[Mesa-dev] [PATCH 2/4] i965/gen6+: Fix copying of stencil images in blorp CopyTexSubImage path.

[Paul Berry]

When handling the depth/stencil case of CopyTexSubImage using blorp,
we weren't paying attention to intel_mipmap_tree::stencil_mt field; as
a result we were sometimes attempting to read and/or write stencil
data using the depth miptree, resulting in image corruption.

Fixes some failures with piglit tests "copyteximage
{1D,2D,CUBE,RECT,2D_ARRAY}".
---
 src/mesa/drivers/dri/i965/brw_blorp_blit.cpp | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
index 0a9aca8..3417a99 100644
--- a/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_blorp_blit.cpp
@@ -380,16 +380,20 @@ brw_blorp_copytexsubimage(struct intel_context *intel,
                            dstX0, dstY0, dstX1, dstY1,
                            false, mirror_y);
 
-   /* If we're copying to a packed depth stencil texture and the source
-    * framebuffer has separate stencil, we need to also copy the stencil data
-    * over.
+   /* Blorp only ever copies one miptree at a time.  Since Gen6+ uses separate
+    * stencil buffers, this means that the above copy just copied depth.  If
+    * we're copying to a depth/stencil texture and the source framebuffer has
+    * stencil, we need to also copy the stencil data over.
     */
    src_rb = ctx->ReadBuffer->Attachment[BUFFER_STENCIL].Renderbuffer;
    if (_mesa_get_format_bits(dst_image->TexFormat, GL_STENCIL_BITS) > 0 &&
        src_rb != NULL) {
       src_irb = intel_renderbuffer(src_rb);
-      if (src_irb->mt != src_mt)
-
+      src_mt = src_irb->mt;
+      if (src_mt->stencil_mt)
+         src_mt = src_mt->stencil_mt;
+      if (dst_mt->stencil_mt)
+         dst_mt = dst_mt->stencil_mt;
       brw_blorp_blit_miptrees(intel,
                               src_irb->mt, src_irb->mt_level, src_irb->mt_layer,
                               dst_mt, dst_image->Level, dst_image->Face,
-- 
1.8.3