In my HP Folio 13 laptop with Ubuntu 13.04 the brightness control works with the slider in the system Brightness & Lock settings, but the brightness function keys don't. Also, the brightness level is set to maximum on every boot.
Is there a way to make them work and make the system keep the brightness level set in the previous session?
Some information about my laptop concering this issue:
ls /sys/class/backlight
intel_backlight
ls /sys/class/backlight/*/brightness
/sys/class/backlight/intel_backlight/brightness
lspci | grep -i vga
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09)
uname -a
Linux folio13 3.8.0-19-generic #29-Ubuntu SMP Wed Apr 17 18:16:28 UTC 2013 x86_64 GNU/Linux
Best Answer
Guys it worked for me with this setting in
/etc/default/grub:Yep, this is empty value for acpi_osi...
Don't forget to do
sudo update-gruband restart after you edit the/etc/default/grubfile.