On 06/17/2013 07:27 PM, Rafael J. Wysocki wrote: > On Monday, June 17, 2013 09:01:10 AM Aaron Lu wrote: >> 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. >> >> The MS document on win8 backlight control is here: >> http://msdn.microsoft.com/en-US/library/windows/hardware/jj159305 >> >> This patch solves problem for ASUS N56VZ and ASUS N56VJ, both for >> notification delivery and for brightness control. >> >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=52951 >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=56711 >> Reported-and-tested-by: Micael Dias <kam1kaz3@xxxxxxxxx> >> Reported-and-tested-by: Dan Garton <dan.garton@xxxxxxxxx> >> Reported-and-tested-by: Bob Ziuchkovski <bob.ziuchkovski@xxxxxxxxx> >> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> > > OK, do we need that in -stable and if so, which ones? Perhaps only for new kernels, since 3.7 and 3.8 are EOL-ed, so just for 3.9. I don't think older kernels need change the behavior. Thanks, Aaron > > Rafael > > >> --- >> drivers/acpi/video.c | 4 ++-- >> 1 file changed, 2 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c >> index b8299f2..f8fa541 100644 >> --- a/drivers/acpi/video.c >> +++ b/drivers/acpi/video.c >> @@ -1543,12 +1543,12 @@ static int acpi_video_bus_put_devices(struct acpi_video_bus *video) >> >> 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, 1); >> } >> >> 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, 0); >> } >> >> static void acpi_video_bus_notify(struct acpi_device *device, u32 event) >> -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
