Comment 8 for bug 503577

I am trying to summarise some info take from other bugs here.

In bug #230421, we learn that the following changed in the acpi-support package in Ubuntu 9.10:
  * Drop events/video_brightness{down,up}, video_brightness{up,down}.sh: at
    least some platforms that use these ACPI sequences are seeing them
    correctly translated to input events, so those users will see duplicate
    events unless we drop them. LP: #178860.

Mike, can you please run the 'acpi_listen' command, and report here any output produced when you press the brightness keys?

This bug also suggest to look at the https://wiki.ubuntu.com/Hotkeys/Troubleshooting page.

Bug #385723 seems the general missing backlight control for Linux kernel.

Bug #320874, is very interesting, and was fixed in kernel 2.6.29:
http://bugzilla.kernel.org/show_bug.cgi?id=12249 (reading fast, could be BIOS related).

Bug #388216 (because KMS)
What I call sub-bug 3, (brightness not saved) is in bug #35223, and they did fill a bug directly to gnome project:
https://bugzilla.gnome.org/show_bug.cgi?id=335673

Bug #131650, brightness keys not working on Vaio SZ-140p.
Sony Vaio have LOTS of bug reports...

Bug #223954 (brightness controls still has major bugs) (mostly about going back to 100% when opening lid), asked to do:
Thanks for your report but we need more information about your bug. Please, run gnome-power-bugreport.sh and gconftool -a /apps/gnome-power-manager/backlight.

Bug #406515, for Lenovo, but showing how to determine keycodes, also link to Lnux kernel bugs.

Ok, I'll stop there for now, just to show that there is many kernel issues going on around this.