From 5d0465a2533d48b200d6ab50a80277f4a1016770 Mon Sep 17 00:00:00 2001
From: Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com>
Date: Wed, 11 Jun 2025 11:13:23 +0200
Subject: [PATCH] panvk: Skip barrier QFOT if src_qfi equals dst_qfi

Do not perform a queue family ownership transfer during memory barriers
if srcQueueFamilyIndex equals dstQueueFamilyIndex, as the Vulkan spec
mandates that this should only happen if the two values are unequal.

Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Reviewed-by: Chia-I Wu <olvaffe@gmail.com>
Reviewed-by: Yiwei Zhang <zzyiwei@chromium.org>
Fixes: 715d6e740a3 ("panvk: improve VK_QUEUE_FAMILY_EXTERNAL support")
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35458>
---
 src/panfrost/vulkan/csf/panvk_vX_cmd_buffer.c | 61 ++++++++++---------
 1 file changed, 32 insertions(+), 29 deletions(-)

diff --git a/src/panfrost/vulkan/csf/panvk_vX_cmd_buffer.c b/src/panfrost/vulkan/csf/panvk_vX_cmd_buffer.c
index 6c8ac684a0b..d94dd1905f5 100644
--- a/src/panfrost/vulkan/csf/panvk_vX_cmd_buffer.c
+++ b/src/panfrost/vulkan/csf/panvk_vX_cmd_buffer.c
@@ -445,36 +445,39 @@ normalize_dependency(VkPipelineStageFlags2 *src_stages,
                      VkAccessFlags2 *src_access, VkAccessFlags2 *dst_access,
                      uint32_t src_qfi, uint32_t dst_qfi)
 {
-   /* queue family acquire operation */
-   switch (src_qfi) {
-   case VK_QUEUE_FAMILY_EXTERNAL:
-      /* no execution dependency and no availability operation */
-      *src_stages = VK_PIPELINE_STAGE_2_NONE;
-      *src_access = VK_ACCESS_2_NONE;
-      break;
-   case VK_QUEUE_FAMILY_FOREIGN_EXT:
-      /* treat the foreign queue as the host */
-      *src_stages = VK_PIPELINE_STAGE_2_HOST_BIT;
-      *src_access = VK_ACCESS_2_HOST_WRITE_BIT;
-      break;
-   default:
-      break;
-   }
+   /* Perform queue family ownership transfer if src and dst are unequal. */
+   if (src_qfi != dst_qfi) {
+      /* queue family acquire operation */
+      switch (src_qfi) {
+      case VK_QUEUE_FAMILY_EXTERNAL:
+         /* no execution dependency and no availability operation */
+         *src_stages = VK_PIPELINE_STAGE_2_NONE;
+         *src_access = VK_ACCESS_2_NONE;
+         break;
+      case VK_QUEUE_FAMILY_FOREIGN_EXT:
+         /* treat the foreign queue as the host */
+         *src_stages = VK_PIPELINE_STAGE_2_HOST_BIT;
+         *src_access = VK_ACCESS_2_HOST_WRITE_BIT;
+         break;
+      default:
+         break;
+      }
 
-   /* queue family release operation */
-   switch (dst_qfi) {
-   case VK_QUEUE_FAMILY_EXTERNAL:
-      /* no execution dependency and no visibility operation */
-      *dst_stages = VK_PIPELINE_STAGE_2_NONE;
-      *dst_access = VK_ACCESS_2_NONE;
-      break;
-   case VK_QUEUE_FAMILY_FOREIGN_EXT:
-      /* treat the foreign queue as the host */
-      *dst_stages = VK_PIPELINE_STAGE_2_HOST_BIT;
-      *dst_access = VK_ACCESS_2_HOST_WRITE_BIT;
-      break;
-   default:
-      break;
+      /* queue family release operation */
+      switch (dst_qfi) {
+      case VK_QUEUE_FAMILY_EXTERNAL:
+         /* no execution dependency and no visibility operation */
+         *dst_stages = VK_PIPELINE_STAGE_2_NONE;
+         *dst_access = VK_ACCESS_2_NONE;
+         break;
+      case VK_QUEUE_FAMILY_FOREIGN_EXT:
+         /* treat the foreign queue as the host */
+         *dst_stages = VK_PIPELINE_STAGE_2_HOST_BIT;
+         *dst_access = VK_ACCESS_2_HOST_WRITE_BIT;
+         break;
+      default:
+         break;
+      }
    }
 
    *src_stages = vk_expand_src_stage_flags2(*src_stages);