Bug#443111: laptop: can't set brightness from within X11

[Brice Goglin <Brice.Goglin@ens-lyon.org>]

Dirk Griesbach wrote:
> After upgrading from version 1.7.2-4 to 2.1.1-4 I can’t set the
> brightness with the buttons supposed to set the brightness on my FSC
> S7110. In VT I can but if I switch back to X11 the brightness is set to
> the highest level. I can change the brightness from within X11 if I echo
> the appropriate value to /proc/acpi/video/GFX0/LCD/brightness. But then
> after hitting the brightness control keys on my Laptop the brightness is
> switched to the brightest value available and nothing else happens. It’s
> switched to the highest value too if I set the brightness in VT and
> switch back to X11.
>   

You should probably use the xbacklight tool (xbacklight package) instead
of the brightness control keys. The latter might change things in the
back of the driver (through the BIOS), causing possible problems.

There are some problems with xbacklight though, for instance bug #438969.

> This doesn't happen if I downgrade to 1.7.2-4.
>   

Have you ever tried with previous releases of xserver-xorg-video-intel,
for instance 2.0.0 or 2.1.0?

Brice