buwie on ArchLinux forum pointed out a workaround, although setting the brightness via fn keys won’t work, it’s possible to set the brightness with xcalib by loading a icc generated from icc-brightness.
For instance, to generate a icc-brightness file:
icc-brightness 55 100,this will generate /tmp/brightness_55_100.icc,
which you can load with:
xcalib /tmp/brightness_55_100.icc
Finally, if you want more than one config you just have to generate the rest of the brightness icc files, probably with 5-10% as you wish, and then later you just run xcalib passing the file.
Also, If you’re using i3wm then you just load the expected icc file:
exec --no-startup-id xcalib ~/.brightness/brightness_55_100.icc
Regarding the kernel parameters, I’m still using:
i915.enable_dpcd_backlight=1 nvidia.NVreg_EnableBacklightHandler=0 nvidia.NVreg_RegistryDwords=EnableBrightnessControl=0