Comment 25 for bug 1214148

Hi JenniferHodgon,

I had the same bug as you and I have just resolved it following these steps:

Creating the file /usr/share/X11/xorg.conf.d/80-backlight.conf and filling it with:

Section "Device"
    Identifier "Intel Graphics"
    Driver "intel"
    Option "AccelMethod" "sna"
    Option "Backlight" "intel_backlight" # use your backlight that works here
    BusID "PCI:0:2:0"
EndSection

Bassically, I have followed the steps described in the section "For the Intel HD Graphic Controllers" from https://wiki.ubuntu.com/Kernel/Debugging/Backlight (this link was reported by you, thanks ;) )

Good luck,
Carlos
Cheers