Red Hat Bugzilla – Bug 845077
Dell XPS 13: Backlight Brightness Controls Not Working
Last modified: 2013-11-08 05:41:42 EST
Description of problem:
Brightness controls on Dell XPS 13 don't work.
There's a patch set available at http://lists.freedesktop.org/archives/intel-gfx/2012-June/018030.html which solves the issue (tested with a locally rebuilt kernel RPM which includes said stack of patches).
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Press Fn+F4 or Fn+F5 to decrease/increase the panel brightness;
Panel brightness doesn't change (although Gnome shows the display brightness popup).
Panel brightness should increase and decrease as I press the buttons.
It is possible to work-around the problem by creating an acpid event file like the following:
Created attachment 601782 [details]
[PATCH 1/4] drm/i915: pnv has a backlight polarity control bit, too
Created attachment 601783 [details]
[PATCH 2/4] drm/i915: clear up backlight #define confusion on gen4+
Oh wait... looks like these patches were merged in 3.5.0. I'm rebuilding my customized kernel RPMs (which include other patches for my Dell XPS 13) in order to test it.
I'm now running kernel-3.6.0-0.rc0.git9.3.fc18.x86_64 and the issue seems to be fixed.
Can the patch-set be backported to F-16 and F-17 kernels?
The 3.5 kernels are coming to F16 soon, we have one major issue that F17 users are experiencing that we need to get fixed first.
With kernel 3.10 and 3.11 (actually until fedora kernel 3.11.7) it doesn't work for anymore. See Bug Report 1028383 and Bug Report 995782.
Comment 6 was tried with Fedora 20 alpha