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| author | Aaron Lu <aaron.lu@intel.com> | 2014-07-07 15:43:51 +0800 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2014-07-07 23:38:05 +0200 |
| commit | 0b9f7d93ca6109048a4eb06332b666b6e29df4fe (patch) | |
| tree | dafe5099689b7a18e12ef1cf98ecafd89ab52235 /drivers/acpi/video.c | |
| parent | cd3de83f147601356395b57a8673e9c5ff1e59d1 (diff) | |
| download | linux-0b9f7d93ca6109048a4eb06332b666b6e29df4fe.tar.gz linux-0b9f7d93ca6109048a4eb06332b666b6e29df4fe.tar.bz2 linux-0b9f7d93ca6109048a4eb06332b666b6e29df4fe.zip | |
ACPI / i915: ignore firmware requests for backlight change
Some Thinkpad laptops' firmware will initiate a backlight level change
request through operation region on the events of AC plug/unplug, but
since we are not using firmware's interface to do the backlight setting
on these affected laptops, we do not want the firmware to use some
arbitrary value from its ASL variable to set the backlight level on
AC plug/unplug either.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=76491
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77091
Reported-and-tested-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>
Reported-and-tested-by: Anton Gubarkov <anton.gubarkov@gmail.com>
Signed-off-by: Aaron Lu <aaron.lu@intel.com>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/video.c')
| -rw-r--r-- | drivers/acpi/video.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c index fb9ffe9adc64..5bb1278e9324 100644 --- a/drivers/acpi/video.c +++ b/drivers/acpi/video.c @@ -241,13 +241,14 @@ static bool acpi_video_use_native_backlight(void) return use_native_backlight_dmi; } -static bool acpi_video_verify_backlight_support(void) +bool acpi_video_verify_backlight_support(void) { if (acpi_osi_is_win8() && acpi_video_use_native_backlight() && backlight_device_registered(BACKLIGHT_RAW)) return false; return acpi_video_backlight_support(); } +EXPORT_SYMBOL_GPL(acpi_video_verify_backlight_support); /* backlight device sysfs support */ static int acpi_video_get_brightness(struct backlight_device *bd) |