Originally Posted by kwizart
Note that the brighteness control worksforme with the same driver and a DELL 630.
So the root problem could be somewhere else. (ACPI ? Is there a bios update ?)
I have the lastes BIOS installed. Dell doesnt provide any VBIOS update soo far.
I tried add only the "acpi_osi=Linux" in the line with GRUB_CMDLINE_LINUX= (located in /etc/default/grub), without changing xorg.conf but this didnt work. I needed to explicitly declare "EnableBrightnessControl=1" to work.
Maybe this could be elsewhere since brightness control couldnt work with nouveau too.