(In reply to comment #9)
> The hangs are gone if I apply my workaround which fixes the compile failures.

If you mean -

st/mesa, gallium: add a workaround for Unigine Heaven 4.0 and Valley 1.0

I hadn't tried, I assumed they would go in, and now it looks like the stuff in
common has moved up a level.

Checking patch src/gallium/state_trackers/dri/common/dri_context.c...
error: src/gallium/state_trackers/dri/common/dri_context.c: No such file or
directory