[PATCH] ui/gtk: skip refresh if new dmabuf is submitted

[Dongwon Kim]

Skip refresh if a new dmabuf (guest scanout frame) is submitted
and ready to be drawn because the scanout will be refreshed with
new frame anyway.

Also, setting scanout mode is better to be done right before
a draw event is scheduled because the mode can be reset anytime
after it is set in dpy_gl_scanout_texture by any asynchronouse
dpy_refresh call, which eventually cancels the drawing of the
guest scanout texture.

Cc: Gerd Hoffmann <kra...@redhat.com>
Cc: Marc-André Lureau <marcandre.lur...@redhat.com>
Cc: Vivek Kasireddy <vivek.kasire...@intel.com>
Signed-off-by: Dongwon Kim <dongwon....@intel.com>
---
 ui/gtk-egl.c     | 6 +++++-
 ui/gtk-gl-area.c | 6 +++++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/ui/gtk-egl.c b/ui/gtk-egl.c
index 19130041bc..62ff6812b6 100644
--- a/ui/gtk-egl.c
+++ b/ui/gtk-egl.c
@@ -143,6 +143,10 @@ void gd_egl_refresh(DisplayChangeListener *dcl)
     gd_update_monitor_refresh_rate(
             vc, vc->window ? vc->window : vc->gfx.drawing_area);
 
+    if (vc->gfx.guest_fb.dmabuf && vc->gfx.guest_fb.dmabuf->draw_submitted) {
+        return;
+    }
+
     if (!vc->gfx.esurface) {
         gd_egl_init(vc);
         if (!vc->gfx.esurface) {
@@ -236,7 +240,6 @@ void gd_egl_scanout_texture(DisplayChangeListener *dcl,
     eglMakeCurrent(qemu_egl_display, vc->gfx.esurface,
                    vc->gfx.esurface, vc->gfx.ectx);
 
-    gtk_egl_set_scanout_mode(vc, true);
     egl_fb_setup_for_tex(&vc->gfx.guest_fb, backing_width, backing_height,
                          backing_id, false);
 }
@@ -344,6 +347,7 @@ void gd_egl_flush(DisplayChangeListener *dcl,
     if (vc->gfx.guest_fb.dmabuf && !vc->gfx.guest_fb.dmabuf->draw_submitted) {
         graphic_hw_gl_block(vc->gfx.dcl.con, true);
         vc->gfx.guest_fb.dmabuf->draw_submitted = true;
+        gtk_egl_set_scanout_mode(vc, true);
         gtk_widget_queue_draw_area(area, x, y, w, h);
         return;
     }
diff --git a/ui/gtk-gl-area.c b/ui/gtk-gl-area.c
index c384a1516b..68eff3435b 100644
--- a/ui/gtk-gl-area.c
+++ b/ui/gtk-gl-area.c
@@ -123,6 +123,10 @@ void gd_gl_area_refresh(DisplayChangeListener *dcl)
 
     gd_update_monitor_refresh_rate(vc, vc->window ? vc->window : 
vc->gfx.drawing_area);
 
+    if (vc->gfx.guest_fb.dmabuf && vc->gfx.guest_fb.dmabuf->draw_submitted) {
+        return;
+    }
+
     if (!vc->gfx.gls) {
         if (!gtk_widget_get_realized(vc->gfx.drawing_area)) {
             return;
@@ -261,7 +265,6 @@ void gd_gl_area_scanout_texture(DisplayChangeListener *dcl,
         return;
     }
 
-    gtk_gl_area_set_scanout_mode(vc, true);
     egl_fb_setup_for_tex(&vc->gfx.guest_fb, backing_width, backing_height,
                          backing_id, false);
 }
@@ -281,6 +284,7 @@ void gd_gl_area_scanout_flush(DisplayChangeListener *dcl,
     if (vc->gfx.guest_fb.dmabuf && !vc->gfx.guest_fb.dmabuf->draw_submitted) {
         graphic_hw_gl_block(vc->gfx.dcl.con, true);
         vc->gfx.guest_fb.dmabuf->draw_submitted = true;
+        gtk_gl_area_set_scanout_mode(vc, true);
     }
     gtk_gl_area_queue_render(GTK_GL_AREA(vc->gfx.drawing_area));
 }
-- 
2.34.1