drm/vc4: Fix races when the CS reads from render targets.

drm/vc4: Fix races when the CS reads from render targets.

commit 7edabee06a5622190d59689a64f5e17d1c343cc3 upstream.

With the introduction of bin/render pipelining, the previous job may
not be completed when we start binning the next one.  If the previous
job wrote our VBO, IB, or CS textures, then the binning stage might
get stale or uninitialized results.

Fixes the major rendering failure in glmark2 -b terrain.

Signed-off-by: Eric Anholt <eric@anholt.net>
Fixes: ca26d28bbaa3 ("drm/vc4: improve throughput by pipelining binning and rendering jobs")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>