I have the same problem and the fix in comment #11 fixed it. I agree with comment #16. I join a copy of my dmesg and Xorg.0.log before and after the fix. I hope it will be useful.
** Attachment added: "dmesg and Xorg.0.log before and after the fix." https://bugs.launchpad.net/ubuntu/+source/nvidia-graphics-drivers-455/+bug/1905591/+attachment/5462682/+files/XorgLogs.zip -- 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
