From: Brian Ho <brian@brkho.com>
Date: Sun, 26 Jan 2020 23:12:11 +0000 (-0800)
Subject: anv: Properly fetch partial results in vkGetQueryPoolResults
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=af92ce50a7e56d313f5623136d3f09e7c76475fa;p=mesa.git

anv: Properly fetch partial results in vkGetQueryPoolResults

Currently, fetching the partial results (VK_QUERY_RESULT_PARTIAL_BIT)
of an unavailable occlusion query via vkGetQueryPoolResults can
return invalid values. anv returns slot.end - slot.begin, but in the
case of unavailable queries, slot.end is still at the initial value
of 0. If slot.begin is non-zero, the occlusion count underflows to
a value that is likely outside the acceptable range of the partial
result.

This commit fixes vkGetQueryPoolResults by always returning 0 if the
query is unavailable and the VK_QUERY_RESULT_PARTIAL_BIT is set.

Cc: <mesa-stable@lists.freedesktop.org>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3586>
---

diff --git a/src/intel/vulkan/genX_query.c b/src/intel/vulkan/genX_query.c
index 04c58871be9..c549b13960b 100644
--- a/src/intel/vulkan/genX_query.c
+++ b/src/intel/vulkan/genX_query.c
@@ -308,8 +308,17 @@ VkResult genX(GetQueryPoolResults)(
       switch (pool->type) {
       case VK_QUERY_TYPE_OCCLUSION: {
          uint64_t *slot = query_slot(pool, firstQuery + i);
-         if (write_results)
-            cpu_write_query_result(pData, flags, idx, slot[2] - slot[1]);
+         if (write_results) {
+            /* From the Vulkan 1.2.132 spec:
+             *
+             *    "If VK_QUERY_RESULT_PARTIAL_BIT is set,
+             *    VK_QUERY_RESULT_WAIT_BIT is not set, and the query’s status
+             *    is unavailable, an intermediate result value between zero and
+             *    the final result value is written to pData for that query."
+             */
+            uint64_t result = available ? slot[2] - slot[1] : 0;
+            cpu_write_query_result(pData, flags, idx, result);
+         }
          idx++;
          break;
       }