>> 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.
That's a fine idea. The latest Gentoo minimal CD wouldn't boot this laptop so I used Kubuntu to install and I should do something like that for testing the backlight. Is there a consensus on which LiveCD is kept really up-to-date and works well across a lot of different hardware? - Grant
