I can also confirm that the suggestion posted by "Pierre Chifflier" works. Though myself not being a computer geek I had problems implementing it. Below is the example of how it looks on my xorg.conf file and this works for me.
Section "Screen" Identifier "Screen0" Device "Device0" Monitor "Monitor0" DefaultDepth 24 Option "TwinView" "1" Option "TwinViewXineramaInfoOrder" "DFP-2" Option "metamodes" "DFP-0: 1680x1050 +1920+15, DFP-2: 1920x1080 +0+0" Option "RegistryDwords" "EnableBrightnessControl=1" SubSection "Display" Depth 24 EndSubSection EndSection Note: this is just an example for those who don't know where the following line appears Look above for => Option "RegistryDwords" "EnableBrightnessControl=1" Thanks everyone, Special Thanks to "Pierre Chifflier" Cheers, Hemant -- 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