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Commit c2c78905 authored by Zhao Yakui's avatar Zhao Yakui Committed by Andi Kleen
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ACPI: Ignore _BQC object when registering backlight device 

According to acpi spec , the objectes of  _BCL and _BCM are required if
integrated LCD is present and supports brightness level and the _BQC is
the optional object. So the _BQC object will be ignored when the backlight
device is registered.
At the same time when there is no _BQC object, the current brightness will be
set to the maximum.

http://bugzilla.kernel.org/show_bug.cgi?id=10206



Signed-off-by: default avatarZhao Yakui <yakui.zhao@intel.com>
Signed-off-by: default avatarZhang Rui <rui.zhang@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@linux.intel.com>
parent 4a5e3638

drivers/acpi/video.c

+12 −2
Original line number Diff line number Diff line
@@ -741,7 +741,7 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) 


	max_level = acpi_video_init_brightness(device);



	if (device->cap._BCL && device->cap._BCM && device->cap._BQC && max_level > 0){

	if (device->cap._BCL && device->cap._BCM && max_level > 0) {

		int result;

		static int count = 0;

		char *name;
@@ -753,7 +753,17 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device) 
		device->backlight = backlight_device_register(name,

			NULL, device, &acpi_backlight_ops);

		device->backlight->props.max_brightness = device->brightness->count-3;

		device->backlight->props.brightness = acpi_video_get_brightness(device->backlight);

		/*

		 * If there exists the _BQC object, the _BQC object will be

		 * called to get the current backlight brightness. Otherwise

		 * the brightness will be set to the maximum.

		 */

		if (device->cap._BQC)

			device->backlight->props.brightness =

				acpi_video_get_brightness(device->backlight);

		else

			device->backlight->props.brightness =

				device->backlight->props.max_brightness;

		backlight_update_status(device->backlight);

		kfree(name);