[ltp] Backlight on X1C3 on Archlinux

[Robert Tomsick]

On Thu, Mar 26, 2015, at 10:00 AM, Kai Hendry wrote:
> Hi there,
> 
> My new Thinkpad X1C3 mostly works on Archlinux except for the backlight
> / brightness controls.
> http://natalian.org/archives/2015/02/18/Archlinux_on_a_Lenovo_X1C3/
> 
> I noticed systemd-backlight@backlight:intel_backlight.service. I think
> that's just to save the current value.
> 
> I think I have the latest thinkpad module running.
> http://ix.io/h7H
> 
> Still the brightness buttons don't work.
> 
> Should I just bind F5, F6 to xbacklight -dev 5 & xbacklight -inc 5
> respectively?
> 

AFAIK, the issue is that the X1C3 isn't fully supported by
thinkpad_acpi.  Or rather, it is, but thinkpad_acpi doesn't know that
yet. ;)

So on my box (admittedly running Fedora... but with a similar kernel) I
added the "force_load" option to force it to load... and viola! 
Brightness worked.

YMMV.

-Rob