stops updating the vertical retrace indicator. The text mouse
renderer in syscons is executing from the callout and spins waiting
for the start of next frame. As result, after the X server finishes,
since the VGA cannot be turned on, but syscons does not know about
this, the clock swi spins forever.
Hack around the problem by disabling wait for the retrace if KMS is
activated.
Diagnosed and tested by: Michiel Boland <boland37@xs4all.nl>
Sponsored by: The FreeBSD Foundation
MFC after: 2 weeks
works with new generations of GPUs (IronLake, SandyBridge and
supposedly IvyBridge).
The driver is not connected to the build yet.
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
