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(insert_resource)
  75 When:   April 2006
  76 Files:  kernel/resource.c
  77 Why:    No modular usage in the kernel.
  78 Who:    Adrian Bunk <bunk@stusta.de>
  79
  80 ---------------------------
  81
  82 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  83 When:   November 2005
  84 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  85 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  86         normal hotpluggable bus, and with it using the default kernel
  87         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  88         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  89         unnecessary, and makes further cleanups and integration of the
  90         PCMCIA subsystem into the Linux kernel device driver model more
  91         difficult. The features provided by cardmgr and cardctl are either
  92         handled by the kernel itself now or are available in the new
  93         pcmciautils package available at
  94         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  95 Who:    Dominik Brodowski <linux@brodo.de>
  96
  97 ---------------------------
  98
  99 What:   ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
 100 When:   December 2005
 101 Why:    This interface has been obsoleted by the new layer3-independent
 102         "nfnetlink_queue".  The Kernel interface is compatible, so the old
 103         ip[6]tables "QUEUE" targets still work and will transparently handle
 104         all packets into nfnetlink queue number 0.  Userspace users will have
 105         to link against API-compatible library on top of libnfnetlink_queue
 106         instead of the current 'libipq'.
 107 Who:    Harald Welte <laforge@netfilter.org>
 108
 109 ---------------------------
 110
 111 What:   remove EXPORT_SYMBOL(kernel_thread)
 112 When:   August 2006
 113 Files:  arch/*/kernel/*_ksyms.c
 114 Why:    kernel_thread is a low-level implementation detail.  Drivers should
 115         use the <linux/kthread.h> API instead which shields them from
 116         implementation details and provides a higherlevel interface that
 117         prevents bugs and code duplication
 118 Who:    Christoph Hellwig <hch@lst.de>
 119
 120 ---------------------------
 121
 122 What:   CONFIG_FORCED_INLINING
 123 When:   June 2006
 124 Why:    Config option is there to see if gcc is good enough. (in january
 125         2006). If it is, the behavior should just be the default. If it's not,
 126         the option should just go away entirely.
 127 Who:    Arjan van de Ven
 128
 129 ---------------------------
 130
 131 What:   START_ARRAY ioctl for md
 132 When:   July 2006
 133 Files:  drivers/md/md.c
 134 Why:    Not reliable by design - can fail when most needed.
 135         Alternatives exist
 136 Who:    NeilBrown <neilb@suse.de>
 137
 138 ---------------------------
 139
 140 What:   au1x00_uart driver
 141 When:   January 2006
 142 Why:    The 8250 serial driver now has the ability to deal with the differences
 143         between the standard 8250 family of UARTs and their slightly strange
 144         brother on Alchemy SOCs.  The loss of features is not considered an
 145         issue.
 146 Who:    Ralf Baechle <ralf@linux-mips.org>
 147
 148 ---------------------------
 149
 150 What:   eepro100 network driver
 151 When:   January 2007
 152 Why:    replaced by the e100 driver
 153 Who:    Adrian Bunk <bunk@stusta.de>
 154
 155 ---------------------------
 156
 157 What:   pci_module_init(driver)
 158 When:   January 2007
 159 Why:    Is replaced by pci_register_driver(pci_driver).
 160 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 161
 162 ---------------------------
 163
 164 What:   Usage of invalid timevals in setitimer
 165 When:   March 2007
 166 Why:    POSIX requires to validate timevals in the setitimer call. This
 167         was never done by Linux. The invalid (e.g. negative timevals) were
 168         silently converted to more or less random timeouts and intervals.
 169         Until the removal a per boot limited number of warnings is printed
 170         and the timevals are sanitized.
 171
 172 Who:    Thomas Gleixner <tglx@linutronix.de>
 173
 174 ---------------------------
 175
 176 What:   I2C interface of the it87 driver
 177 When:   January 2007
 178 Why:    The ISA interface is faster and should be always available. The I2C
 179         probing is also known to cause trouble in at least one case (see
 180         bug #5889.)
 181 Who:    Jean Delvare <khali@linux-fr.org>
 182
 183 ---------------------------
 184
 185 What:   remove EXPORT_SYMBOL(tasklist_lock)
 186 When:   August 2006
 187 Files:  kernel/fork.c
 188 Why:    tasklist_lock protects the kernel internal task list.  Modules have
 189         no business looking at it, and all instances in drivers have been due
 190         to use of too-lowlevel APIs.  Having this symbol exported prevents
 191         moving to more scalable locking schemes for the task list.
 192 Who:    Christoph Hellwig <hch@lst.de>
 193
 194 ---------------------------
 195
 196 What:   mount/umount uevents
 197 When:   February 2007
 198 Why:    These events are not correct, and do not properly let userspace know
 199         when a file system has been mounted or unmounted.  Userspace should
 200         poll the /proc/mounts file instead to detect this properly.
 201 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 202
 203 ---------------------------
 204
 205 What:   Support for NEC DDB5074 and DDB5476 evaluation boards.
 206 When:   June 2006
 207 Why:    Board specific code doesn't build anymore since ~2.6.0 and no
 208         users have complained indicating there is no more need for these
 209         boards.  This should really be considered a last call.
 210 Who:    Ralf Baechle <ralf@linux-mips.org>
 211
 212 ---------------------------
 213
 214 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 215 When:   Febuary 2008
 216 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 217 Why:    The USB subsystem has changed a lot over time, and it has been
 218         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 219         that operate as fast as the USB bus allows.  Because of this, the USB
 220         subsystem will not be allowing closed source kernel drivers to
 221         register with it, after this grace period is over.  If anyone needs
 222         any help in converting their closed source drivers over to use the
 223         userspace filesystems, please contact the
 224         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 225         there will be glad to help you out.
 226 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 227
 228 ---------------------------
 229
 230 What:   find_trylock_page
 231 When:   January 2007
 232 Why:    The interface no longer has any callers left in the kernel. It
 233         is an odd interface (compared with other find_*_page functions), in
 234         that it does not take a refcount to the page, only the page lock.
 235         It should be replaced with find_get_page or find_lock_page if possible.
 236         This feature removal can be reevaluated if users of the interface
 237         cannot cleanly use something else.
 238 Who:    Nick Piggin <npiggin@suse.de>
 239
 240 ---------------------------