Dale's Random Ramblings ;-)

$ lspci
….
00:02.0 VGA compatible controller: Intel Corporation Mobile 4 Series Chipset Integrated Graphics Controller (rev 07)
….

This is just a workaround at the moment so the Backlight can be manually be adjusted with xbacklight

Installing xbacklight

# apt-get install xbacklight

Now we need to set BACKLIGHT_CONTROL

$ xrandr –output LVDS –set BACKLIGHT_CONTROL native

Now we can adjust backlight like this for example

$ xbacklight -set 100