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:   MXSER
  10 When:   December 2007
  11 Why:    Old mxser driver is obsoleted by the mxser_new. Give it some time yet
  12         and remove it.
  13 Who:    Jiri Slaby <jirislaby@gmail.com>
  14
  15 ---------------------------
  16
  17 What:   V4L2 VIDIOC_G_MPEGCOMP and VIDIOC_S_MPEGCOMP
  18 When:   October 2007
  19 Why:    Broken attempt to set MPEG compression parameters. These ioctls are
  20         not able to implement the wide variety of parameters that can be set
  21         by hardware MPEG encoders. A new MPEG control mechanism was created
  22         in kernel 2.6.18 that replaces these ioctls. See the V4L2 specification
  23         (section 1.9: Extended controls) for more information on this topic.
  24 Who:    Hans Verkuil <hverkuil@xs4all.nl> and
  25         Mauro Carvalho Chehab <mchehab@infradead.org>
  26
  27 ---------------------------
  28
  29 What:   /sys/devices/.../power/state
  30         dev->power.power_state
  31         dpm_runtime_{suspend,resume)()
  32 When:   July 2007
  33 Why:    Broken design for runtime control over driver power states, confusing
  34         driver-internal runtime power management with:  mechanisms to support
  35         system-wide sleep state transitions; event codes that distinguish
  36         different phases of swsusp "sleep" transitions; and userspace policy
  37         inputs.  This framework was never widely used, and most attempts to
  38         use it were broken.  Drivers should instead be exposing domain-specific
  39         interfaces either to kernel or to userspace.
  40 Who:    Pavel Machek <pavel@suse.cz>
  41
  42 ---------------------------
  43
  44 What:   old NCR53C9x driver
  45 When:   October 2007
  46 Why:    Replaced by the much better esp_scsi driver.  Actual low-level
  47         driver can be ported over almost trivially.
  48 Who:    David Miller <davem@davemloft.net>
  49         Christoph Hellwig <hch@lst.de>
  50
  51 ---------------------------
  52
  53 What:   Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  54 When:   December 2006
  55 Files:  include/linux/video_decoder.h
  56 Why:    V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  57         series. The old API have lots of drawbacks and don't provide enough
  58         means to work with all video and audio standards. The newer API is
  59         already available on the main drivers and should be used instead.
  60         Newer drivers should use v4l_compat_translate_ioctl function to handle
  61         old calls, replacing to newer ones.
  62         Decoder iocts are using internally to allow video drivers to
  63         communicate with video decoders. This should also be improved to allow
  64         V4L2 calls being translated into compatible internal ioctls.
  65 Who:    Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  66
  67 ---------------------------
  68
  69 What:   PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  70 When:   November 2005
  71 Files:  drivers/pcmcia/: pcmcia_ioctl.c
  72 Why:    With the 16-bit PCMCIA subsystem now behaving (almost) like a
  73         normal hotpluggable bus, and with it using the default kernel
  74         infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  75         control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  76         unnecessary, and makes further cleanups and integration of the
  77         PCMCIA subsystem into the Linux kernel device driver model more
  78         difficult. The features provided by cardmgr and cardctl are either
  79         handled by the kernel itself now or are available in the new
  80         pcmciautils package available at
  81         http://kernel.org/pub/linux/utils/kernel/pcmcia/
  82 Who:    Dominik Brodowski <linux@brodo.de>
  83
  84 ---------------------------
  85
  86 What:   remove EXPORT_SYMBOL(kernel_thread)
  87 When:   August 2006
  88 Files:  arch/*/kernel/*_ksyms.c
  89 Funcs:  kernel_thread
  90 Why:    kernel_thread is a low-level implementation detail.  Drivers should
  91         use the <linux/kthread.h> API instead which shields them from
  92         implementation details and provides a higherlevel interface that
  93         prevents bugs and code duplication
  94 Who:    Christoph Hellwig <hch@lst.de>
  95
  96 ---------------------------
  97
  98 What:   CONFIG_FORCED_INLINING
  99 When:   June 2006
 100 Why:    Config option is there to see if gcc is good enough. (in january
 101         2006). If it is, the behavior should just be the default. If it's not,
 102         the option should just go away entirely.
 103 Who:    Arjan van de Ven
 104
 105 ---------------------------
 106
 107 What:   eepro100 network driver
 108 When:   January 2007
 109 Why:    replaced by the e100 driver
 110 Who:    Adrian Bunk <bunk@stusta.de>
 111
 112 ---------------------------
 113
 114 What:   Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
 115         (temporary transition config option provided until then)
 116         The transition config option will also be removed at the same time.
 117 When:   before 2.6.19
 118 Why:    Unused symbols are both increasing the size of the kernel binary
 119         and are often a sign of "wrong API"
 120 Who:    Arjan van de Ven <arjan@linux.intel.com>
 121
 122 ---------------------------
 123
 124 What:   USB driver API moves to EXPORT_SYMBOL_GPL
 125 When:   February 2008
 126 Files:  include/linux/usb.h, drivers/usb/core/driver.c
 127 Why:    The USB subsystem has changed a lot over time, and it has been
 128         possible to create userspace USB drivers using usbfs/libusb/gadgetfs
 129         that operate as fast as the USB bus allows.  Because of this, the USB
 130         subsystem will not be allowing closed source kernel drivers to
 131         register with it, after this grace period is over.  If anyone needs
 132         any help in converting their closed source drivers over to use the
 133         userspace filesystems, please contact the
 134         linux-usb-devel@lists.sourceforge.net mailing list, and the developers
 135         there will be glad to help you out.
 136 Who:    Greg Kroah-Hartman <gregkh@suse.de>
 137
 138 ---------------------------
 139
 140 What:   Interrupt only SA_* flags
 141 When:   September 2007
 142 Why:    The interrupt related SA_* flags are replaced by IRQF_* to move them
 143         out of the signal namespace.
 144
 145 Who:    Thomas Gleixner <tglx@linutronix.de>
 146
 147 ---------------------------
 148
 149 What:   PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
 150 When:   October 2008
 151 Why:    The stacking of class devices makes these values misleading and
 152         inconsistent.
 153         Class devices should not carry any of these properties, and bus
 154         devices have SUBSYTEM and DRIVER as a replacement.
 155 Who:    Kay Sievers <kay.sievers@suse.de>
 156
 157 ---------------------------
 158
 159 What:   i2c-isa
 160 When:   December 2006
 161 Why:    i2c-isa is a non-sense and doesn't fit in the device driver
 162         model. Drivers relying on it are better implemented as platform
 163         drivers.
 164 Who:    Jean Delvare <khali@linux-fr.org>
 165
 166 ---------------------------
 167
 168 What:   i2c_adapter.list
 169 When:   July 2007
 170 Why:    Superfluous, this list duplicates the one maintained by the driver
 171         core.
 172 Who:    Jean Delvare <khali@linux-fr.org>,
 173         David Brownell <dbrownell@users.sourceforge.net>
 174
 175 ---------------------------
 176
 177 What:  drivers depending on OBSOLETE_OSS
 178 When:  options in 2.6.22, code in 2.6.24
 179 Why:   OSS drivers with ALSA replacements
 180 Who:   Adrian Bunk <bunk@stusta.de>
 181
 182 ---------------------------
 183
 184 What:   /sys/firmware/acpi/namespace
 185 When:   2.6.21
 186 Why:    The ACPI namespace is effectively the symbol list for
 187         the BIOS.  The device names are completely arbitrary
 188         and have no place being exposed to user-space.
 189
 190         For those interested in the BIOS ACPI namespace,
 191         the BIOS can be extracted and disassembled with acpidump
 192         and iasl as documented in the pmtools package here:
 193         http://ftp.kernel.org/pub/linux/kernel/people/lenb/acpi/utils
 194 Who:    Len Brown <len.brown@intel.com>
 195
 196 ---------------------------
 197
 198 What:   ACPI procfs interface
 199 When:   July 2007
 200 Why:    After ACPI sysfs conversion, ACPI attributes will be duplicated
 201         in sysfs and the ACPI procfs interface should be removed.
 202 Who:    Zhang Rui <rui.zhang@intel.com>
 203
 204 ---------------------------
 205
 206 What:   /proc/acpi/button
 207 When:   August 2007
 208 Why:    /proc/acpi/button has been replaced by events to the input layer
 209         since 2.6.20.
 210 Who:    Len Brown <len.brown@intel.com>
 211
 212 ---------------------------
 213
 214 What:   Compaq touchscreen device emulation
 215 When:   Oct 2007
 216 Files:  drivers/input/tsdev.c
 217 Why:    The code says it was obsolete when it was written in 2001.
 218         tslib is a userspace library which does anything tsdev can do and
 219         much more besides in userspace where this code belongs. There is no
 220         longer any need for tsdev and applications should have converted to
 221         use tslib by now.
 222         The name "tsdev" is also extremely confusing and lots of people have
 223         it loaded when they don't need/use it.
 224 Who:    Richard Purdie <rpurdie@rpsys.net>
 225
 226 ---------------------------
 227
 228 What:   read_dev_chars(), read_conf_data{,_lpm}() (s390 common I/O layer)
 229 When:   December 2007
 230 Why:    These functions are a leftover from 2.4 times. They have several
 231         problems:
 232         - Duplication of checks that are done in the device driver's
 233           interrupt handler
 234         - common I/O layer can't do device specific error recovery
 235         - device driver can't be notified for conditions happening during
 236           execution of the function
 237         Device drivers should issue the read device characteristics and read
 238         configuration data ccws and do the appropriate error handling
 239         themselves.
 240 Who:    Cornelia Huck <cornelia.huck@de.ibm.com>
 241
 242 ---------------------------
 243
 244 What:   i2c-ixp2000, i2c-ixp4xx and scx200_i2c drivers
 245 When:   September 2007
 246 Why:    Obsolete. The new i2c-gpio driver replaces all hardware-specific
 247         I2C-over-GPIO drivers.
 248 Who:    Jean Delvare <khali@linux-fr.org>
 249
 250 ---------------------------
 251
 252 What:   'time' kernel boot parameter
 253 When:   January 2008
 254 Why:    replaced by 'printk.time=<value>' so that printk timestamps can be
 255         enabled or disabled as needed
 256 Who:    Randy Dunlap <randy.dunlap@oracle.com>
 257
 258 ---------------------------
 259
 260 What:  drivers depending on OSS_OBSOLETE
 261 When:  options in 2.6.23, code in 2.6.25
 262 Why:   obsolete OSS drivers
 263 Who:   Adrian Bunk <bunk@stusta.de>
 264
 265 ---------------------------
 266
 267 What: libata spindown skipping and warning
 268 When: Dec 2008
 269 Why:  Some halt(8) implementations synchronize caches for and spin
 270       down libata disks because libata didn't use to spin down disk on
 271       system halt (only synchronized caches).
 272       Spin down on system halt is now implemented.  sysfs node
 273       /sys/class/scsi_disk/h:c:i:l/manage_start_stop is present if
 274       spin down support is available.
 275       Because issuing spin down command to an already spun down disk
 276       makes some disks spin up just to spin down again, libata tracks
 277       device spindown status to skip the extra spindown command and
 278       warn about it.
 279       This is to give userspace tools the time to get updated and will
 280       be removed after userspace is reasonably updated.
 281 Who:  Tejun Heo <htejun@gmail.com>
 282
 283 ---------------------------
 284
 285 What:   Legacy RTC drivers (under drivers/i2c/chips)
 286 When:   November 2007
 287 Why:    Obsolete. We have a RTC subsystem with better drivers.
 288 Who:    Jean Delvare <khali@linux-fr.org>
 289
 290 ---------------------------
 291
 292 What:   iptables SAME target
 293 When:   1.1. 2008
 294 Files:  net/ipv4/netfilter/ipt_SAME.c, include/linux/netfilter_ipv4/ipt_SAME.h
 295 Why:    Obsolete for multiple years now, NAT core provides the same behaviour.
 296         Unfixable broken wrt. 32/64 bit cleanness.
 297 Who:    Patrick McHardy <kaber@trash.net>
 298
 299 ---------------------------
 300
 301 What: The arch/ppc and include/asm-ppc directories
 302 When: Jun 2008
 303 Why:  The arch/powerpc tree is the merged architecture for ppc32 and ppc64
 304       platforms.  Currently there are efforts underway to port the remaining
 305       arch/ppc platforms to the merged tree.  New submissions to the arch/ppc
 306       tree have been frozen with the 2.6.22 kernel release and that tree will
 307       remain in bug-fix only mode until its scheduled removal.  Platforms
 308       that are not ported by June 2008 will be removed due to the lack of an
 309       interested maintainer.
 310 Who:  linuxppc-dev@ozlabs.org
 311
 312 ---------------------------