You can install NVIDIA proprietary drivers, after installation and reboot you will be able to control brightness (this works for me). So I think this bug is related to open source driver for NVIDIA graphics cards.
-- 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/704544 Title: brightness keys don't work on HP Elitebook 8540p -- desktop-bugs mailing list desktop-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/desktop-bugs
