+ DBG("%s %s to mt %p level %d layers %d-%d\n",
+ __func__, opname, mt, level, start_layer, start_layer + num_layers - 1);
+
+ /* The following stalls and flushes are only documented to be required for
+ * HiZ clear operations. However, they also seem to be required for the
+ * HiZ resolve operation which is basically the same as a fast clear only a
+ * different value is written into the HiZ surface.
+ */
+ if (op == BLORP_HIZ_OP_DEPTH_CLEAR || op == BLORP_HIZ_OP_HIZ_RESOLVE) {
+ if (brw->gen == 6) {
+ /* From the Sandy Bridge PRM, volume 2 part 1, page 313:
+ *
+ * "If other rendering operations have preceded this clear, a
+ * PIPE_CONTROL with write cache flush enabled and Z-inhibit
+ * disabled must be issued before the rectangle primitive used for
+ * the depth buffer clear operation.
+ */
+ brw_emit_pipe_control_flush(brw,
+ PIPE_CONTROL_RENDER_TARGET_FLUSH |
+ PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+ PIPE_CONTROL_CS_STALL);
+ } else if (brw->gen >= 7) {
+ /*
+ * From the Ivybridge PRM, volume 2, "Depth Buffer Clear":
+ *
+ * If other rendering operations have preceded this clear, a
+ * PIPE_CONTROL with depth cache flush enabled, Depth Stall bit
+ * enabled must be issued before the rectangle primitive used for
+ * the depth buffer clear operation.
+ *
+ * Same applies for Gen8 and Gen9.
+ *
+ * In addition, from the Ivybridge PRM, volume 2, 1.10.4.1
+ * PIPE_CONTROL, Depth Cache Flush Enable:
+ *
+ * This bit must not be set when Depth Stall Enable bit is set in
+ * this packet.
+ *
+ * This is confirmed to hold for real, HSW gets immediate gpu hangs.
+ *
+ * Therefore issue two pipe control flushes, one for cache flush and
+ * another for depth stall.
+ */
+ brw_emit_pipe_control_flush(brw,
+ PIPE_CONTROL_DEPTH_CACHE_FLUSH |
+ PIPE_CONTROL_CS_STALL);
+
+ brw_emit_pipe_control_flush(brw, PIPE_CONTROL_DEPTH_STALL);
+ }
+ }