Re: [gentoo-user] Re: Backlight problems

[Mark Knecht <markknecht@gmail.com>]

On Fri, Mar 16, 2012 at 10:58 AM, Grant <emailgrant@gmail.com> 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.
>
> I tried the latest Kubuntu and Ubuntu LiveCDs via unetbootin but the
> backlight behavior is the same as with Gentoo.  Please let me know if
> anyone has any ideas on this.
>
> - Grant
>

Grant,
   Sorry I missed this thread earlier. I've got an Asus 17" laptop
that I've been trying unsuccessfully to get the keyboard backlighting
to work correctly for weeks (maybe months - I no longer remember how
long) On my machine I get keyboard backlighting when I boot the
machine, but if I turn off the lights with the switch on the machine I
cannot so far turn them back on by any means.

   On this machine xbacklight -get responds that nothing has backlight
properties so I've clearly got some configuration issues.

   As for the kernel I'm using vanilla-sources-3.2.10 so I don't think
there's a lot that is newer than that.

   I don't care much about screen backlighting but keyboard
backlighting is important to me.

- Mark