Does this issue go away and brightness work again if you boot into the last kernel version?
** Tags added: kernel-da-key regression-update -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1395782 Title: brightness control To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1395782/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
