I can confirm that this still happens on 12.04 LTS. Adding the line to xorg.conf as suggested by Pierre Chifflier makes it work correctly. I'm using proprietary drivers too.
-- You received this bug notification because you are a member of Desktop Packages, which is subscribed to gnome-power-manager in Ubuntu. https://bugs.launchpad.net/bugs/762670 Title: Laptop brightness on Dell XPS not controllable Status in “gnome-power-manager” package in Ubuntu: Confirmed Bug description: ERROR: Method "GetBrightness" with signature "" on interface "org.freedesktop.UPower.KbdBacklight" doesn't exist The brightness of my laptop's screen is not changed at all when using the Fn-Keys. Ubuntu displays the notification area with the brightness setting displayed, it even shows that the brightness value is changed - but the actual brightness of the screen remains the same at all times! Laptop: Dell XPS 17, Full-HD 3D display, Nvidea graphics. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/762670/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
