On Monday, June 17, 2013 11:01:50 PM Aaron Lu wrote: > 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. Well, 3.8 has become a long-term at least ... Thanks, 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) > >> > -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. -- 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
