Same issue with GTX 980M on Ubuntu 16.04, even with latest NVIDIA drivers (367.27).
I described this on NVIDIA forums: https://devtalk.nvidia.com/default/topic/942337/linux/backlight-brightness-not-hooked-to-acpi-events-ubuntu-16-04-/ I manually fixed it by created an acpid event handler, however in my solution, it only works when changing the brightness with the Fn-keys, but not by changing /sys/class/backlight/acpi_video0/brightness value. Link Dupont's fix works better (but I didn't use video.use_native_backlight=1 on GRUB_CMDLINE_LINUX as he said). By the way, the link to his solution is dead. This one works: http://sub- pop.net/post/fedora-23-on-system76-oryx-pro/ -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1518473 Title: /sys/class/backlight/acpi_video0/brightness is broken To manage notifications about this bug go to: https://bugs.launchpad.net/system76/+bug/1518473/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
