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 that were depending on OBSOLETE_OSS_DRIVER
  29         (config options already removed)
  30 When:   before 2.6.19
  31 Why:    OSS drivers with ALSA replacements
  32 Who:    Adrian Bunk <bunk@stusta.de>
  33
  34 ---------------------------
  35
  36 What:   RCU API moves to EXPORT_SYMBOL_GPL
  37 When:   April 2006
  38 Files:  include/linux/rcupdate.h, kernel/rcupdate.c
  39 Why:    Outside of Linux, the only implementations of anything even
  40         vaguely resembling RCU that I am aware of are in DYNIX/ptx,
  41         VM/XA, Tornado, and K42.  I do not expect anyone to port binary
  42         drivers or kernel modules from any of these, since the first two
  43         are owned by IBM and the last two are open-source research OSes.
  44         So these will move to GPL after a grace period to allow
  45         people, who might be using implementations that I am not aware
  46         of, to adjust to this upcoming change.
  47 Who:    Paul E. McKenney <paulmck@us.ibm.com>
  48
  49 ---------------------------
  50
  51 What:   raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  52 When:   November 2005
  53 Why:    Deprecated in favour of the new ioctl-based rawiso interface, which is
  54         more efficient.  You should really be using libraw1394 for raw1394
  55         access anyway.
  56 Who:    Jody McIntyre <scjody@steamballoon.com>
  57
  58 ---------------------------
  59
  60 What:   sbp2: module parameter "force_inquiry_hack"
  61 When:   July 2006
  62 Why:    Superceded by parameter "workarounds". Both parameters are meant to be
  63         used ad-hoc and for single devices only, i.e. not in modprobe.conf,
  64         therefore the impact of this feature replacement should be low.
  65 Who:    Stefan Richter <stefanr@s5r6.in-berlin.de>
  66
  67 ---------------------------
  68
  69 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  70 When:   July 2006
  71 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  72         series. The old API have lots of drawbacks and don't provide enough
  73         means to work with all video and audio standards. The newer API is
  74         already available on the main drivers and should be used instead.
  75         Newer drivers should use v4l_compat_translate_ioctl function to handle
  76         old calls, replacing to newer ones.
  77         Decoder iocts are using internally to allow video drivers to
  78         communicate with video decoders. This should also be improved to allow
  79         V4L2 calls being translated into compatible internal ioctls.
  80 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  81
  82 ---------------------------
  83
  84 What:   remove EXPORT_SYMBOL(insert_resource)
  85 When:   April 2006
  86 Files:  kernel/resource.c
  87 Why:    No modular usage in the kernel.
  88 Who:    Adrian Bunk <bunk@stusta.de>
  89
  90 ---------------------------
  91
  92 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  93 When:   November 2005
  94 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  95 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  96         normal hotpluggable bus, and with it using the default kernel
  97         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  98         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  99         unnecessary, and makes further cleanups and integration of the
 100         PCMCIA subsystem into the Linux kernel device driver model more
 101         difficult. The features provided by cardmgr and cardctl are either
 102         handled by the kernel itself now or are available in the new
 103         pcmciautils package available at
 104         http://kernel.org/pub/linux/utils/kernel/pcmcia/
 105 Who:    Dominik Brodowski <linux@brodo.de>
 106
 107 ---------------------------
 108
 109 What:   ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
 110 When:   December 2005
 111 Why:    This interface has been obsoleted by the new layer3-independent
 112         "nfnetlink_queue".  The Kernel interface is compatible, so the old
 113         ip[6]tables "QUEUE" targets still work and will transparently handle
 114         all packets into nfnetlink queue number 0.  Userspace users will have
 115         to link against API-compatible library on top of libnfnetlink_queue
 116         instead of the current 'libipq'.
 117 Who:    Harald Welte <laforge@netfilter.org>
 118
 119 ---------------------------
 120
 121 What:   remove EXPORT_SYMBOL(kernel_thread)
 122 When:   August 2006
 123 Files:  arch/*/kernel/*_ksyms.c
 124 Why:    kernel_thread is a low-level implementation detail.  Drivers should
 125         use the <linux/kthread.h> API instead which shields them from
 126         implementation details and provides a higherlevel interface that
 127         prevents bugs and code duplication
 128 Who:    Christoph Hellwig <hch@lst.de>
 129
 130 ---------------------------
 131
 132 What:   CONFIG_FORCED_INLINING
 133 When:   June 2006
 134 Why:    Config option is there to see if gcc is good enough. (in january
 135         2006). If it is, the behavior should just be the default. If it's not,
 136         the option should just go away entirely.
 137 Who:    Arjan van de Ven
 138
 139 ---------------------------
 140
 141 What:   START_ARRAY ioctl for md
 142 When:   July 2006
 143 Files:  drivers/md/md.c
 144 Why:    Not reliable by design - can fail when most needed.
 145         Alternatives exist
 146 Who:    NeilBrown <neilb@suse.de>
 147
 148 ---------------------------
 149
 150 What:   au1x00_uart driver
 151 When:   January 2006
 152 Why:    The 8250 serial driver now has the ability to deal with the differences
 153         between the standard 8250 family of UARTs and their slightly strange
 154         brother on Alchemy SOCs.  The loss of features is not considered an
 155         issue.
 156 Who:    Ralf Baechle <ralf@linux-mips.org>
 157
 158 ---------------------------
 159
 160 What:   eepro100 network driver
 161 When:   January 2007
 162 Why:    replaced by the e100 driver
 163 Who:    Adrian Bunk <bunk@stusta.de>
 164
 165 ---------------------------
 166
 167 What:   pci_module_init(driver)
 168 When:   January 2007
 169 Why:    Is replaced by pci_register_driver(pci_driver).
 170 Who:    Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
 171
 172 ---------------------------
 173
 174 What:   Usage of invalid timevals in setitimer
 175 When:   March 2007
 176 Why:    POSIX requires to validate timevals in the setitimer call. This
 177         was never done by Linux. The invalid (e.g. negative timevals) were
 178         silently converted to more or less random timeouts and intervals.
 179         Until the removal a per boot limited number of warnings is printed
 180         and the timevals are sanitized.
 181
 182 Who:    Thomas Gleixner <tglx@linutronix.de>
 183
 184 ---------------------------
 185
 186 What:   I2C interface of the it87 driver
 187 When:   January 2007
 188 Why:    The ISA interface is faster and should be always available. The I2C
 189         probing is also known to cause trouble in at least one case (see
 190         bug #5889.)
 191 Who:    Jean Delvare <khali@linux-fr.org>
 192
 193 ---------------------------
 194
 195 What:   remove EXPORT_SYMBOL(tasklist_lock)
 196 When:   August 2006
 197 Files:  kernel/fork.c
 198 Why:    tasklist_lock protects the kernel internal task list.  Modules have
 199         no business looking at it, and all instances in drivers have been due
 200         to use of too-lowlevel APIs.  Having this symbol exported prevents
 201         moving to more scalable locking schemes for the task list.
 202 Who:    Christoph Hellwig <hch@lst.de>
 203
 204 ---------------------------
 205
 206 What:   mount/umount uevents
 207 When:   February 2007
 208 Why:    These events are not correct, and do not properly let userspace know
 209         when a file system has been mounted or unmounted.  Userspace should
 210         poll the /proc/mounts file instead to detect this properly.
 211 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 212
 213 ---------------------------
 214
 215 What:   Support for NEC DDB5074 and DDB5476 evaluation boards.
 216 When:   June 2006
 217 Why:    Board specific code doesn't build anymore since ~2.6.0 and no
 218         users have complained indicating there is no more need for these
 219         boards.  This should really be considered a last call.
 220 Who:    Ralf Baechle <ralf@linux-mips.org>
 221
 222 ---------------------------
 223
 224 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 225 When:   Febuary 2008
 226 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 227 Why:    The USB subsystem has changed a lot over time, and it has been
 228         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 229         that operate as fast as the USB bus allows.  Because of this, the USB
 230         subsystem will not be allowing closed source kernel drivers to
 231         register with it, after this grace period is over.  If anyone needs
 232         any help in converting their closed source drivers over to use the
 233         userspace filesystems, please contact the
 234         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 235         there will be glad to help you out.
 236 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 237
 238 ---------------------------
 239
 240 What:   find_trylock_page
 241 When:   January 2007
 242 Why:    The interface no longer has any callers left in the kernel. It
 243         is an odd interface (compared with other find_*_page functions), in
 244         that it does not take a refcount to the page, only the page lock.
 245         It should be replaced with find_get_page or find_lock_page if possible.
 246         This feature removal can be reevaluated if users of the interface
 247         cannot cleanly use something else.
 248 Who:    Nick Piggin <npiggin@suse.de>
 249
 250 ---------------------------