I could disable ATI discrete graphics in Ubuntu 13.10 with this command:
echo OFF > /sys/kernel/debug/vgaswitcheroo/switch
But in Ubuntu 14.04 it does not work. cat /sys/kernel/debug/vgaswitcheroo/switch
shows the same:
0:IGD:+:DynPwr:0000:01:05.0
1:DIS-Audio: :Pwr:0000:02:00.1
2:DIS: :DynPwr:0000:02:00.0
What should I do in Ubuntu 14.04?