In my case this turned out to be a known bug with the "modesetting" graphics driver, a fix for which would be available in linux 4.11 earliest: https://bugs.freedesktop.org/show_bug.cgi?id=96572 Perhaps xbacklight works out-of-the-box on Ubuntu 17.10 :)
Googling around suggests Ubuntu 16.04 switched to modesetting driver recently (but I could not find definitive info on this). Switching back to the intel driver fixed the issue for me: I edited the file /usr/share/X11/xorg.conf.d/10-intel-modesetting.conf to load the "intel" driver instead of "modesetting" driver. ** Bug watch added: freedesktop.org Bugzilla #96572 https://bugs.freedesktop.org/show_bug.cgi?id=96572 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1638136 Title: xbacklight not working in ubuntu 16.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xbacklight/+bug/1638136/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
