2 files changed, 22 insertions, 4 deletions

diff --git a/src/sna/gen6_render.c b/src/sna/gen6_render.c
index 5641b3ca..eb67fc67 100644
--- a/src/sna/gen6_render.c
+++ b/src/sna/gen6_render.c
@@ -2307,7 +2307,8 @@ gen6_render_copy_boxes(struct sna *sna, uint8_t alu,
              __FUNCTION__, src_dx, src_dy, dst_dx, dst_dy, n, alu,
              src_bo == dst_bo));
 
-        if (sna->kgem.mode == KGEM_BLT &&
+        /* XXX benchmark me! */
+        if (sna->kgem.mode != KGEM_RENDER &&
             sna_blt_compare_depth(&src->drawable, &dst->drawable) &&
             sna_blt_copy_boxes(sna, alu,
                                src_bo, src_dx, src_dy,
@@ -2464,7 +2465,8 @@ gen6_render_copy(struct sna *sna, uint8_t alu,
              src->drawable.width, src->drawable.height,
              dst->drawable.width, dst->drawable.height));
 
-        if (sna->kgem.mode == KGEM_BLT &&
+        /* XXX benchmark me! */
+        if (sna->kgem.mode != KGEM_RENDER &&
             sna_blt_compare_depth(&src->drawable, &dst->drawable) &&
             sna_blt_copy(sna, alu,
                          src_bo, dst_bo,
@@ -2577,7 +2579,7 @@ gen6_render_fill_boxes(struct sna *sna,
                 return FALSE;
         }
 
-        if (sna->kgem.mode == KGEM_BLT ||
+        if (sna->kgem.mode != KGEM_RENDER ||
             dst->drawable.width > 8192 ||
             dst->drawable.height > 8192 ||
             !gen6_check_dst_format(format)) {
@@ -2734,7 +2736,7 @@ gen6_render_fill(struct sna *sna, uint8_t alu,
                             op);
 #endif
 
-        if (sna->kgem.mode == KGEM_BLT &&
+        if (sna->kgem.mode != KGEM_RENDER &&
             sna_blt_fill(sna, alu,
                          dst_bo, dst->drawable.bitsPerPixel,
                          color,
diff --git a/src/sna/sna_dri.c b/src/sna/sna_dri.c
index 0a01f8af..f4049f19 100644
--- a/src/sna/sna_dri.c
+++ b/src/sna/sna_dri.c
@@ -461,6 +461,22 @@ sna_dri_copy(struct sna *sna, DrawablePtr draw, RegionPtr region,
                 get_drawable_deltas(draw, dst, &dx, &dy);
         }
 
+        if (sna->kgem.gen >= 60) {
+                /* Sandybridge introduced a separate ring which it uses to
+                 * perform blits. Switching rendering between rings incurs
+                 * a stall as we wait upon the old ring to finish and
+                 * flush its render cache before we can proceed on with
+                 * the operation on the new ring.
+                 *
+                 * As this buffer, we presume, has just been written to by
+                 * the DRI client using the RENDER ring, we want to perform
+                 * our operation on the same ring, and ideally on the same
+                 * ring as we will flip from (which should be the RENDER ring
+                 * as well).
+                 */
+                kgem_set_mode(&sna->kgem, KGEM_RENDER);
+        }
+
         if (region) {
                 boxes = REGION_RECTS(region);
                 n = REGION_NUM_RECTS(region);