As I mentioned here Ryzen 7 + GTX 1660Ti: blank screen on external outputs in Hybrid graphics mode:
Backlight control was working with kernel 5.9.1 and driver 455.23.
I am now on kernel 5.9.9 and driver 455.45.01 and it stopped working.
Tried reverting back to kernel 5.9.1 and drivers 455.23… but no luck. I’m not sure how to proceed since I cannot replicate my old configuration, and it just stopped working.
The laptop is in Discrete mode, with only the NVIDIA graphics card enabled, the integrated AMD gpu is disabled. In Windows everything works fine.
Are the new drivers disabling / ignoring the “RegistryDwords” “EnableBrightnessControl=1;” Xorg option?
There are many threads online discussing this, but none of the solutions work. This appears to be a widespread problem and it occurs in both Discrete and Hybrid graphics mode selected on the BIOS.
nvidia-bug-report.log.gz (448.4 KB)