(In reply to comment #3)
> Anyway, in the command stream dump you provided before, it looked like the
> tiling parameters were totally bogus, mostly all 0. I suspect this needs
> more investigation.

Yeah, that's what I noticed immediately as well. Maybe attach a gdb to X, set a
breakpoint to si_dma_copy_tile and check what those parameters usually look
like.

If they aren't usually all zero (which is likely) we should figure out why they
are zero in this special case.