[Mesa-dev] [PATCH] anv/blorp: sample input attachments with resolves on BDW

[Samuel Iglesias Gonsálvez]

On Broadwell we still need to do a resolve between the subpass
that writes and the subpass that reads when there is a
self-dependency because HW could not see fast-clears and works
on the render cache as if there was regular non-fast-clear surface.

Fixes 16 tests on BDW:

dEQP-VK.renderpass.formats.*.input.clear.store.self_dep*

Signed-off-by: Samuel Iglesias Gonsálvez <siglesias at igalia.com>
---
 src/intel/vulkan/anv_blorp.c | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/intel/vulkan/anv_blorp.c b/src/intel/vulkan/anv_blorp.c
index 72a468a744a..daf13d360c4 100644
--- a/src/intel/vulkan/anv_blorp.c
+++ b/src/intel/vulkan/anv_blorp.c
@@ -1457,6 +1457,7 @@ ccs_resolve_attachment(struct anv_cmd_buffer *cmd_buffer,
     * still hot in the cache.
     */
    bool found_draw = false;
+   bool self_dep = false;
    enum anv_subpass_usage usage = 0;
    for (uint32_t s = subpass_idx + 1; s < pass->subpass_count; s++) {
       usage |= pass->attachments[att].subpass_usage[s];
@@ -1466,6 +1467,8 @@ ccs_resolve_attachment(struct anv_cmd_buffer *cmd_buffer,
           * wait to resolve until then.
           */
          found_draw = true;
+         if (pass->attachments[att].subpass_usage[s] & ANV_SUBPASS_USAGE_INPUT)
+            self_dep = true;
          break;
       }
    }
@@ -1509,10 +1512,19 @@ ccs_resolve_attachment(struct anv_cmd_buffer *cmd_buffer,
           */
       }
    } else if (usage & ANV_SUBPASS_USAGE_INPUT) {
-      /* Input attachments are clear-color aware so, at least on Sky Lake, we
+      /* Input attachments are clear-color aware, at least on Sky Lake, so we
        * can frequently sample from them with no resolves at all.
+       *
+       * However on Broadwell we still need to do resolves when there is a
+       * self-dependency because HW could not see fast-clears and works
+       * on the render cache as if there was regular non-fast-clear surface.
+       * To avoid any inconsistency, we force the resolve.
        */
-      if (att_state->aux_usage != att_state->input_aux_usage) {
+      if (cmd_buffer->device->info.gen == 8 && self_dep &&
+          att_state->aux_usage == ISL_AUX_USAGE_CCS_D &&
+          att_state->input_aux_usage == ISL_AUX_USAGE_CCS_D) {
+         resolve_op = BLORP_FAST_CLEAR_OP_RESOLVE_FULL;
+      } else if (att_state->aux_usage != att_state->input_aux_usage) {
          assert(att_state->input_aux_usage == ISL_AUX_USAGE_NONE);
          resolve_op = BLORP_FAST_CLEAR_OP_RESOLVE_FULL;
       } else if (!att_state->clear_color_is_zero_one) {
-- 
2.11.0