Comment 36 for bug 363326

Thanks, Janis. The issue here is either that the laptop has a proprietary backlight control or the BIOS is slightly broken.

Just in case, can you try running the "current" mainline kernel from the instructions at <https://wiki.ubuntu.com/KernelTeam/MainlineBuilds>? This is just to ensure the problem's not specific to Ubuntu and not fixed already in the next release of the kernel. The keys may still not work, check /sys/class/backlight/ just to see if the kernel found anything.

If the mainline kernel doesn't work, then our best hope is to get upstream linux to work around a bug in the BIOS. If this is the case, please install acpidump and attach a dump here with the following commands:

sudo apt-get install acpidump
sudo acpidump -o acpidump.txt

I'll then try to take a look at the dump and determine if it's possible to workaround it.

I know all this is pretty involved, but at this point it's "let's fix a problem" instead of "let's find the bug", so you might help add a feature to linux if we're lucky. :)