OpenCloudOS-Kernel/Documentation/feature-removal-schedule.txt

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The following is a list of files and features that are going to be
removed in the kernel source tree. Every entry should contain what
exactly is going away, why it is happening, and who is going to be doing
the work. When the feature is removed from the kernel, it should also
be removed from this file.
---------------------------
What: devfs
When: July 2005
Files: fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
function calls throughout the kernel tree
Why: It has been unmaintained for a number of years, has unfixable
races, contains a naming policy within the kernel that is
against the LSB, and can be replaced by using udev.
Who: Greg Kroah-Hartman <greg@kroah.com>
---------------------------
What: RAW driver (CONFIG_RAW_DRIVER)
When: December 2005
Why: declared obsolete since kernel 2.6.3
O_DIRECT can be used instead
Who: Adrian Bunk <bunk@stusta.de>
---------------------------
What: drivers that were depending on OBSOLETE_OSS_DRIVER
(config options already removed)
When: before 2.6.19
Why: OSS drivers with ALSA replacements
Who: Adrian Bunk <bunk@stusta.de>
---------------------------
What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
When: November 2006
Why: Deprecated in favour of the new ioctl-based rawiso interface, which is
more efficient. You should really be using libraw1394 for raw1394
access anyway.
Who: Jody McIntyre <scjody@modernduck.com>
---------------------------
What: sbp2: module parameter "force_inquiry_hack"
When: July 2006
Why: Superceded by parameter "workarounds". Both parameters are meant to be
used ad-hoc and for single devices only, i.e. not in modprobe.conf,
therefore the impact of this feature replacement should be low.
Who: Stefan Richter <stefanr@s5r6.in-berlin.de>
---------------------------
What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
When: July 2006
Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
series. The old API have lots of drawbacks and don't provide enough
means to work with all video and audio standards. The newer API is
already available on the main drivers and should be used instead.
Newer drivers should use v4l_compat_translate_ioctl function to handle
old calls, replacing to newer ones.
Decoder iocts are using internally to allow video drivers to
communicate with video decoders. This should also be improved to allow
V4L2 calls being translated into compatible internal ioctls.
Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
---------------------------
What: remove EXPORT_SYMBOL(insert_resource)
When: April 2006
Files: kernel/resource.c
Why: No modular usage in the kernel.
Who: Adrian Bunk <bunk@stusta.de>
---------------------------
What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
When: November 2005
Files: drivers/pcmcia/: pcmcia_ioctl.c
Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
normal hotpluggable bus, and with it using the default kernel
infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
control ioctl needed by cardmgr and cardctl from pcmcia-cs is
unnecessary, and makes further cleanups and integration of the
PCMCIA subsystem into the Linux kernel device driver model more
difficult. The features provided by cardmgr and cardctl are either
handled by the kernel itself now or are available in the new
pcmciautils package available at
http://kernel.org/pub/linux/utils/kernel/pcmcia/
Who: Dominik Brodowski <linux@brodo.de>
---------------------------
What: ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
When: December 2005
Why: This interface has been obsoleted by the new layer3-independent
"nfnetlink_queue". The Kernel interface is compatible, so the old
ip[6]tables "QUEUE" targets still work and will transparently handle
all packets into nfnetlink queue number 0. Userspace users will have
to link against API-compatible library on top of libnfnetlink_queue
instead of the current 'libipq'.
Who: Harald Welte <laforge@netfilter.org>
---------------------------
What: remove EXPORT_SYMBOL(kernel_thread)
When: August 2006
Files: arch/*/kernel/*_ksyms.c
Why: kernel_thread is a low-level implementation detail. Drivers should
use the <linux/kthread.h> API instead which shields them from
implementation details and provides a higherlevel interface that
prevents bugs and code duplication
Who: Christoph Hellwig <hch@lst.de>
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What: CONFIG_FORCED_INLINING
When: June 2006
Why: Config option is there to see if gcc is good enough. (in january
2006). If it is, the behavior should just be the default. If it's not,
the option should just go away entirely.
Who: Arjan van de Ven
---------------------------
What: START_ARRAY ioctl for md
When: July 2006
Files: drivers/md/md.c
Why: Not reliable by design - can fail when most needed.
Alternatives exist
Who: NeilBrown <neilb@suse.de>
---------------------------
What: au1x00_uart driver
When: January 2006
Why: The 8250 serial driver now has the ability to deal with the differences
between the standard 8250 family of UARTs and their slightly strange
brother on Alchemy SOCs. The loss of features is not considered an
issue.
Who: Ralf Baechle <ralf@linux-mips.org>
---------------------------
What: eepro100 network driver
When: January 2007
Why: replaced by the e100 driver
Who: Adrian Bunk <bunk@stusta.de>
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What: pci_module_init(driver)
When: January 2007
Why: Is replaced by pci_register_driver(pci_driver).
Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
---------------------------
What: Usage of invalid timevals in setitimer
When: March 2007
Why: POSIX requires to validate timevals in the setitimer call. This
was never done by Linux. The invalid (e.g. negative timevals) were
silently converted to more or less random timeouts and intervals.
Until the removal a per boot limited number of warnings is printed
and the timevals are sanitized.
Who: Thomas Gleixner <tglx@linutronix.de>
---------------------------
What: I2C interface of the it87 driver
When: January 2007
Why: The ISA interface is faster and should be always available. The I2C
probing is also known to cause trouble in at least one case (see
bug #5889.)
Who: Jean Delvare <khali@linux-fr.org>
---------------------------
What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
(temporary transition config option provided until then)
The transition config option will also be removed at the same time.
When: before 2.6.19
Why: Unused symbols are both increasing the size of the kernel binary
and are often a sign of "wrong API"
Who: Arjan van de Ven <arjan@linux.intel.com>
---------------------------
What: remove EXPORT_SYMBOL(tasklist_lock)
When: August 2006
Files: kernel/fork.c
Why: tasklist_lock protects the kernel internal task list. Modules have
no business looking at it, and all instances in drivers have been due
to use of too-lowlevel APIs. Having this symbol exported prevents
moving to more scalable locking schemes for the task list.
Who: Christoph Hellwig <hch@lst.de>
---------------------------
What: mount/umount uevents
When: February 2007
Why: These events are not correct, and do not properly let userspace know
when a file system has been mounted or unmounted. Userspace should
poll the /proc/mounts file instead to detect this properly.
Who: Greg Kroah-Hartman <gregkh@suse.de>
---------------------------
What: USB driver API moves to EXPORT_SYMBOL_GPL
When: Febuary 2008
Files: include/linux/usb.h, drivers/usb/core/driver.c
Why: The USB subsystem has changed a lot over time, and it has been
possible to create userspace USB drivers using usbfs/libusb/gadgetfs
that operate as fast as the USB bus allows. Because of this, the USB
subsystem will not be allowing closed source kernel drivers to
register with it, after this grace period is over. If anyone needs
any help in converting their closed source drivers over to use the
userspace filesystems, please contact the
linux-usb-devel@lists.sourceforge.net mailing list, and the developers
there will be glad to help you out.
Who: Greg Kroah-Hartman <gregkh@suse.de>
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What: find_trylock_page
When: January 2007
Why: The interface no longer has any callers left in the kernel. It
is an odd interface (compared with other find_*_page functions), in
that it does not take a refcount to the page, only the page lock.
It should be replaced with find_get_page or find_lock_page if possible.
This feature removal can be reevaluated if users of the interface
cannot cleanly use something else.
Who: Nick Piggin <npiggin@suse.de>
---------------------------