Sorry, my previous comment #10 was incorrect. What worked again after the reinstall was just the notification bubble, but it did not actually change the brightness. I had to add the EnableBrightnessControl option again, to the new xorg.conf that was created during installation. After an X restart I now have the bubble and it actually works:
Section "Device" Identifier "Default Device" Option "NoLogo" "True" Option "RegistryDwords" "EnableBrightnessControl=1" EndSection -- You received this bug notification because you are a member of Ubuntu Desktop Bugs, which is subscribed to gnome-power-manager in Ubuntu. https://bugs.launchpad.net/bugs/726692 Title: Screen backlight adjustment stopped working on MacBook Pro 5,4 and other hardware -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs