On 07/16/2013 10:39 PM, Micael wrote: > Working fine here. Thanks for your testing! -Aaron > > > On Tue, Jul 16, 2013 at 6:08 AM, Aaron Lu <aaron.lu@xxxxxxxxx> 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. 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 >> >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=52951 >> Buglink: https://bugzilla.kernel.org/show_bug.cgi?id=56711 >> Reported-by: Micael Dias <kam1kaz3@xxxxxxxxx> >> Reported-by: Dan Garton <dan.garton@xxxxxxxxx> >> Reported-by: Bob Ziuchkovski <bob.ziuchkovski@xxxxxxxxx> >> Signed-off-by: Aaron Lu <aaron.lu@xxxxxxxxx> >> --- >> Apply on top of: >> https://patchwork.kernel.org/patch/2812951/ (expose OSI version) >> https://patchwork.kernel.org/patch/2827793/ (win8 video quirk) >> >> Micael, Dan and Bob, >> Please give the patch a test if possible, thanks. >> >> v2: Make the behavior change only for win8 systems; use the newly added >> function acpi_video_backlight_quirks as the condition check for win8. >> >> drivers/acpi/video.c | 10 ++++++++-- >> 1 file changed, 8 insertions(+), 2 deletions(-) >> >> diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c >> index 01b1a25..bc2954b 100644 >> --- a/drivers/acpi/video.c >> +++ b/drivers/acpi/video.c >> @@ -1534,14 +1534,20 @@ 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) >> -- >> 1.8.3.2.10.g43d11f4 >> > > > -- 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
