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path: root/drivers/acpi/video.c
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2011-05-10treewide: fix a few typos in commentsJustin P. Mattock
- kenrel -> kernel - whetehr -> whether - ttt -> tt - sss -> ss Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-31Fix common misspellingsLucas De Marchi
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-28acpi: Remove sysfs_create_link from video driverMatthew Garrett
The acpi video driver attempts to explicitly create a sysfs link between the acpi device and the associated PCI device. However, we're now also doing this from the backlight core, which means that we get a backtrace caused by a duplicate file. Remove the code and leave it up to the backlight core. Reported-by: Jeff Chua <jeff.chua.linux@gmail.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Alessandro Suardi <alessandro.suardi@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22acpi: tie ACPI backlight devices to PCI devices if possibleMatthew Garrett
Dual-GPU machines may provide more than one ACPI backlight interface. Tie the backlight device to the GPU in order to allow userspace to identify the correct interface. Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Airlie <airlied@linux.ie> Cc: Alex Deucher <alexdeucher@gmail.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Tested-by: Sedat Dilek <sedat.dilek@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22backlight: add backlight typeMatthew Garrett
There may be multiple ways of controlling the backlight on a given machine. Allow drivers to expose the type of interface they are providing, making it possible for userspace to make appropriate policy decisions. Signed-off-by: Matthew Garrett <mjg@redhat.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: David Airlie <airlied@linux.ie> Cc: Alex Deucher <alexdeucher@gmail.com> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Zhang Rui <rui.zhang@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Jesse Barnes <jbarnes@virtuousgeek.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13Merge branch 'release' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6 * 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6: (59 commits) ACPI / PM: Fix build problems for !CONFIG_ACPI related to NVS rework ACPI: fix resource check message ACPI / Battery: Update information on info notification and resume ACPI: Drop device flag wake_capable ACPI: Always check if _PRW is present before trying to evaluate it ACPI / PM: Check status of power resources under mutexes ACPI / PM: Rename acpi_power_off_device() ACPI / PM: Drop acpi_power_nocheck ACPI / PM: Drop acpi_bus_get_power() Platform / x86: Make fujitsu_laptop use acpi_bus_update_power() ACPI / Fan: Rework the handling of power resources ACPI / PM: Register power resource devices as soon as they are needed ACPI / PM: Register acpi_power_driver early ACPI / PM: Add function for updating device power state consistently ACPI / PM: Add function for device power state initialization ACPI / PM: Introduce __acpi_bus_get_power() ACPI / PM: Introduce function for refcounting device power resources ACPI / PM: Add functions for manipulating lists of power resources ACPI / PM: Prevent acpi_power_get_inferred_state() from making changes ACPICA: Update version to 20101209 ...
2011-01-12Merge branch 'bugzilla-21212' into releaseLen Brown
2010-12-14ACPI video: introduce module parameter video.use_bios_initial_backlightZhang Rui
Introduce module parameter video.use_bios_initial_backlight. Some BIOSes claim they use the minimum backlight at boot, and this may bring dimming screen after boot. https://bugzilla.kernel.org/show_bug.cgi?id=21212 use video.use_bios_initl_backlight=0 to use the maximum backlight level after boot. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-12-14ACPI video: check cap._DDC flag before getting EDIDZhang Rui
cap._DDC is defined but never used. Check this flag now and don't try to get EDID for video output devices with this flag cleared. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-12-14ACPI video: remove output switching controlZhang Rui
Remove the ACPI video output switching control as it never works. With the patch applied, ACPI video driver still catches the video output notification, but it does nothing but raises the notification to userspace. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-11-16backlight: constify backlight_opsLionel Debroux
backlight_device_register has been expecting a const "ops" argument, and using it as such, since 9905a43b2d563e6f89e4c63c4278ada03f2ebb14. Let's make the remaining backlight_ops instances const. Inspired by hunks of the grsecurity patch, updated for newer kernels. Signed-off-by: Lionel Debroux <lionel_debroux@yahoo.fr> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-10-15ACPI video: remove deprecated procfs I/FZhang Rui
Remove the deprecated ACPI video driver procfs I/F, as stated in the changelog of commit 6e37c658aefa57c472b2dbf1de88dbd3c67cdb52 New sysfs I/F is available at /sys/class/backlight/ Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-08-15gcc-4.6: ACPI: fix unused but set variables in ACPIAndi Kleen
Some minor improvements in error handling, but overall it was mostly dead code. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
2010-08-15ACPI video: make procfs I/F depend on CONFIG_ACPI_PROCFSZhang Rui
Mark ACPI video driver procfs I/F deprecated, including: /proc/acpi/video/*/info /proc/acpi/video/*/DOS /proc/acpi/video/*/ROM /proc/acpi/video/*/POST /proc/acpi/video/*/POST_info /proc/acpi/video/*/*/info /proc/acpi/video/*/*/state /proc/acpi/video/*/*/EDID and /proc/acpi/video/*/*/brightness, because 1. we already have the sysfs I/F /sysclass/backlight/ as the replacement of /proc/acpi/video/*/*/brightness. 2. the other procfs I/F is not useful for userspace. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-05-28Merge branch 'misc-2.6.35' into releaseLen Brown
2010-05-20drivers/acpi: use kasprintfJulia Lawall
kasprintf combines kmalloc and sprintf, and takes care of the size calculation itself. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression a,flag; expression list args; statement S; @@ a = - \(kmalloc\|kzalloc\)(...,flag) + kasprintf(flag,args) <... when != a if (a == NULL || ...) S ...> - sprintf(a,args); // </smpl> [akpm@linux-foundation.org: don't change handling of `count'] Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
2010-04-19ACPI: Export EDID blocks to the kernelMatthew Garrett
The ACPI spec includes a provision for hardware to provide EDID via the ACPI video extension. In the KMS world it's necessary for a way to obtain this from within the kernel. Add a function that either returns the EDID for the provided ACPI display ID or the first display of the provided type. Also add support for ensuring that devices with legacy IDs are supported. Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-04-06Merge branches 'battery', 'bugzilla-14667', 'bugzilla-15096', ↵Len Brown
'bugzilla-15480', 'bugzilla-15521', 'bugzilla-15605', 'gpe-reference-counters', 'misc', 'pxm-fix' and 'video-random-key' into release
2010-04-06ACPI / PM: Move ACPI video resume to a PM notifierRafael J. Wysocki
There is a problem with the ACPI video resume routine that it's executed before the GPU that may be accessed by it. To fix this issue, move the ACPI video resume to a power management notifier, so that's executed after resuming all devices, including the GPU. Fixes https://bugzilla.kernel.org/show_bug.cgi?id=15096, which is a listed regression from 2.6.31. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Tested-by: Rafał Miłecki <zajec5@gmail.com> Acked-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-04-04ACPI: Don't send KEY_UNKNOWN for random video notificationsMatthew Garrett
I have a machine here that's sending 0xD1 notifications on the video device once every second or so. I have no idea why (it's a prototype, it may be broken), but sending KEY_UNKNOWN is unhelpful and results in the console becoming unusable. Let's not report keys unless we have something useful to say about them. Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-16backlight: Allow properties to be passed at registrationMatthew Garrett
Values such as max_brightness should be set before backlights are registered, but the current API doesn't allow that. Add a parameter to backlight_device_register and update drivers to ensure that they set this correctly. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2010-03-14Merge branches 'battery-2.6.34', 'bugzilla-10805', 'bugzilla-14668', ↵Len Brown
'bugzilla-531916-power-state', 'ht-warn-2.6.34', 'pnp', 'processor-rename', 'sony-2.6.34', 'suse-bugzilla-531547', 'tz-check', 'video' and 'misc-2.6.34' into release
2010-03-14ACPI video: Be more liberal in validating _BQC behaviourMatthew Garrett
Right now, if _BQC returns a value we don't understand we immediately invalidate it. Change this behaviour so we only invalidate it if it continues to give an invalid answer after we've already set a brightness. Signed-off-by: Matthew Garrett <mjg@redhat.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-28ACPI: replace acpi_integer by u64Lin Ming
acpi_integer is now obsolete and removed from the ACPICA code base, replaced by u64. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2010-01-20Merge branch 'bugzilla-13577-video' into releaseLen Brown
2009-12-30ACPI video: Prune dupe video devices, unless "video.allow_duplicates"Zhang Rui
Some buggy BIOS exports multiple ACPI video bus devices for the same VGA controller, and multiple backlight control methods as well. This messes up the ACPI video backlight control. http://bugzilla.kernel.org/show_bug.cgi?id=13577 With this patch applied, only the FIRST ACPI video bus device under a PCI device node is bind to ACPI video driver by default. If the first ACPI video bus device doesn't work well, we can use video.allow_duplicates=1 to go back to the old behavior. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30Merge branch 'video-error-case' into releaseLen Brown
2009-12-30ACPI video: correct error-handling codeZhang Rui
backlight_device_register may return an ERR_PTR value rather than a valid pointer. Problem found by Julia Lawall, properly fixed by Zhang Rui. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Acked-by: Julia Lawall <julia@diku.dk> Signed-off-by: Len Brown <len.brown@intel.com>
2009-12-30ACPI video: no warning message if "acpi_backlight=vendor" is usedZhang Rui
AML code always sends notifications to ACPI video device, even if we disable the ACPI backlight control by using boot option "acpi_backlight=vendor". In this case we should not print any warning message. http://bugzilla.kernel.org/show_bug.cgi?id=13671#c14 Sigend-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-10-28ACPI: clean up video.c boundary checks and typesArjan van de Ven
proc.c and video.c are a bit sloppy around types and style, confusing gcc for a new feature that'll be in 2.6.33 and will cause a warning on the current code. This patch changes if (foo + 1 > sizeof bar) into if (foo >= sizeof(bar)) which is more kernel-style. it also changes a variable in proc.c to unsigned; it gets assigned a value from an unsigned type, and is then only compared for > not for negative, so using unsigned is just outright the right type Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-10-13ACPI: video: Loosen strictness of video bus detection codeStefan Bader
BugLink: http://bugs.launchpad.net/bugs/333386 Currently a video bus device must (beside other criteria) define _DOD and _DOS methods to be considered a video device. Some broken BIOSes prevented working backlight control by only defining both for one (non-existing bus) and only _DOD for the rest. With this patch in place the other bus definitions were considered too and backlight control started to work again. Signed-off-by: Stefan Bader <stefan.bader@canonical.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-10-01const: constify remaining file_operationsAlexey Dobriyan
[akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-26Merge branch 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlightLinus Torvalds
* 'for-linus' of git://git.o-hand.com/linux-rpurdie-backlight: backlight: new driver for ADP5520/ADP5501 MFD PMICs backlight: extend event support to also support poll() backlight/eeepc-laptop: Update the backlight state when we change brightness backlight/acpi: Update the backlight state when we change brightness backlight: Allow drivers to update the core, and generate events on changes backlight: switch to da903x driver to dev_pm_ops backlight: Add support for the Avionic Design Xanthos backlight device. backlight: spi driver for LMS283GF05 LCD backlight: move hp680-bl's probe function to .devinit.text backlight: Add support for new Apple machines. backlight: mbp_nvidia_bl: add support for MacBookAir 1,1 backlight: Add WM831x backlight driver Trivial conflicts due to '#ifdef CONFIG_PM' differences in drivers/video/backlight/da903x_bl.c
2009-09-21backlight/acpi: Update the backlight state when we change brightnessMatthew Garrett
Trigger a status update when we change the brightness in the driver, thus allowing userspace to present appropriate UI. Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>
2009-09-19Merge branch 'video' into releaseLen Brown
Conflicts: drivers/acpi/video.c Signed-off-by: Len Brown <len.brown@intel.com>
2009-09-19Merge branch 'misc-2.6.32' into releaseLen Brown
Conflicts: drivers/pci/dmar.c Signed-off-by: Len Brown <len.brown@intel.com>
2009-09-19ACPI: linux/acpi.h should not include linux/dmi.hLen Brown
users of acpi.h that need dmi.h should include it directly. Signed-off-by: Len Brown <len.brown@intel.com>
2009-09-19Merge branch 'sfi-base' into releaseLen Brown
Conflicts: drivers/acpi/power.c Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-31ACPI video: work-around BIOS AML bug in _BQCZhang Rui
_BQC on some laptops returns an uninitialized value when it's invoked for the first time. Set the laptop to the maximum backlight level in this case. http://bugzilla.kernel.org/attachment.cgi?id=22675 Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-29ACPI: video - rename cdev to cooling_dev -- syntax onlyDmitry Torokhov
Cdev name is normally used for ether class devices or character devices so rename member to avoid confusion for casual reader of the code. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-29ACPI: video - fix potential crash when unloadingDmitry Torokhov
thermal_cooling_device_register() returns error encoded in a pointer when it fails in which case we need to explictly set device->cdev to NULL so we don't try to unregister it when unloading. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-29ACPI video: ignore buggy _BQCVladimir Serbinenko
_BQC doesn't return a value listed in _BCL method. http://bugzilla.kernel.org/show_bug.cgi?id=13511 ingore the buggy _BQC method in this case Signed-off-by: Vladimir Serbinenko <phcoder@gmail.com> Signed-off-by: Scott Howard <showard314@gmail.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-28ACPI: Move definition of PREFIX from acpi_bus.h to internal..hLen Brown
Linux/ACPI core files using internal.h all PREFIX "ACPI: ", however, not all ACPI drivers use/want it -- and they should not have to #undef PREFIX to define their own. Add GPL commment to internal.h while we are there. This does not change any actual console output, asside from a whitespace fix. Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-28ACPI: don't free non-existent backlight in acpi video moduleKeith Packard
acpi_video_put_one_device was attempting to remove sysfs entries and unregister a backlight device without first checking that said backlight device structure had been created. Signed-off-by: Keith Packard <keithp@keithp.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
2009-08-27ACPI: video: remove unneeded memsetsZhang Rui
device->cap and video->cap are zeroed initially so we don't need to clear them again. Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Len Brown <len.brown@intel.com>
2009-06-24Merge branches 'acerhdf', 'acpi-pci-bind', 'bjorn-pci-root', ↵Len Brown
'bugzilla-12904', 'bugzilla-13121', 'bugzilla-13396', 'bugzilla-13533', 'bugzilla-13612', 'c3_lock', 'hid-cleanups', 'misc-2.6.31', 'pdc-leak-fix', 'pnpacpi', 'power_nocheck', 'thinkpad_acpi', 'video' and 'wmi' into release
2009-06-23ACPI: video: DMI workaround broken Acer 7720 BIOS enabling display brightnessZhang Rui
http://bugzilla.kernel.org/show_bug.cgi?id=13121 Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-06-23ACPI: Add the reference count to avoid unloading ACPI video bus twiceZhao Yakui
Sometimes both acpi video and i915 driver are compiled as modules. And there exists the strict dependency between the two drivers. The acpi video bus will be unloaded in course of unloading the i915 driver. If we unload the acpi video driver, then the kernel oops will be triggered. Add the reference count to avoid unloading the ACPI video bus twice. The reference count should be checked before unregistering the acpi video bus. If the reference count is already zero, it won't unregister it again. And after the acpi video bus is already unregistered, the reference count will be set to zero. http://bugzilla.kernel.org/show_bug.cgi?id=13396 Signed-off-by: Zhao Yakui <yakui.zhao@intel.com> Acked-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>
2009-06-23Show the physical device node of backlight class device.Zhang Rui
Create symbol link from backlight class device to ACPI video device. More and more laptops are shipped with multiple ACPI video devices, while we export only one of them to userspace. With this patch applied, we can know which ACPI video device is used by "cat /sys/class/backlight/acpi_video0/device/path". Signed-off-by: Zhang Rui <rui.zhang@intel.com> Signed-off-by: Len Brown <len.brown@intel.com>