Commit graph

407 commits

Author SHA1 Message Date
Stuart Hayes
116ee77b28 dell-laptop: Use buffer with 32-bit physical address
Calls to communicate with system firmware via a SMI (using dcdbas)
need to use a buffer that has a physical address of 4GB or less.
Currently the dell-laptop driver does not guarantee this, and when the
buffer address is higher than 4GB, the address is truncated to 32 bits
and the SMI handler writes to the wrong memory address.

Signed-off-by: Stuart Hayes <stuart_hayes@dell.com>
Acked-by: Matthew Garrett <mjg@redhat.com>
2010-02-25 11:50:49 -05:00
Mario Limonciello
e5fefd0c8c dell-laptop: Blacklist machines not supporting dell-laptop
The Mini family doesn't support smbios 17,11 although it reports it does.

Signed-off-by: Mario Limonciello <superm1@ubuntu.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
2010-02-25 11:50:48 -05:00
Mario Limonciello
ec1722a214 dell-laptop: Block software state changes when rfkill hard blocked
The "hardware" switch is tied directly to a BIOS interface that will
connect and disconnect the hardware from the bus.

If you use the software interface to request the BIOS to make these
changes, the HW switch will be in an inconsistent state and LEDs may not
reflect the state of the HW.

Signed-off-by: Mario Limonciello <Mario_Limonciello@Dell.com>
2010-02-25 11:50:46 -05:00
Matthew Garrett
e551260b23 dell-laptop: Fix small memory leak
da_tokens was not being freed by dell-laptop on unload. Fix that.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
2010-02-25 11:50:44 -05:00
Matthew Garrett
facd61d7b7 dell-laptop: Fix platform device unregistration
dell-laptop currently fails to clean up its platform device correctly.
Make sure that it's unregistered.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
2010-02-25 11:50:43 -05:00
Matthew Garrett
814cb8adbe dell-laptop: Update rfkill state on kill switch
The rfkill interface on Dells only sends a notification that the switch
has been changed via the keyboard controller. Add a filter so we can
pick these notifications up and update the rfkill state appropriately.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
2010-02-25 11:50:42 -05:00
Mario Limonciello
493e91433e compal-laptop: Replace sysfs support with rfkill support
This drops the support for manually groking the files in sysfs
to turn on and off the WLAN and BT for Compal laptops in favor
of platform rfkill support.

It has been combined into a single patch to not introduce regressions
in the process of simply adding rfkill support

Signed-off-by: Mario Limonciello <Mario_Limonciello@Dell.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Cezary Jackiewicz <cezary.jackiewicz@gmail.com>
2010-02-25 11:50:40 -05:00
Mario Limonciello
34325b9d2a compal-laptop: Add support for known Compal made Dell laptops
The following Dell laptops are known to have been manufacturer by Compal
and are supported by the compal-laptop platform driver
 - Mini 9
 - Mini 10
 - Mini 12
 - Mini 10v
 - Inspiron 11z

Signed-off-by: Mario Limonciello <Mario_Limonciello@Dell.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: Cezary Jackiewicz <cezary.jackiewicz@gmail.com>
2010-02-25 11:50:39 -05:00
Carlos Corbacho
6f6ef82cc9 acer-wmi: Respect current backlight level when loading
Set the backlight to use the current brightness when loaded, rather than
always resetting the backlight to maximum brightness.

Fixes kernel bugzilla #14207

Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Reported-by: Denis Mukhin <denis_mukhin@yahoo.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-02-19 00:19:26 -05:00
Roel Kluin
f04d5e012d thinkpad-acpi: wrong thermal attribute_group removed in thermal_exit()
sysfs_remove_group() removed the wrong attribute_group for
thermal_read_mode TPEC_8, ACPI_TMP07 and ACPI_UPDT

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Henrique de Moraes Holschuh <ibm-acpi@hmh.eng.br>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-02-16 03:10:10 -05:00
Len Brown
be6066f34c Merge branch 'misc' into release 2010-01-20 01:23:27 -05:00
Dmitry Torokhov
c14973f930 sony-laptop - fix using of uninitialized variable
CC [M]  drivers/platform/x86/sony-laptop.o
drivers/platform/x86/sony-laptop.c: In function 'sony_nc_rfkill_setup':
drivers/platform/x86/sony-laptop.c:1162: warning: 'i' may be used uninitialized in this function

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-16 15:55:43 -05:00
Corentin Chary
4194e2f551 eeepc-laptop: disable wireless hotplug for 1201N
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-16 01:50:05 -05:00
Corentin Chary
322a1356be eeepc-laptop: add hotplug_disable parameter
Some new models need to disable wireless hotplug.
For the moment, we don't know excactly what models need that,
except 1005HA.
Users will be able to use that param as a workaround.

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-16 01:49:50 -05:00
Dmitry Torokhov
642e0447cb eeepc-laptop: switch to using sparse keymap library
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Tested-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-16 01:49:41 -05:00
Corentin Chary
10ae4b5663 eeepc-laptop: dmi blacklist to disable pci hotplug code
This is a short term workaround for Eeepc 1005HA.

refs: <http://bugzilla.kernel.org/show_bug.cgi?id=14570>

Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-16 01:49:28 -05:00
Alan Jenkins
da8ba01deb eeepc-laptop: disable cpu speed control on EeePC 701
The EeePC 4G ("701") implements CFVS, but it is not supported by the
pre-installed OS, and the original option to change it in the BIOS
setup screen was removed in later versions.  Judging by the lack of
"Super Hybrid Engine" on Asus product pages, this applies to all "701"
models (4G/4G Surf/2G Surf).

So Asus made a deliberate decision not to support it on this model.
We have several reports that using it can cause the system to hang [1].
That said, it does not happen all the time.  Some users do not
experience it at all (and apparently wish to continue "right-clocking").

Check for the EeePC 701 using DMI.  If met, then disable writes to the
"cpufv" sysfs attribute and log an explanatory message.

Add a "cpufv_disabled" attribute which allow users to override this
policy.  Writing to this attribute will log a second message.

The sysfs attribute is more useful than a module option, because it
makes it easier for userspace scripts to provide consistent behaviour
(according to user configuration), regardless of whether the kernel
includes this change.

[1] <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=559578>

Signed-off-by: Alan Jenkins <alan-jenkins@tuffmail.co.uk>
Signed-off-by: Corentin Chary <corentincj@iksaif.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-16 01:49:13 -05:00
Anisse Astier
c9c041fcb1 hp-wmi: remove double free caused by merge conflict
Commit 3e9b988e4e
"wmi: Free the allocated acpi objects through wmi_get_event_data"
had the same purpose as commit
44ef00e648
"hp-wmi: Fix two memleaks"

This should solve this regression:

http://bugzilla.kernel.org/show_bug.cgi?id=14890

Signed-off-by: Anisse Astier <anisse@astier.eu>
Reported-by: Sedat Dilek <sedat.dilek@googlemail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-01 14:04:25 -05:00
Len Brown
ea840aa2d0 Merge branch 'thinkpad' into release 2009-12-30 02:51:05 -05:00
Carlos Corbacho
d1f9e49707 ACPI: WMI: Survive BIOS with duplicate GUIDs
It would appear that in BIOS's with nVidia hooks, the GUID
05901221-D566-11D1-B2F0-00A0C9062910 is duplicated. For now, the simplest
solution is to just ignore any duplicate GUIDs. These particular hooks are not
currently supported/ used in the kernel, so whoever does that can figure out
what the 'right' solution should be (if there's a better one).

http://bugzilla.kernel.org/show_bug.cgi?id=14846

Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Reported-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Oldřich Jedlička <oldium.pro@seznam.cz>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30 02:49:04 -05:00
Dmitry Torokhov
7a9568f536 dell-wmi - fix condition to abort driver loading
From: Dmitry Torokhov <dmitry.torokhov@gmail.com>

The commit 1fdd407f4e incorrectly made driver
abort loading when known GUID is present when it should have done exactly
the opposite.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30 02:49:03 -05:00
Paul Rolland
c03b26a5a5 wmi: check find_guid() return value to prevent oops
Signed-off-by: Paul Rolland <rol@as2917.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30 02:48:55 -05:00
Len Brown
fda11e61ff dell-wmi, hp-wmi, msi-wmi: check wmi_get_event_data() return value
When acpi_evaluate_object() is passed ACPI_ALLOCATE_BUFFER,
the caller must kfree the returned buffer if AE_OK is returned.

The callers of wmi_get_event_data() pass ACPI_ALLOCATE_BUFFER,
and thus must check its return value before accessing
or kfree() on the buffer.

Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30 02:48:52 -05:00
Len Brown
f27725756b ACPI: hp-wmi, msi-wmi: clarify that wmi_install_notify_handler() returns an acpi_status
Emphasize that that wmi_install_notify_handler() returns an acpi_status
rather than -errno by by testing ACPI_SUCCESS(), ACPI_FAILURE().

No functional change in this patch, but this confusion caused a bug in dell-wmi.

Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30 02:48:52 -05:00
Len Brown
abb631bfe2 dell-wmi: sys_init_module: 'dell_wmi'->init suspiciously returned 21, it should
follow 0/-E convention

wmi_install_notify_handler() returns an acpi_error,
but dell_wmi_init() needs return a -errno style error.

Tested-by: Paul Rolland <rol@as2917.net>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30 02:48:38 -05:00
Henrique de Moraes Holschuh
6e5b08ee94 thinkpad-acpi: improve Kconfig help text
Document that rfkill and ALSA functionality exists, but requires the
subsystems to be available, and not modular if thinkpad-acpi is not
modular.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-26 22:38:08 -05:00
Henrique de Moraes Holschuh
ff850c339a thinkpad-acpi: make volume subdriver optional
Allow the user to choose through Kconfig if the Console Audio Control
interface (aka "volume subdriver") should be available or not.

This not only saves some memory, but also allows the thinkpad-acpi
driver to be built-in even if ALSA is modular when the console audio
control interface is not wanted.

This change fixes a build problem that is causing some annoyances, in
a way that doesn't disable the entire driver on kernels without ALSA
support.

Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Amerigo Wang <amwang@redhat.com>
Cc: Helight Xu <helight.xu@gmail.com>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-26 22:37:35 -05:00
Henrique de Moraes Holschuh
74c75c1848 thinkpad-acpi: don't fail to load the entire module due to ALSA problems
If we cannot create the ALSA mixer, it is a good reason to fail to
load the volume subdriver, and not to fail to load the entire module.

While at it, add more debugging messages, as the error paths are being
used a lot more than I'd expect, and it is failing to set up the ALSA
mixer on a number of ThinkPads.

Reported-by: Peter Jordan <usernetwork@gmx.info>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-26 22:37:20 -05:00
Henrique de Moraes Holschuh
ead510cebc thinkpad-acpi: don't take the first ALSA slot by default
We don't want to be the first soundcard.  We don't want to shift other
soundcards out of the way either, even if they load much later.

Ask ALSA to (by default) load us in one of the last three slots.  This
can be overriden at will using the "index" parameter.

Reported-by: Whoopie <whoopie79@gmx.net>
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-26 22:37:08 -05:00
Len Brown
fcb11235d3 Merge branch 'misc-2.6.33' into release 2009-12-24 01:19:00 -05:00
Len Brown
78a5331ddd Merge branch 'tc1100-wmi' into release 2009-12-24 01:17:46 -05:00
Len Brown
fe7fa9c51a Merge branch 'sony' into release 2009-12-24 01:17:41 -05:00
Len Brown
6d3bf6818a Merge branch 'classmate' into release 2009-12-24 01:17:31 -05:00
Thadeu Lima de Souza Cascardo
529aa8cb0a classmate-laptop: add support for Classmate PC ACPI devices
This add supports for devices like keyboard, backlight, tablet and
accelerometer.

This work is supported by International Syst S/A.

[randy.dunlap@oracle.com: cmpc_acpi: depends on ACPI]
[akpm@linux-foundation.org: readability tweaks]
[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 01:16:04 -05:00
Thomas Renninger
44ef00e648 hp-wmi: Fix two memleaks
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:54:49 -05:00
Thomas Renninger
4d5f177caf acer-wmi, msi-wmi: Remove needless DMI MODULE_ALIAS
Now that we have WMI autoloading
the DMI matching is not needed anymore.

Signed-off-by: Thomas Renninger <trenn@suse.de>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Acked-by: Anisse Astier <anisse@astier.eu>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:50:28 -05:00
Dmitry Torokhov
1fdd407f4e dell-wmi: do not keep driver loaded on unsupported boxes
There is no point in having the driver loaded in memory if we fail
to locate particular WMI GUID.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
Acked-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:44:46 -05:00
Anisse Astier
3e9b988e4e wmi: Free the allocated acpi objects through wmi_get_event_data
These function allocate an acpi object by calling wmi_get_event_data, which
then calls acpi_evaluate_object, and it is not freed afterwards.

And kernel doc is fixed for parameters of wmi_get_event_data.

Signed-off-by: Anisse Astier <anisse@astier.eu>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:42:00 -05:00
Peter Feuerer
dcbfb8156a drivers/platform/x86/acerhdf.c: check BIOS information whether it begins with string of table
BIOS information is now checked whether it begins with the strings stored
in the BIOS table.  Previous method did a strcmp, what lead to problems if
BIOS information has appended whitespaces.

Signed-off-by: Peter Feuerer <peter@piie.net>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Andreas Mohr <andi@lisas.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:17:09 -05:00
Peter Feuerer
94219d798e acerhdf: add new BIOS versions
Add new BIOS versions for following netbooks: Aspire 1810xx, Packard Bell
DOTMU.

Signed-off-by: Peter Feuerer <peter@piie.net>
Cc: Borislav Petkov <petkovbb@gmail.com>
Cc: Andreas Mohr <andi@lisas.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:16:46 -05:00
Stefan Bader
bdc731bc5f acerhdf: limit modalias matching to supported
BugLink: https://bugs.launchpad.net/ubuntu/+bug/435958

The module alias currently matches any Acer computer but when loaded the
BIOS checks will only succeed on Aspire One models.  This causes a invalid
BIOS warning for all other models (seen on Aspire 4810T).  This is not
fatal but worries users that see this message.  Limiting the moule alias
to models starting with AOA or DOA for Packard Bell.

Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Borislav Petkov <petkovbb@gmail.com>
Acked-by: Peter Feuerer <peter@piie.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:16:28 -05:00
Alexey Dobriyan
936c8bcd7f toshiba_acpi: convert to seq_file
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:15:10 -05:00
Alexey Dobriyan
ff93be5dea asus_acpi: convert to seq_file
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Corentin Chary <corentincj@iksaif.net>
Cc: Karol Kozimor <sziwan@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-24 00:14:51 -05:00
Mattia Dongili
528809c35f sony-laptop: enumerate rfkill devices using SN06
SN06 makes sure we get back a longer buffer which seems to be necessary
going forward as the SNC devices describes more and more devices (or
features more precisely). Moreover SN06 should be called with only the
descriptor offset to make sure we hit the rfkill controlling function
(F124 or F135) with a 0 argument to get a full list of features.

Signed-off-by: Mattia Dongili <malattia@linux.it>
Tested-by: Miguel Rodríguez Pérez <miguelrp@gmail.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-23 22:58:47 -05:00
Mattia Dongili
d5a664a311 sony-laptop: rfkill support for newer models
Vaio Type X and possibly other new models use F135 as the radio
frequency controlling function attached to the SNC device. In the
indexed table this corresponds to 0x0135 (surpise!).

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-23 22:58:46 -05:00
Jonathan Woithe
3b1c37cab3 fujitu-laptop: fix tests of acpi_evaluate_integer() return value
Fix tests on return value from acpi_evaluate_integer().  Based on a patch by
Roel Kluin <roel.kluin@gmail.com> and incorporating suggestions from Len
Brown <lenb@kernel.org>.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Jonathan Woithe <jwoithe@physics.adelaide.edu.au>
Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-23 02:24:32 -05:00
Stefani Seibold
7acd72eb85 kfifo: rename kfifo_put... into kfifo_in... and kfifo_get... into kfifo_out...
rename kfifo_put...  into kfifo_in...  to prevent miss use of old non in
kernel-tree drivers

ditto for kfifo_get...  -> kfifo_out...

Improve the prototypes of kfifo_in and kfifo_out to make the kerneldoc
annotations more readable.

Add mini "howto porting to the new API" in kfifo.h

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold
e64c026dd0 kfifo: cleanup namespace
change name of __kfifo_* functions to kfifo_*, because the prefix __kfifo
should be reserved for internal functions only.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold
c1e13f2567 kfifo: move out spinlock
Move the pointer to the spinlock out of struct kfifo.  Most users in
tree do not actually use a spinlock, so the few exceptions now have to
call kfifo_{get,put}_locked, which takes an extra argument to a
spinlock.

Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:56 -08:00
Stefani Seibold
4546548789 kfifo: move struct kfifo in place
This is a new generic kernel FIFO implementation.

The current kernel fifo API is not very widely used, because it has to
many constrains.  Only 17 files in the current 2.6.31-rc5 used it.
FIFO's are like list's a very basic thing and a kfifo API which handles
the most use case would save a lot of development time and memory
resources.

I think this are the reasons why kfifo is not in use:

 - The API is to simple, important functions are missing
 - A fifo can be only allocated dynamically
 - There is a requirement of a spinlock whether you need it or not
 - There is no support for data records inside a fifo

So I decided to extend the kfifo in a more generic way without blowing up
the API to much.  The new API has the following benefits:

 - Generic usage: For kernel internal use and/or device driver.
 - Provide an API for the most use case.
 - Slim API: The whole API provides 25 functions.
 - Linux style habit.
 - DECLARE_KFIFO, DEFINE_KFIFO and INIT_KFIFO Macros
 - Direct copy_to_user from the fifo and copy_from_user into the fifo.
 - The kfifo itself is an in place member of the using data structure, this save an
   indirection access and does not waste the kernel allocator.
 - Lockless access: if only one reader and one writer is active on the fifo,
   which is the common use case, no additional locking is necessary.
 - Remove spinlock - give the user the freedom of choice what kind of locking to use if
   one is required.
 - Ability to handle records. Three type of records are supported:
   - Variable length records between 0-255 bytes, with a record size
     field of 1 bytes.
   - Variable length records between 0-65535 bytes, with a record size
     field of 2 bytes.
   - Fixed size records, which no record size field.
 - Preserve memory resource.
 - Performance!
 - Easy to use!

This patch:

Since most users want to have the kfifo as part of another object,
reorganize the code to allow including struct kfifo in another data
structure.  This requires changing the kfifo_alloc and kfifo_init
prototypes so that we pass an existing kfifo pointer into them.  This
patch changes the implementation and all existing users.

[akpm@linux-foundation.org: fix warning]
Signed-off-by: Stefani Seibold <stefani@seibold.net>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-22 14:17:55 -08:00