r600g: r6xx deadlock workaround (v6)

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=50655
https://bugs.freedesktop.org/show_bug.cgi?id=47116

v2: flush along with workaround.
v3: just need a flush
v4: try WAIT_UNTIL
v5: switch to PS partial flush
v6: rework patch

Note: this is a candidate for the 9.1 branch.

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/gallium/drivers/r600/r600_state_common.c b/src/gallium/drivers/r600/r600_state_common.c
index c4bd758d796..1654233b756 100644
--- a/src/gallium/drivers/r600/r600_state_common.c
+++ b/src/gallium/drivers/r600/r600_state_common.c
@@ -1360,6 +1360,12 @@ static void r600_draw_vbo(struct pipe_context *ctx, const struct pipe_draw_info
                 rctx->vgt_state.atom.dirty = true;
         }
 
+        /* Workaround for hardware deadlock on certain R600 ASICs: write into a CB register. */
+        if (rctx->chip_class == R600) {
+                rctx->flags |= R600_CONTEXT_PS_PARTIAL_FLUSH;
+                rctx->cb_misc_state.atom.dirty = true;
+        }
+
         /* Emit states. */
         r600_need_cs_space(rctx, ib.user_buffer ? 5 : 0, TRUE);
         r600_flush_emit(rctx);