| commit | efaa14c7e981bdf8d3c8d39d3ed12bdc60faabb8 | [log] [tgz] |
|---|---|---|
| author | Aaron Lu <[email protected]> | Tue Jul 16 13:08:05 2013 +0800 |
| committer | Rafael J. Wysocki <[email protected]> | Thu Jul 18 02:08:16 2013 +0200 |
| tree | e393015f17feca2feec73e1a43d50967c4eb6b73 | |
| parent | 8c5bd7adb2ce47e6aa39d17b2375f69b0c0aa255 [diff] |
ACPI / video: no automatic brightness changes by win8-compatible firmware Starting from win8, MS backlight control driver will set bit 2 of the parameter of control method _DOS, to inform firmware it should not perform any automatic brightness changes. This mostly affects hotkey notification deliver - if we do not set this bit, on hotkey press, firmware may choose to adjust brightness level instead of sending out notification and doing nothing. So this patch sets bit 2 when calling _DOS so that GUIs can show the notification window on hotkey press. This behavior change is only necessary for win8 systems. The MS document on win8 backlight control is here: http://msdn.microsoft.com/en-US/library/windows/hardware/jj159305 References: https://bugzilla.kernel.org/show_bug.cgi?id=52951 References: https://bugzilla.kernel.org/show_bug.cgi?id=56711 Reported-by: Micael Dias <[email protected]> Reported-by: Dan Garton <[email protected]> Reported-by: Bob Ziuchkovski <[email protected]> Signed-off-by: Aaron Lu <[email protected]> Signed-off-by: Rafael J. Wysocki <[email protected]>