Hey, I hope someone can help me.
Problem:
When I wake my PC from suspend, my monitor is always set down to 30% brightness for some reason.
These are the brightness settings of the monitor itself, which can only be accessed via the monitor settings using the buttons on the monitor. I do not mean the brightness settings of my desktop environment. These are still set to 100%, even though the monitor is darker.
The problem also arises in a second case. When I lower the brightness in the brightness control of my DE, my monitor brightness is also lowered in the monitor settings down to 30% again. I can then no longer increase the brightness in the DE settings, because 100% in the DE now equals 30% in the monitor. So if I set the brightness to 50% in the DE for example, this is 50% of the 30% set in the monitor. So actually only 15% in real terms
I hope I was able to explain the problem clearly. Please ask if you don’t understand something. It’s really annoying because I need to turn up my screen brightness with the Buttons on the Monitor every single time I wake up my PC.
Technical data:
- Nobara Linux 41 (Based on Fedora)
- KDE Plasma 6.3.3
- Wayland
- Desktop PC. So a external monitor. Not a laptop monitor.
- I have a 2nd monitor on which this does not happen.
I saw this problem for the first time yesterday. Run
dmesg
to look for errors from the kernel, for me I hadamdgpu 0000:03:00.0: [drm] *ERROR* dc_dmub_srv_log_diagnostic_data: DMCUB error - collecting diagnostic data
. I took this to mean that my system couldn’t communicate with the monitor to change brightness anymore. When my system is idle, it first dims the monitor before turning it off, so when I wake it back up it’s stuck on low brightness like this. Simply turning my monitor off and back on seemed to fix it.What kernel are you on?
I think this is somewhat of a known issue with Plasma 6. Happens intermittently to me as well. But seemingly the latest versions should have it fixed
latest versions should have it fixed
Well fuck me, I guess xD I had this problem since probably 3 weeks and tried so much shit and yes I also updated many times. BUT NOW when I finally make a post about it, the newest update I just made fixed it. So yea. All working fine again. ✅
Haha, nice! Happy to hear that! But sometimes it do be like that
I’ve got a relatively new Fedora install and I think I’ve seen this too - not had time to fully investigate, but have found on occasion if I leave it for a day the monitor brightness has wound down.
It might have to do with your I2C? Install
ddcutil
and tell us what it detectsDisplay 2 is the one with the Problem