I found the cause of the problem, which is that for some reason update- manager starts a gnome-power-manager instance as root, which then is responsable for the backlight change.
** Summary changed: - update-manager sets display brightness to 100% + sudo update-manager starts a new gnome-power-manager as root -- sudo update-manager starts a new gnome-power-manager as root https://bugs.launchpad.net/bugs/370466 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
