i965/gen7: Fix GPU hangs from the HiZ op.

The wm max threads is in the same dword as the dispatch enable.  The
hardware gets super angry if you set max threads to 0, even if you
aren't dispatching threads.

diff --git a/src/mesa/drivers/dri/i965/gen7_hiz.c b/src/mesa/drivers/dri/i965/gen7_hiz.c
index 271e61e..a36f1cb 100644 (file)
--- a/src/mesa/drivers/dri/i965/gen7_hiz.c
+++ b/src/mesa/drivers/dri/i965/gen7_hiz.c
@@ -322,8 +322,9 @@ gen7_hiz_exec(struct intel_context *intel,
       OUT_BATCH(_3DSTATE_PS << 16 | (8 - 2));
       OUT_BATCH(0);
       OUT_BATCH(0);
-      OUT_BATCH((brw->max_wm_threads - 1) << GEN7_PS_MAX_THREADS_SHIFT);
-      OUT_BATCH(GEN7_PS_32_DISPATCH_ENABLE);
+      OUT_BATCH(0);
+      OUT_BATCH(((brw->max_wm_threads - 1) << GEN7_PS_MAX_THREADS_SHIFT) |
+               GEN7_PS_32_DISPATCH_ENABLE);
       OUT_BATCH(0);
       OUT_BATCH(0);
       OUT_BATCH(0);