1 files changed, 8 insertions, 2 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index e9d4bb60c35c..c9fa4621ed25 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -1539,14 +1539,20 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video)
 
 /* acpi_video interface */
 
+/*
+ * Win8 requires setting bit2 of _DOS to let firmware know it shouldn't
+ * preform any automatic brightness change on receiving a notification.
+ */
 static int acpi_video_bus_start_devices(struct acpi_video_bus *video)
 {
-        return acpi_video_bus_DOS(video, 0, 0);
+        return acpi_video_bus_DOS(video, 0,
+                                  acpi_video_backlight_quirks() ? 1 : 0);
 }
 
 static int acpi_video_bus_stop_devices(struct acpi_video_bus *video)
 {
-        return acpi_video_bus_DOS(video, 0, 1);
+        return acpi_video_bus_DOS(video, 0,
+                                  acpi_video_backlight_quirks() ? 0 : 1);
 }
 
 static void acpi_video_bus_notify(struct acpi_device *device, u32 event)