2005
 109 Why:    This interface has been obsoleted by the new layer3-independent
 110         "nfnetlink_queue".  The Kernel interface is compatible, so the old
 111         ip[6]tables "QUEUE" targets still work and will transparently handle
 112         all packets into nfnetlink queue number 0.  Userspace users will have
 113         to link against API-compatible library on top of libnfnetlink_queue
 114         instead of the current 'libipq'.
 115 Who:    Harald Welte <laforge@netfilter.org>
 116
 117 ---------------------------
 118
 119 What:   remove EXPORT_SYMBOL(kernel_thread)
 120 When:   August 2006
 121 Files:  arch/*/kernel/*_ksyms.c
 122 Why:    kernel_thread is a low-level implementation detail.  Drivers should
 123         use the <linux/kthread.h> API instead which shields them from
 124         implementation details and provides a higherlevel interface that
 125         prevents bugs and code duplication
 126 Who:    Christoph Hellwig <hch@lst.de>
 127
 128 ---------------------------
 129
 130 What:   EXPORT_SYMBOL(lookup_hash)
 131 When:   January 2006
 132 Why:    Too low-level interface.  Use lookup_one_len or lookup_create instead.
 133 Who:    Christoph Hellwig <hch@lst.de>
 134
 135 ---------------------------
 136
 137 What:   CONFIG_FORCED_INLINING
 138 When:   June 2006
 139 Why:    Config option is there to see if gcc is good enough. (in january
 140         2006). If it is, the behavior should just be the default. If it's not,
 141         the option should just go away entirely.
 142 Who:    Arjan van de Ven
 143
 144 ---------------------------
 145
 146 What:   START_ARRAY ioctl for md
 147 When:   July 2006
 148 Files:  drivers/md/md.c
 149 Why:    Not reliable by design - can fail when most needed.
 150         Alternatives exist
 151 Who:    NeilBrown <neilb@suse.de>
 152
 153 ---------------------------
 154
 155 What:   au1x00_uart driver
 156 When:   January 2006
 157 Why:    The 8250 serial driver now has the ability to deal with the differences
 158         between the standard 8250 family of UARTs and their slightly strange
 159         brother on Alchemy SOCs.  The loss of features is not considered an
 160         issue.
 161 Who:    Ralf Baechle <ralf@linux-mips.org>
 162
 163 ---------------------------
 164
 165 What:   eepro100 network driver
 166 When:   January 2007
 167 Why:    replaced by the e100 driver
 168 Who:    Adrian Bunk <bunk@stusta.de>
 169
 170 ---------------------------
 171
 172 What:   pci_module_init(driver)
 173 When:   January 2007
 174 Why:    Is replaced by pci_register_driver(pci_driver).
 175 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 176
 177 ---------------------------
 178
 179 What:   Usage of invalid timevals in setitimer
 180 When:   March 2007
 181 Why:    POSIX requires to validate timevals in the setitimer call. This
 182         was never done by Linux. The invalid (e.g. negative timevals) were
 183         silently converted to more or less random timeouts and intervals.
 184         Until the removal a per boot limited number of warnings is printed
 185         and the timevals are sanitized.
 186
 187 Who:    Thomas Gleixner <tglx@linutronix.de>
 188
 189 ---------------------------
 190
 191 What:   I2C interface of the it87 driver
 192 When:   January 2007
 193 Why:    The ISA interface is faster and should be always available. The I2C
 194         probing is also known to cause trouble in at least one case (see
 195         bug #5889.)
 196 Who:    Jean Delvare <khali@linux-fr.org>
 197
 198 ---------------------------
 199
 200 What:   remove EXPORT_SYMBOL(tasklist_lock)
 201 When:   August 2006
 202 Files:  kernel/fork.c
 203 Why:    tasklist_lock protects the kernel internal task list.  Modules have
 204         no business looking at it, and all instances in drivers have been due
 205         to use of too-lowlevel APIs.  Having this symbol exported prevents
 206         moving to more scalable locking schemes for the task list.
 207 Who:    Christoph Hellwig <hch@lst.de>
 208
 209 ---------------------------
 210
 211 What:   mount/umount uevents
 212 When:   February 2007
 213 Why:    These events are not correct, and do not properly let userspace know
 214         when a file system has been mounted or unmounted.  Userspace should
 215         poll the /proc/mounts file instead to detect this properly.
 216 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 217
 218 ---------------------------
 219
 220 What:   Support for NEC DDB5074 and DDB5476 evaluation boards.
 221 When:   June 2006
 222 Why:    Board specific code doesn't build anymore since ~2.6.0 and no
 223         users have complained indicating there is no more need for these
 224         boards.  This should really be considered a last call.
 225 Who:    Ralf Baechle <ralf@linux-mips.org>
 226
 227 ---------------------------
 228
 229 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 230 When:   Febuary 2008
 231 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 232 Why:    The USB subsystem has changed a lot over time, and it has been
 233         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 234         that operate as fast as the USB bus allows.  Because of this, the USB
 235         subsystem will not be allowing closed source kernel drivers to
 236         register with it, after this grace period is over.  If anyone needs
 237         any help in converting their closed source drivers over to use the
 238         userspace filesystems, please contact the
 239         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 240         there will be glad to help you out.
 241 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 242
 243 ---------------------------
 244
 245 What:   find_trylock_page
 246 When:   January 2007
 247 Why:    The interface no longer has any callers left in the kernel. It
 248         is an odd interface (compared with other find_*_page functions), in
 249         that it does not take a refcount to the page, only the page lock.
 250         It should be replaced with find_get_page or find_lock_page if possible.
 251         This feature removal can be reevaluated if users of the interface
 252         cannot cleanly use something else.
 253 Who:    Nick Piggin <npiggin@suse.de>
 254
 255 ---------------------------