I cannot control brightness with hardware buttons, nor with DE (lightdm) brightness slider.
I cannot control using any packages (xbacklight …). -xbacklight is changing some values but without effect.
I can control them the following way:
echo 250 > /sys/class/backlight/radeon_bl0/brightness
What I tried: everything in this https://forum.antergos.com/topic/2815/can-t-adjust-screen-brightness/5
What is propably the cause: systemctl --failed output:
UNIT LOAD ACTIVE SUB DESCRIPTION ● [email protected]:acpi_video0.service loaded failed failed Load/Save Screen Backlight Brightness of backlight:acpi_video0
I know that I can set my keyboard brightness control to echo values, but I would really like this error to dissapear and to control it through xbacklight and DE slider.
One interesting fact: lightdm’s night mode does work precise even with DE button.
Another: Sound hardware buttons work, they even show an icon popup with slider.
Another: External monitor modes hardware button works pretty good.
Another: I had Ubuntu for some months and brigthness hard. buttons were working in Gnome and Unity.
Can someone help me set the PC to control it as it should?
Graphics: ATI Radeon r5 graphics (drivers installed - even some additional for games) , AMD Mullins
Base system: Antergos Linux 64-bit
All packages and system are up to date
Kernel version: 4.12.12-1-ARCH
Thanks in advance. If more details needed, please ask.