I followed this how-to to get vgaswitcheroo working on my macbook 8,2: How to switch between Gfx cards on Macbook Pro 15" 8.2
I can boot directly from refind (bypassing grub); and I get X working with the radeon and keyboard OK. But I am unable to switch: I get a blank screen when I use vgaswitcheroo to switch to IGD. I can blindly switch back to DIS, and it works which means the laptop is not frozen. Any idea what causes that? I use kernel 3.8.0-19 generic from ubuntu 13.04. I also tried kernel vmlinuz-3.8.0-030800rc2-generic from the how-to bu no change.
By the way, I had to modprobe i915 to see the file vgaswitcheroo/switch. Is there anything else I have to do to get it work?