[Bug 30052] Fails to start X with intel+Ati video, whith modeset=1

https://bugzilla.kernel.org/show_bug.cgi?id=30052

--- Comment #18 from Seth Forshee seth.forshee@canonical.com 2011-08-31 14:16:18 --- I just completed a bisection with some of the reporters to identify what fixed this, and it came down to this commit:

commit 3448a19da479b6bd1e28e2a2be9fa16c6a6feb39 Author: Dave Airlie airlied@redhat.com Date: Tue Jun 1 15:32:24 2010 +1000

vgaarb: use bridges to control VGA routing where possible.

I can't see why this would have any impact on whether or not the GPU is powered on when nouveau probes it. Is there any explanation for why this appears to fix the issue, or is it likely that it's just changing the timing enough to somehow mask it?