--- sys/dev/sound/pcm/sound.h.orig	Thu Sep 15 11:25:29 2005
+++ sys/dev/sound/pcm/sound.h	Thu Sep 15 11:31:19 2005
@@ -238,11 +238,12 @@
 int sysctl_hw_snd_vchans(SYSCTL_HANDLER_ARGS);
 
 typedef int (*sndstat_handler)(struct sbuf *s, device_t dev, int verbose);
+int sndstat_acquire(void);
+int sndstat_release(void);
 int sndstat_register(device_t dev, char *str, sndstat_handler handler);
 int sndstat_registerfile(char *str);
 int sndstat_unregister(device_t dev);
 int sndstat_unregisterfile(char *str);
-int sndstat_busy(void);
 
 #define SND_DECLARE_FILE(version) \
 	_SND_DECLARE_FILE(__LINE__, version)
--- sys/dev/sound/pcm/sndstat.c.orig	Thu Sep 15 11:25:01 2005
+++ sys/dev/sound/pcm/sndstat.c	Thu Sep 15 11:31:07 2005
@@ -195,6 +195,42 @@
 }
 
 int
+sndstat_acquire(void)
+{
+	intrmask_t s;
+
+	s = spltty();
+	sx_xlock(&sndstat_lock);
+	if (sndstat_isopen) {
+		sx_unlock(&sndstat_lock);
+		splx(s);
+		return EBUSY;
+	}
+	sndstat_isopen = 1;
+	sx_unlock(&sndstat_lock);
+	splx(s);
+	return 0;
+}
+
+int
+sndstat_release(void)
+{
+	intrmask_t s;
+
+	s = spltty();
+	sx_xlock(&sndstat_lock);
+	if (!sndstat_isopen) {
+		sx_unlock(&sndstat_lock);
+		splx(s);
+		return EBADF;
+	}
+	sndstat_isopen = 0;
+	sx_unlock(&sndstat_lock);
+	splx(s);
+	return 0;
+}
+
+int
 sndstat_register(device_t dev, char *str, sndstat_handler handler)
 {
 	intrmask_t s;
@@ -371,12 +407,6 @@
 	sx_xunlock(&sndstat_lock);
 	sx_destroy(&sndstat_lock);
 	return 0;
-}
-
-int
-sndstat_busy(void)
-{
-	return (sndstat_isopen);
 }
 
 static void
--- sys/dev/sound/pcm/sound.c.orig	Thu Sep 15 11:25:05 2005
+++ sys/dev/sound/pcm/sound.c	Thu Sep 15 11:31:07 2005
@@ -758,24 +758,25 @@
     	struct snddev_channel *sce;
 	struct pcm_channel *ch;
 
+	if (sndstat_acquire() != 0) {
+		device_printf(dev, "unregister: sndstat busy\n");
+		return EBUSY;
+	}
+	
 	snd_mtxlock(d->lock);
 	if (d->inprog) {
 		device_printf(dev, "unregister: operation in progress\n");
 		snd_mtxunlock(d->lock);
+		sndstat_release();
 		return EBUSY;
 	}
-	if (sndstat_busy() != 0) {
-		device_printf(dev, "unregister: sndstat busy\n");
-		snd_mtxunlock(d->lock);
-		return EBUSY;
-	}
-
 
 	SLIST_FOREACH(sce, &d->channels, link) {
 		ch = sce->channel;
 		if (ch->refcount > 0) {
 			device_printf(dev, "unregister: channel %s busy (pid %d)\n", ch->name, ch->pid);
 			snd_mtxunlock(d->lock);
+			sndstat_release();
 			return EBUSY;
 		}
 	}
@@ -783,6 +784,7 @@
 	if (mixer_uninit(dev)) {
 		device_printf(dev, "unregister: mixer busy\n");
 		snd_mtxunlock(d->lock);
+		sndstat_release();
 		return EBUSY;
 	}
 
@@ -807,9 +809,10 @@
 	chn_kill(d->fakechan);
 	fkchan_kill(d->fakechan);
 
-	sndstat_unregister(dev);
 	snd_mtxunlock(d->lock);
 	snd_mtxfree(d->lock);
+	sndstat_unregister(dev);
+	sndstat_release();
 	return 0;
 }