Index: /usr/src/sys/dev/sound/clone.h
===================================================================
--- /usr/src/sys/dev/sound/clone.h
+++ /usr/src/sys/dev/sound/clone.h
@@ -116,6 +116,7 @@
 uint32_t snd_clone_getdevflags(struct cdev *);
 uint32_t snd_clone_setdevflags(struct cdev *, uint32_t);
 int snd_clone_gc(struct snd_clone *);
+void snd_clone_force_destroy_all(struct snd_clone *);
 void snd_clone_destroy(struct snd_clone *);
 int snd_clone_acquire(struct cdev *);
 int snd_clone_release(struct cdev *);
Index: /usr/src/sys/dev/sound/clone.c
===================================================================
--- /usr/src/sys/dev/sound/clone.c
+++ /usr/src/sys/dev/sound/clone.c
@@ -41,6 +41,7 @@
 #include <dev/sound/pcm/sound.h>
 #endif
 
+#include <dev/sound/pcm/dsp.h>
 #include <dev/sound/clone.h>
 
 /*
@@ -448,7 +449,27 @@
 	return (pruned);
 }
 
+/*
+ * Requare:
+ * PCM_GIANT_ENTER(d);
+ * PCM_LOCK(d);
+ * PCM_WAIT(d);
+ * PCM_ACQUIRE(d);
+ */
 void
+snd_clone_force_destroy_all(struct snd_clone *c)
+{
+	struct snd_clone_entry *ce, *tce;
+
+	SND_CLONE_ASSERT(c != NULL, ("NULL snd_clone"));
+
+	TAILQ_FOREACH_REVERSE_SAFE(ce, &c->head, link_head, link, tce) {
+		dsp_close_locked(ce->devt, 0, 0, NULL);
+		ce->devt = NULL;
+	}
+}
+
+void
 snd_clone_destroy(struct snd_clone *c)
 {
 	struct snd_clone_entry *ce, *tmp;
Index: /usr/src/sys/dev/sound/pcm/dsp.h
===================================================================
--- /usr/src/sys/dev/sound/pcm/dsp.h
+++ /usr/src/sys/dev/sound/pcm/dsp.h
@@ -31,9 +31,12 @@
 #ifndef _PCMDSP_H_
 #define _PCMDSP_H_
 
+#include <sys/soundcard.h>
+
 extern struct cdevsw dsp_cdevsw;
 
 struct dsp_cdevinfo;
+struct snddev_info;
 
 char *dsp_unit2name(char *, size_t, int);
 int dsp_oss_audioinfo(struct cdev *, oss_audioinfo *);
@@ -41,4 +44,6 @@
 void dsp_cdevinfo_init(struct snddev_info *);
 void dsp_cdevinfo_flush(struct snddev_info *);
 
+int dsp_close_locked(struct cdev *, int, int, struct thread *);
+
 #endif /* !_PCMDSP_H_ */
Index: /usr/src/sys/dev/sound/pcm/dsp.c
===================================================================
--- /usr/src/sys/dev/sound/pcm/dsp.c
+++ /usr/src/sys/dev/sound/pcm/dsp.c
@@ -696,23 +696,14 @@
 	return (0);
 }
 
-static int
-dsp_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
+int
+dsp_close_locked(struct cdev *i_dev, int flags, int mode, struct thread *td)
 {
+	int sg_ids, rdref, wdref;
+	struct snddev_info *d;
 	struct pcm_channel *rdch, *wrch, *volch;
-	struct snddev_info *d;
-	int sg_ids, rdref, wdref;
 
 	d = dsp_get_info(i_dev);
-	if (!DSP_REGISTERED(d, i_dev))
-		return (EBADF);
-
-	PCM_GIANT_ENTER(d);
-
-	PCM_LOCK(d);
-	PCM_WAIT(d);
-	PCM_ACQUIRE(d);
-
 	rdch = PCM_RDCH(i_dev);
 	wrch = PCM_WRCH(i_dev);
 	volch = PCM_VOLCH(i_dev);
@@ -806,12 +797,33 @@
 	(void)snd_clone_unref(i_dev);
 	PCM_LOCK(d);
 
+	return (0);
+}
+
+static int
+dsp_close(struct cdev *i_dev, int flags, int mode, struct thread *td)
+{
+	int ret;
+	struct snddev_info *d;
+
+	d = dsp_get_info(i_dev);
+	if (!DSP_REGISTERED(d, i_dev))
+		return (EBADF);
+
+	PCM_GIANT_ENTER(d);
+
+	PCM_LOCK(d);
+	PCM_WAIT(d);
+	PCM_ACQUIRE(d);
+
+	ret = dsp_close_locked(i_dev, flags, mode, td);
+
 	PCM_RELEASE(d);
 	PCM_UNLOCK(d);
 
 	PCM_GIANT_LEAVE(d);
 
-	return (0);
+	return (ret);
 }
 
 static __inline int
Index: /usr/src/sys/dev/sound/pcm/mixer.c
===================================================================
--- /usr/src/sys/dev/sound/pcm/mixer.c
+++ /usr/src/sys/dev/sound/pcm/mixer.c
@@ -771,25 +771,14 @@
 
 	d = device_get_softc(dev);
 	pdev = mixer_get_devt(dev);
-	if (d == NULL || pdev == NULL || pdev->si_drv1 == NULL)
+	if (d == NULL || pdev == NULL || (m = pdev->si_drv1) == NULL)
 		return EBADF;
 
-	m = pdev->si_drv1;
 	KASSERT(m != NULL, ("NULL snd_mixer"));
 	KASSERT(m->type == MIXER_TYPE_PRIMARY,
 	    ("%s(): illegal mixer type=%d", __func__, m->type));
 
-	snd_mtxlock(m->lock);
-
-	if (m->busy) {
-		snd_mtxunlock(m->lock);
-		return EBUSY;
-	}
-
-	/* destroy dev can sleep --hps */
-
-	snd_mtxunlock(m->lock);
-
+	d->mixer_dev = NULL;
 	pdev->si_drv1 = NULL;
 	destroy_dev(pdev);
 
@@ -809,7 +798,6 @@
 	snd_mtxfree(m->lock);
 	kobj_delete((kobj_t)m, M_MIXER);
 
-	d->mixer_dev = NULL;
 
 	--mixer_count;
 
Index: /usr/src/sys/dev/sound/pcm/sound.c
===================================================================
--- /usr/src/sys/dev/sound/pcm/sound.c
+++ /usr/src/sys/dev/sound/pcm/sound.c
@@ -1142,10 +1142,7 @@
 pcm_unregister(device_t dev)
 {
 	struct snddev_info *d;
-	struct pcm_channel *ch;
-	struct thread *td;
 
-	td = curthread;
 	d = device_get_softc(dev);
 
 	if (!PCM_ALIVE(d)) {
@@ -1163,43 +1160,18 @@
 	}
 
 	PCM_ACQUIRE(d);
-	PCM_UNLOCK(d);
 
-	CHN_FOREACH(ch, d, channels.pcm) {
-		CHN_LOCK(ch);
-		if (ch->refcount > 0) {
-			device_printf(dev,
-			    "unregister: channel %s busy (pid %d)\n",
-			    ch->name, ch->pid);
-			CHN_UNLOCK(ch);
-			PCM_RELEASE_QUICK(d);
-			return (EBUSY);
-		}
-		CHN_UNLOCK(ch);
-	}
-
 	if (d->clones != NULL) {
-		if (snd_clone_busy(d->clones) != 0) {
-			device_printf(dev, "unregister: clone busy\n");
-			PCM_RELEASE_QUICK(d);
-			return (EBUSY);
-		} else {
-			PCM_LOCK(d);
-			(void)snd_clone_disable(d->clones);
-			PCM_UNLOCK(d);
-		}
+		(void)snd_clone_disable(d->clones);
+		PCM_GIANT_ENTER(d);
+		snd_clone_force_destroy_all(d->clones);
+		PCM_GIANT_LEAVE(d);
 	}
 
-	if (mixer_uninit(dev) == EBUSY) {
-		device_printf(dev, "unregister: mixer busy\n");
-		PCM_LOCK(d);
-		if (d->clones != NULL)
-			(void)snd_clone_enable(d->clones);
-		PCM_RELEASE(d);
-		PCM_UNLOCK(d);
-		return (EBUSY);
-	}
+	PCM_UNLOCK(d);
 
+	mixer_uninit(dev);
+
 	/* remove /dev/sndstat entry first */
 	sndstat_unregister(dev);
 	
Index: /usr/src/sys/dev/sound/usb/uaudio.c
===================================================================
--- /usr/src/sys/dev/sound/usb/uaudio.c
+++ /usr/src/sys/dev/sound/usb/uaudio.c
@@ -1204,7 +1204,8 @@
 		error = pcm_unregister(dev);
 	} else {
 		if (sc->sc_mixer_init) {
-			error = mixer_uninit(dev);
+			error = 0;
+			mixer_uninit(dev);
 		}
 	}