Commit 25294e9f authored Aug 28, 2014 by Hans de Goede Committed by Rafael J. Wysocki Sep 02, 2014

ACPI / video: Fix use_native_backlight selection logic

Commit 751109aa ("ACPI / video: Change the default for
video.use_native_backlight to 1") has changed the default for
use_native_backlight from 0 to 1, but instead of changing
use_native_backlight_dmi to true, and leaving use_native_backlight_param at -1,
it has changed use_native_backlight_param to 1.

This causes acpi_video_use_native_backlight() to always think that a value was
specified through the param, making it impossible to add a dmi based quirk
to force 0 now that the default is 1.

This fixes this by restoring the use_native_backlight_param default to -1, and
instead setting the use_native_backlight_dmi default to true.

Fixes: 751109aa (ACPI / video: Change the default for video.use_native_backlight to 1)
Cc: 3.16+ <stable@vger.kernel.org> # 3.16+
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent 69e273c0

drivers/acpi/video.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -82,9 +82,9 @@ module_param(allow_duplicates, bool, 0644);
		* For Windows 8 systems: used to decide if video module
		* should skip registering backlight interface of its own.
		*/
		static int use_native_backlight_param = 1;
		static int use_native_backlight_param = -1;
		module_param_named(use_native_backlight, use_native_backlight_param, int, 0444);
		static bool use_native_backlight_dmi = false;
		static bool use_native_backlight_dmi = true;

		static int register_count;
		static struct mutex video_list_lock;

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