The workaround suggests that there's an interaction between the NVIDIA driver and another kernel module at play here. Presumably, adding the NVIDIA kernel modules to the initrd causes them to be loaded before the other module. Maybe video.ko, which registers its own brightness handler?
The modeswitch glitch should probably be tracked as a separate issue. Can somebody who is experiencing this glitch provide an example video? -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1905591 Title: no brightness control in {455,460} after update from 450 To manage notifications about this bug go to: https://bugs.launchpad.net/oem-priority/+bug/1905591/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs