So, I installed Endeavour OS and had minimal if not zero backlight bug and I tried to self-diagnose the issue.
Here’s a description of the problem
- Brightness control on the software side works as expected
- But the F2/F3 keys (laptop brightness hotkeys) result in inverted behavior (ie 5% brightness looks much brighter than 95%)
- Kernel parameter changes results in max brightness but introduces lag
I insist that the software side is changing as expected because
/sys/class/backlight/amdgpu_bl1/brightness changes and there is a relative change in perceived brightness also.
- Linux Kernel 6 (latest kernel)
- Nvidia RTX 3050Ti + Nvidia Drivers
- AMD Ryzen 5600H
- HP Victus 15
So, I did some research and tried to fix this using kernel parameters and here are the results of the different combinations I have tried.
amdgpu.backlight=0 > max brightness, but stuck at 100% also heavy UI lag
acpi_backlight=video > very low brightness, inverted controls and max brightness is too low
amdgpu.backlight=1 > max brightness stuck at 100% and heavy UI lag
amdgpu.backlight=0 nvidia_drm.modeset=1 > back to low brightness and inverted controls, UI lag has disappeared though
Is this a hardware issue or a kernel issue, but I am on the latest kernel. Also, secure boot is disabled if that’s relevant. Will masking one of the GPU systemd services work?
If anyone with similar device who has found out a fix for this it will be much appreciated.