Hi guys, After update from kernel 3.0.8 to 3.1 I encounter the following problem. When power saving turns off the back light, key/mouse activity does not turn it back on. I can turn it back on by pressing the "brightness++" key. The following sequence also leaves the backlight off: xset dpms force off; xset dpms force on while the next, conceptually similar sequence, reenables it just fine: xbacklight -set 0; xbacklight -set 100 In each case the problem only manifests itself on the laptop's internal panel. The backlight of a second display panel connected to the mini DVI port (using a VGA converter) is turned back on in each case. My graphics card is a 00:02.0 VGA compatible controller: Intel Corporation Mobile GM965/GL960 Integrated Graphics Controller (primary) (rev 03) which is driven by i915. The problem is perfectly reproducible. Bisection points out that first bad commit is aaa6fd2a004147bf32fce05720938236de3361d9 Author: Matthew Garrett 2011-08-12 11:11:33 Committer: Keith Packard 2011-08-15 20:10:25 Parent: 13d83a672e9bbd52ae82c2f611dfd845a957e8b4 (drm/i915: split out PCH refclk update code) Branches: linux-3.1.y, master, remotes/origin/linux-3.1.y, remotes/origin/master Follows: v3.1-rc1 Precedes: v3.1-rc3 Not all systems expose a firmware or platform mechanism for changing the backlight intensity on i915, so add native driver support. I am running Debian testing on a MacBook 4,1 with the following X tools. xorg 1:7.6+9 xserver-xorg 1:7.6+9 xserver-xorg-core 2:1.11.1.901-2 xserver-xorg-input-all 1:7.6+9 xserver-xorg-input-evdev 1:2.6.0-2+b2 xserver-xorg-input-synaptics 1.4.1-1+b1 xserver-xorg-video-intel 2:2.16.0-1 dmesg, lspci and .config attached. I hope this information is helpful in sorting out the problem. If not, don't hesitate to indicate additional information that would be relevant. With kind regards, Wouter Koolen