3.13 i915 brightness settings broken when going from docked -> undocked

[Paul Bolle]

On Tue, 2014-02-25 at 10:05 +0200, Jani Nikula wrote:
> On Thu, 20 Feb 2014, Paul Bolle <pebolle at tiscali.nl> wrote:
> > On an (rather old) ThinkPad X41, which also uses i915, brightness
> > adjustments stopped working altogether in v3.14-rc1 (I haven't used its
> > docking station in the v3.14 release cycle). In v3.13.y things behave as
> > expected. So perhaps there's actually a more general problem here.
> 
> I presume different problems. Does the ThinkPad X41 have gen3 graphics?
> (See e.g. /sys/kernel/debug/dri/0/i915_capabilities) If yes, it might be
> https://bugs.freedesktop.org/show_bug.cgi?id=75001

Yes, it has "gen3" graphics (a 915GM). And applying your patch
"drm/i915: use backlight legacy combination mode also for
i915gm/i945/gm" on top of v3.14-rc5 fixes the issue on that ThinkPad
X41.

Thanks,


Paul Bolle