add comment for DisplayState->idle

Signed-off-by: NGerd Hoffmann <kraxel@redhat.com>
Signed-off-by: NAurelien Jarno <aurelien@aurel32.net>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5071 c046a42c-6fe2-441c-8c8c-71466251a162

console.h

@@ -83,7 +83,7 @@ struct DisplayState {
     void *opaque;
     struct QEMUTimer *gui_timer;
     uint64_t gui_timer_interval;
-    int idle;
+    int idle; /* there is nothing to update (window invisible), set by vnc/sdl */
 
     void (*dpy_update)(struct DisplayState *s, int x, int y, int w, int h);
     void (*dpy_resize)(struct DisplayState *s, int w, int h);