This still happens in 20.04 with Ideapad L340 81TR0003BR. The fix in my case is switching to to linux-oem-20.04b (linux- oem-20.04-edge should also work) and creating a Xorg configuration file that enables EnableBrightnessControl solved the issue, here's the full command:
cat <<EOF | sudo tee /usr/share/X11/xorg.conf.d/80-nvidia.conf > Section "Device" > Identifier "Device0" > Driver "nvidia" > VendorName "NVIDIA Corporation" > Option "RegistryDwords" "EnableBrightnessControl=1" > EndSection > EOF nvidia.EnableBrightnessControl=1 on the kernel command line did not work for me. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1863407 Title: Lenovo Ideapad L340 screen backlight stuck at maximum brightness To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1863407/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
