[SOLVED] [Linux + Dell L702x + fn+key] Problem with backlight Up + Down

After install Gentoo at my new notebook DELL L702x I had problems with backlight functional keys. I really can't to dim and brighten my LCD. I thought that it is hardware fault but it was mistake and big wrong, because on windows it works good. I asked myself WHY? I hadn't time to solve it at that time. Today I found answer! The answer is in the xorg.conf Answer URL: https://bugs.launchpad.net/ubuntu/+source/gnome-power-manager/+bug/762670/comments/15 In the /usr/share/X11/xorg.conf.d/20-nvidia.conf I or you should add in the "Device" section that line: Option "RegistryDwords" "EnableBrightnessControl=1" And Brightness Up / Down functional keys will be works! Gentoo/Linux is amasing operating system! Only One Line at only one place and human is happy!!! Gentoo and Linux Fun again !!!