On mar., 2013-09-17 at 17:23 +0800, Aaron Lu wrote:
v1 has the subject of "Rework ACPI video driver" and is posted here: http://lkml.org/lkml/2013/9/9/74 Since the objective is really to fix Win8 backlight issues, I changed the subject in this version, sorry about that.
This patchset has three patches, the first introduced a new API named backlight_device_registered in backlight layer that can be used for backlight interface provider module to check if a specific type backlight interface has been registered, see changelog for patch 1/3 for details. Then patch 2/3 does the cleanup to sepeate the backlight control and event delivery functionality in the ACPI video module and patch 3/3 solves some Win8 backlight control problems by avoiding register ACPI video's backlight interface if: 1 Kernel cmdline option acpi_backlight=video is not given; 2 This is a Win8 system; 3 Native backlight control interface exists.
I've tested this on my x230 (using pure UEFI with CSM disabled). As far as I can tell, it works as I would expect:
- brightness keys work in initramfs, in console after boot, in lightdm prompt and in Xfce (wether or not xfce4-power-manager is running).
I don't have brightness notifications (from xfce4-power-manager) but I don't usually need them so I'm fine with that.
Regards,