display backlight is somewhat broken

Message

Rion · Post by **Rion** » Tue Sep 18, 2018 8:38 am

Hi

After some recent updates something is wrong with my laptop's display. As usually it's turned off by timeout but now I have to switch to terminal (cctrl+alt+f1) and back to turn it on.
Also functional keys for display brightness do not work anymore.

Does anyone have any idea?

Clevo p170em

UPDATE:
The problem is related to kernel update from 4.14 to 4.18.
Gotta compare configs.

Ant P. · Post by **Ant P.** » Tue Sep 18, 2018 10:58 pm

Don't have a solution, but I can confirm you're not the only one at least. Running i915 and 4.18.5 here.

Anon-E-moose · Post by **Anon-E-moose** » Tue Sep 18, 2018 11:14 pm

Did your fn key work directly before?

I have an acer laptop and had to use the acpi functions for some of the fn keys, including brightness, in my case.

Rion · Post by **Rion** » Thu Sep 27, 2018 8:57 pm

Just in case. Reproduced on old kernel too. So the problem is not in kernel. and maybe I misinterpreted Fn keys behaviour. In any case they work fine with 4.14.65 kernel, not sure about others.

So what really happens from my last observations..

I use xfce now. and there are 3 timers for display in its power settings.
The first timer doesn't have any effect
Second one (stand by mode) disables my display the way requiring switching to terminal
Third one (power off) - fixes the display so it again can light up just by mouse click.

UPDATE:
that's strange. Just disabled and enabled back display power management in xfce settings and it seems it works properly now.