ui/gtk: skip any extra draw of same guest scanout blob res

Any extra draw call for the same blob resource representing guest scanout
before the previous drawing is not finished can break synchronous draw
sequence. To prevent this, drawing is now done only once for each draw
submission (when draw_submitted == true).

v2:
 - removed mutex
 - updated commit msg

Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Vivek Kasireddy <vivek.kasireddy@intel.com>
Signed-off-by: Dongwon Kim <dongwon.kim@intel.com>
Message-Id: <20210924225105.24930-1-dongwon.kim@intel.com>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 27 insertions, 13 deletions

diff --git a/ui/gtk-egl.c b/ui/gtk-egl.c
index 72ce5e1f8f..e912b20075 100644
--- a/ui/gtk-egl.c
+++ b/ui/gtk-egl.c
@@ -63,6 +63,9 @@ void gd_egl_init(VirtualConsole *vc)
 void gd_egl_draw(VirtualConsole *vc)
 {
     GdkWindow *window;
+#ifdef CONFIG_GBM
+    QemuDmaBuf *dmabuf = vc->gfx.guest_fb.dmabuf;
+#endif
     int ww, wh;
 
     if (!vc->gfx.gls) {
@@ -74,10 +77,31 @@ void gd_egl_draw(VirtualConsole *vc)
     wh = gdk_window_get_height(window);
 
     if (vc->gfx.scanout_mode) {
+#ifdef CONFIG_GBM
+        if (dmabuf) {
+            if (!dmabuf->draw_submitted) {
+                return;
+            } else {
+                dmabuf->draw_submitted = false;
+            }
+        }
+#endif
         gd_egl_scanout_flush(&vc->gfx.dcl, 0, 0, vc->gfx.w, vc->gfx.h);
 
         vc->gfx.scale_x = (double)ww / vc->gfx.w;
         vc->gfx.scale_y = (double)wh / vc->gfx.h;
+
+        glFlush();
+#ifdef CONFIG_GBM
+        if (dmabuf) {
+            egl_dmabuf_create_fence(dmabuf);
+            if (dmabuf->fence_fd > 0) {
+                qemu_set_fd_handler(dmabuf->fence_fd, gd_hw_gl_flushed, NULL, vc);
+                return;
+            }
+            graphic_hw_gl_block(vc->gfx.dcl.con, false);
+        }
+#endif
     } else {
         if (!vc->gfx.ds) {
             return;
@@ -92,21 +116,10 @@ void gd_egl_draw(VirtualConsole *vc)
 
         vc->gfx.scale_x = (double)ww / surface_width(vc->gfx.ds);
         vc->gfx.scale_y = (double)wh / surface_height(vc->gfx.ds);
-    }
-
-    glFlush();
-#ifdef CONFIG_GBM
-    if (vc->gfx.guest_fb.dmabuf) {
-        QemuDmaBuf *dmabuf = vc->gfx.guest_fb.dmabuf;
 
-        egl_dmabuf_create_fence(dmabuf);
-        if (dmabuf->fence_fd > 0) {
-            qemu_set_fd_handler(dmabuf->fence_fd, gd_hw_gl_flushed, NULL, vc);
-            return;
-        }
-        graphic_hw_gl_block(vc->gfx.dcl.con, false);
+        glFlush();
     }
-#endif
+
     graphic_hw_gl_flushed(vc->gfx.dcl.con);
 }
 
@@ -317,6 +330,7 @@ void gd_egl_flush(DisplayChangeListener *dcl,
 
     if (vc->gfx.guest_fb.dmabuf) {
         graphic_hw_gl_block(vc->gfx.dcl.con, true);
+        vc->gfx.guest_fb.dmabuf->draw_submitted = true;
         gtk_widget_queue_draw_area(area, x, y, w, h);
         return;
     }