[Mesa-dev] [PATCH 4/4] i965/blorp: Make post draw flush more explicit

[Topi Pohjolainen]

Blits do not need any special treatment as the target buffer
object is added to render cache just as one does for normal draw.
Color clears and resolves in turn require explicit "end of pipe
synchronization". It is not clear what this means exactly but the
assumption is that render cache flush with command stream stall
should be sufficient.

Signed-off-by: Topi Pohjolainen <topi.pohjolainen at intel.com>
---
 src/mesa/drivers/dri/i965/brw_blorp.c       | 22 ++++++++++++++++++++++
 src/mesa/drivers/dri/i965/genX_blorp_exec.c |  5 -----
 2 files changed, 22 insertions(+), 5 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp.c b/src/mesa/drivers/dri/i965/brw_blorp.c
index 8d58616..845abe3 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp.c
+++ b/src/mesa/drivers/dri/i965/brw_blorp.c
@@ -908,6 +908,17 @@ do_single_blorp_clear(struct brw_context *brw, struct gl_framebuffer *fb,
       blorp_batch_finish(&batch);
    }
 
+   /*
+    * IvyBrigde PRM Vol 2, Part 1, "11.7 MCS Buffer for Render Target(s)":
+    *
+    *  Any transition from any value in {Clear, Render, Resolve} to a
+    *  different value in {Clear, Render, Resolve} requires end of pipe
+    *  synchronization.
+    */
+   brw_emit_pipe_control_flush(brw,
+                               PIPE_CONTROL_RENDER_TARGET_FLUSH |
+                               PIPE_CONTROL_CS_STALL);
+
    return true;
 }
 
@@ -975,6 +986,17 @@ brw_blorp_resolve_color(struct brw_context *brw, struct intel_mipmap_tree *mt,
                      brw_blorp_to_isl_format(brw, format, true),
                      resolve_op);
    blorp_batch_finish(&batch);
+
+   /*
+    * IvyBrigde PRM Vol 2, Part 1, "11.7 MCS Buffer for Render Target(s)":
+    *
+    *  Any transition from any value in {Clear, Render, Resolve} to a
+    *  different value in {Clear, Render, Resolve} requires end of pipe
+    *  synchronization.
+    */
+   brw_emit_pipe_control_flush(brw,
+                               PIPE_CONTROL_RENDER_TARGET_FLUSH |
+                               PIPE_CONTROL_CS_STALL);
 }
 
 static void
diff --git a/src/mesa/drivers/dri/i965/genX_blorp_exec.c b/src/mesa/drivers/dri/i965/genX_blorp_exec.c
index c0cbde5..2c53444 100644
--- a/src/mesa/drivers/dri/i965/genX_blorp_exec.c
+++ b/src/mesa/drivers/dri/i965/genX_blorp_exec.c
@@ -260,9 +260,4 @@ retry:
    brw->ib.type = -1;
 
    brw_render_cache_set_add_bo(brw, params->dst.addr.buffer);
-
-   /* Flush the sampler cache so any texturing from the destination is
-    * coherent.
-    */
-   brw_emit_mi_flush(brw);
 }
-- 
2.5.5