On Mon, 3 Sep 2012 16:25:12 +0300, Jani Nikula <jani.nikula at intel.com> wrote: > Previously intel_panel_setup_backlight() would create a sysfs backlight > interface with max brightness of 1 if it was unable to figure out the max > backlight brightness. This rendered the backlight interface useless. > > Do not create a dysfunctional backlight interface to begin with. > > Signed-off-by: Jani Nikula <jani.nikula at intel.com> Reviewed-by: Chris Wilson <chris at chris-wilson.co.uk> > --- > > See https://bugzilla.redhat.com/show_bug.cgi?id=752595 > > There's still a bug somewhere in the userspace as well; it should always > prefer the platform backlight interface over the raw one. This patch might > have the effect of hiding that particular userspace issue, but we shouldn't > be exporting a backlight interface that's useless no matter what. It was fixed. UXA uses a hardcoded set of preferred platform drivers, SNA looks at all the backlights under /sys/class/backlight and sorts them by type. We still have the issue of multi-panel or just multiple backlight interfaces and choosing the wrong one randomly. libbacklight's idea was to expose some more details through the kernel to be able to link device + connector to a particular backlight interface. However, userspace has the Option "Backlight" for fine tuning. -Chris -- Chris Wilson, Intel Open Source Technology Centre
