Same issue on Lenovo ThinkPat P76. Brightness control was working before. $ uname -r 5.4.0-59-generic
$ lspci |grep -i vga 01:00.0 VGA compatible controller: NVIDIA Corporation TU104GLM [Quadro RTX 5000 Mobile / Max-Q] (rev a1) $ sudo lshw -c video *-display description: VGA compatible controller product: TU104GLM [Quadro RTX 5000 Mobile / Max-Q] vendor: NVIDIA Corporation physical id: 0 bus info: pci@0000:01:00.0 version: a1 width: 64 bits clock: 33MHz capabilities: pm msi pciexpress vga_controller bus_master cap_list rom configuration: driver=nvidia latency=0 resources: irq:197 memory:ed000000-edffffff memory:c0000000-cfffffff memory:d0000000-d1ffffff ioport:2000(size=128) memory:ee080000-ee0fffff Downgrade to 450 works for me too. -- 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 after update from 450 to 455 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