Interesting. Dies in PMU preinit somewhere, which in turn calls nkvm_pmu_reset.
I don't see an obvious reason for that to die except ... if PTIMER is somehow
off?

The only difference is from 1e2115d8c0c0da62405400316f5499d909e479bc which
makes it so that nvkm_falcon_v1_new is now being called, although I can't
imagine what would go wrong there.

This will require someone who knows what they're doing to figure out ... i.e.
not me. Hopefully Ben can take a look.