diff --git a/sys/dev/sound/dummy.c b/sys/dev/sound/dummy.c
--- a/sys/dev/sound/dummy.c
+++ b/sys/dev/sound/dummy.c
@@ -65,6 +65,7 @@
 	struct dummy_chan chans[DUMMY_NCHAN];
 	struct callout callout;
 	struct mtx *lock;
+	bool stopped;
 };
 
 static bool
@@ -92,6 +93,9 @@
 	struct dummy_chan *ch;
 	int i = 0;
 
+	if (sc->stopped)
+		return;
+
 	/* Do not reschedule if no channel is running. */
 	if (!dummy_active(sc))
 		return;
@@ -108,7 +112,8 @@
 		chn_intr(ch->chan);
 		snd_mtxlock(sc->lock);
 	}
-	callout_schedule(&sc->callout, 1);
+	if (!sc->stopped)
+		callout_schedule(&sc->callout, 1);
 }
 
 static int
@@ -195,6 +200,11 @@
 
 	snd_mtxlock(sc->lock);
 
+	if (sc->stopped) {
+		snd_mtxunlock(sc->lock);
+		return (0);
+	}
+
 	switch (go) {
 	case PCMTRIG_START:
 		ch->ptr = 0;
@@ -345,8 +355,11 @@
 	struct dummy_softc *sc = device_get_softc(dev);
 	int err;
 
-	err = pcm_unregister(dev);
+	snd_mtxlock(sc->lock);
+	sc->stopped = true;
+	snd_mtxunlock(sc->lock);
 	callout_drain(&sc->callout);
+	err = pcm_unregister(dev);
 	snd_mtxfree(sc->lock);
 
 	return (err);