Every driver release since 465.24.02 somehow broke backlight control (tested all the way to the new beta driver 470.42).
Any change to /sys/class/backlight/nvidia_0/brightness have no effect at all. Programs which monitor the screen brightness will reflect what it’s written in such file, but the screen’s backlight is stuck at 100%.
This has already been reported in another thread ( Laptop backlight control regression with 465.24.02 ), and it’s getting more and more annoying as time passes.
I’m attaching the output of nvidia-bug-report.sh:
nvidia-bug-report.log.gz (313.3 KB)