Another Gen 9 GPU that I have is not affected by this bug:
$ glxinfo | grep Device Device: Mesa DRI Intel(R) HD Graphics 515 (Skylake GT2) (0x191e) $ cat /proc/version_signature Ubuntu 5.4.0-12.15-generic 5.4.8
I can increase and decrease the brightness without any issues.
Another Gen 9 GPU that I have is not affected by this bug:
$ glxinfo | grep Device signature
Device: Mesa DRI Intel(R) HD Graphics 515 (Skylake GT2) (0x191e)
$ cat /proc/version_
Ubuntu 5.4.0-12.15-generic 5.4.8
I can increase and decrease the brightness without any issues.