In a HP sleekbook 15 laptop I managed to install NVidia driver and also quick switch graphics is working. When NVidia card is active I can adjust the brightness using keyboard but when intel card is active the adjust is not possible. I have to mention that I have followed next advice "Edit /usr/share/X11/xorg.conf.d/20-intel.conf as root. Enter the following text:
Section "Device" Identifier "card0" Driver "intel" Option "Backlight" "intel_backlight" BusID "PCI:0:2:0" EndSection "
but still doesnt work for intel graphic card.
Someone can help? Thank you!