[Mesa-dev] [PATCH] i965/blorp: Fix hiz ops on MSAA surfaces

[Chris Forbes]

Two things were broken here:
- The depth/stencil surface dimensions were broken for MSAA.
- Sample count was programmed incorrectly.

Result was the depth resolve didn't work correctly on MSAA surfaces, and
so sampling the surface later produced garbage.

Fixes the new piglit test arb_texture_multisample-sample-depth, and
various artifacts in 'tesseract' with msaa=4 glineardepth=0.

Not observed any piglit regressions on Haswell.

v2: Just set brw_hiz_op_params::dst.num_samples rather than adding a
    helper function (Ken).

Signed-off-by: Chris Forbes <chrisf at ijw.co.nz>
---
 src/mesa/drivers/dri/i965/brw_blorp.cpp  |  1 +
 src/mesa/drivers/dri/i965/gen7_blorp.cpp | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp.cpp b/src/mesa/drivers/dri/i965/brw_blorp.cpp
index 20ce7b7..0ecf330 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp.cpp
@@ -323,6 +323,7 @@ brw_hiz_op_params::brw_hiz_op_params(struct intel_mipmap_tree *mt,
     */
    depth.width = ALIGN(depth.width, 8);
    depth.height = ALIGN(depth.height, 4);
+   dst.num_samples = mt->num_samples;
 
    x1 = depth.width;
    y1 = depth.height;
diff --git a/src/mesa/drivers/dri/i965/gen7_blorp.cpp b/src/mesa/drivers/dri/i965/gen7_blorp.cpp
index 206a6ff..03fc9c8 100644
--- a/src/mesa/drivers/dri/i965/gen7_blorp.cpp
+++ b/src/mesa/drivers/dri/i965/gen7_blorp.cpp
@@ -663,6 +663,17 @@ gen7_blorp_emit_depth_stencil_config(struct brw_context *brw,
        */
       surfwidth = params->depth.width;
       surfheight = params->depth.height;
+
+      if (params->dst.num_samples > 1) {
+         /* If this is an MSAA + HIZ op, we need to program the
+          * aligned logical size of the depth surface.
+          */
+         surfwidth = ALIGN(params->depth.mt->logical_width0, 8);
+         surfheight = ALIGN(params->depth.mt->logical_height0, 4);
+      } else {
+         surfwidth = params->depth.width;
+         surfheight = params->depth.height;
+      }
    } else {
       surfwidth = params->depth.mt->logical_width0;
       surfheight = params->depth.mt->logical_height0;
-- 
2.1.3