https://bugzilla.suse.com/show_bug.cgi?id=1180591 https://bugzilla.suse.com/show_bug.cgi?id=1180591#c7 --- Comment #7 from Takashi Iwai <tiwai@suse.com> --- Thanks. Judging from the given information, it's nouveau and the backlight is controlled solely via ACPI video driver. It's a bit surprising that the control doesn't take any effect in ACPI while it's exposed... Maybe narrowing the regression range might help. There are many kernel packages available in my OBS repo, e.g. home:tiwai:kernel:5.4, home:tiwai:kernel:5.5, etc. Could you try installing those old kernels one by one, and check which kernel started showing the bad behavior? Before testing that, it would be safer to increase the number of installable kernels in /etc/zypp/zypp.conf. Edit the file and add more entries in the line defining "multiversion.kernels". -- You are receiving this mail because: You are the assignee for the bug.