On 03/04/2012 01:16 PM, Grant wrote: > On my just-released Dell XPS 13 Ultrabook, I can control the backlight > with 'xbacklight -set 0' and 'xbacklight -set 100'. Any other values > cause the screen to blink and flash. The keyboard backlight shortcuts > don't work unless I map them to xbacklight 0 and 100. Also xbacklight > doesn't work at all if I'm unplugged from AC. I've tried > acpi_osi=Linux and acpi_backlight=vendor in grub.conf. acpi_osi > doesn't seem to make any difference and xbacklight doesn't work at all > without acpi_backlight. Do I just need to wait for a newer kernel?
Does the gentoo install CD or a rescue CD give you any way to test the same backlight functions? If the backlight works correctly when running such a CD then listing the loaded kernel modules might give you a clue.
