mpv: Delays the fade in after enable returns

sources/mpv/source.go

@@ -124,13 +124,20 @@ func (s *MPVSource) Enable() (err error) {
 		}
 
 		var pfc interface{}
+		pfc, err = conn.Get("core-idle")
+
+		if err == nil && pfc.(bool) {
+			go func() {
 				for err == nil && pfc.(bool) {
 					time.Sleep(250 * time.Millisecond)
 					pfc, err = conn.Get("core-idle")
 				}
-		err = nil
 
 				s.FadeIn(conn, 3, 50)
+			}()
+		} else {
+			s.FadeIn(conn, 3, 50)
+		}
 	}
 
 	return