+ /*
+ * Don't try to enable a channel if the session has been started at
+ * some point in time before. The tracer does not allow it.
+ */
+ if (session->started) {
+ ret = LTTNG_ERR_TRACE_ALREADY_STARTED;
+ goto error;
+ }
+
+ /*
+ * If the session is a live session, remove the switch timer, the
+ * live timer does the same thing but sends also synchronisation
+ * beacons for inactive streams.
+ */
+ if (session->live_timer > 0) {
+ attr->attr.live_timer_interval = session->live_timer;
+ attr->attr.switch_timer_interval = 0;
+ }
+