The tiling parameters don't look bogus and they certainly aren't zero. In the
dumped IB there's mt = 1, num_banks = 3, tile_split = 3 in DW 7. Looking at DW
3, there is array_mode = 2, bankw = 0, bankh = 0, mtilea = 0. That might as
well be completely wrong for the given surface, but it's not bogus in the sense
that the values are invalid.

At first I thought bankw/bankh/mtilea being all set to zero was strange, but
this seems to match how libdrm sets up 1D tiled surfaces.

For reference, this is the IB we're talking about:
http://pastebin.com/jFWk9bU5