[Mesa-dev] [RFC 2/5] vulkan: Check whether X server supports DMA fences

[Louis-Francis Ratté-Boulianne]

Signed-off-by: Louis-Francis Ratté-Boulianne <lfrb at collabora.com>
---
 src/vulkan/wsi/wsi_common_x11.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/src/vulkan/wsi/wsi_common_x11.c b/src/vulkan/wsi/wsi_common_x11.c
index ecdaf91434..d132541156 100644
--- a/src/vulkan/wsi/wsi_common_x11.c
+++ b/src/vulkan/wsi/wsi_common_x11.c
@@ -628,6 +628,8 @@ struct x11_image {
 struct x11_swapchain {
    struct wsi_swapchain                        base;
 
+   bool                                         has_dma_fence;
+
    xcb_connection_t *                           conn;
    xcb_window_t                                 window;
    xcb_gc_t                                     gc;
@@ -639,6 +641,7 @@ struct x11_swapchain {
    uint64_t                                     send_sbc;
    uint64_t                                     last_present_msc;
    uint32_t                                     stamp;
+   uint32_t                                     present_capabilities;
 
    bool                                         threaded;
    VkResult                                     status;
@@ -951,6 +954,32 @@ fail:
    return NULL;
 }
 
+static void
+wsi_x11_get_present_capabilities(struct x11_swapchain *chain)
+{
+   xcb_present_query_capabilities_cookie_t present_capabilities_cookie;
+   xcb_present_query_capabilities_reply_t  *present_capabilities_reply;
+
+   if (chain->present_capabilities)
+      return;
+
+   present_capabilities_cookie =
+      xcb_present_query_capabilities(chain->conn, chain->window);
+   present_capabilities_reply =
+        xcb_present_query_capabilities_reply(chain->conn,
+                                                 present_capabilities_cookie,
+                                                 NULL);
+
+   if (present_capabilities_reply) {
+      chain->present_capabilities = present_capabilities_reply->capabilities;
+      chain->has_dma_fence = chain->present_capabilities &
+                             XCB_PRESENT_CAPABILITY_IDLE_FENCE;
+      free(present_capabilities_reply);
+   } else {
+      chain->present_capabilities = 0;
+   }
+}
+
 static VkResult
 x11_image_init(VkDevice device_h, struct x11_swapchain *chain,
                const VkSwapchainCreateInfoKHR *pCreateInfo,
@@ -1011,6 +1040,8 @@ x11_image_init(VkDevice device_h, struct x11_swapchain *chain,
                                           chain->depth, bpp, fd);
    xcb_discard_reply(chain->conn, cookie.sequence);
 
+   wsi_x11_get_present_capabilities(chain);
+
    int fence_fd = xshmfence_alloc_shm();
    if (fence_fd < 0)
       goto fail_pixmap;
-- 
2.13.0