On 05/04/2017 03:42 PM, Lars Noodén wrote:
> I'm having trouble adjusting the backlight on my LCD screen in RC 1 with
> XFCE4. No matter what I've tried so far, it stays where it is. With
> Ubuntu 16.04, things are pre-configured and it is just a matter of
> pressing the right function buttons. However, with Devuan Jessie RC 1
> the right commands are hard to figure out.
>
> Here is what I've tried so far to change the backlight intensity. None
> have any effect:
>
> $ xrandr --output default --brightness 0
> xrandr: Gamma size is 0.
>
> $ ls /sys/class/backlight/
>
> $ xgamma -gamma 0.9
> -> Red 1.000, Green 1.000, Blue 1.000
> <- Red 0.900, Green 0.900, Blue 0.900
>
> $ xbacklight
> No outputs have backlight property
>
> I've also tried adding "acpi_backlight=vendor" to the kernel boot options.
>
> What should I be looking at or trying so as to be able to increase or
> decrease the backlight?
>
> Regards,
> Lars
>
> PS. The RC1 installer is much improved for this notebook. It found
> the wireless, for example
>

It's with this kernel:

$ uname -s -r -v -m
Linux 3.16.0-4-amd64 #1 SMP Debian 3.16.43-2 (2017-04-30) x86_64

Any hints would be appreciated.

Regards,
Lars