I'm trying to control the brightness of my notebook's screen using NVIDIA X Server but the changes only persist for a few seconds, then turns back to the default settings.
**I've already tried all i've found on the internet about this problem (xorg.conf, grub).
Also have tried changing the brightness from the terminal but it doesn't even recognize the device.
$ sudo setpci -s 00:02.0 F4.B=20
setpci: Warning: No devices selected for "F4.B=20".
This is very frustrating because my battery doesn't last as long as it does on windows.
My notebook is a Toshiba Satellite L750 with Geforce GT550.
$ lspci | grep nV
01:00.0 VGA compatible controller: nVidia Corporation Device 0dec (rev a1)
01:00.1 Audio device: nVidia Corporation GF108 High Definition Audio Controller (rev a1)
