I am experiencing this problem now as well. I am running on a "sputnik" the 1080p version. kernel 3.8.0-23-generic . When I turn apci_backlight=vendor then I can adjust the brightness to either lowest or hightest using the /sys/class/backlight.../brightness interface. However, when I use the default options for grub (quite splash) it is not adjustable at all.
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/954661 Title: backlight brightness not adjustable by default on Dell XPS 13 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/954661/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs