Comment # 3 on bug 62246 from Felix von Leitner

The patch is on both kernels I tried, 3.9.0-rc1 and the git kernel.

I agree it sounds like vgaswitcheroo does not actually switch.
Are there any knobs for vgaswitcheroo that I could try?

For switching, I write "ON\nDIS\nOFF" to
/sys/kernel/debug/vgaswitcheroo/switch,
using three separate writes.

That used to work fine.