video drivers are locked up; panic during shutdown

So while the unstable, reverse-engineered ATI drivers were locked up (which is usual, it happens ~5 times a day on average), I pressed the ATX power button to initiate a clean shutdown (statistically, this usually succeeds). During the shutdown procedure, a panic occurred. (As a result, the filesystem wasn't cleanly unmounted.)

I was doing a ``git pull --rebase'' (which turned out to have succeeded) when the driver lockup occurred.

The crashinfo output is attached. Note: the kernel used during the panic has no debugging symbols; a version compiled with debugging symbols was used for crashinfo.