Re: [gentoo-user] Re: Backlight problems

[Grant]

>> 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