diff --git a/sound/usb/card.h b/sound/usb/card.h
index 2b9ffff..d5c2e3a 100644
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -123,6 +123,7 @@ struct snd_usb_substream {
 	struct snd_usb_endpoint *data_endpoint;
 	struct snd_usb_endpoint *sync_endpoint;
 	unsigned long flags;
+	unsigned int speed;		/* USB_SPEED_XXX */

 	u64 formats;			/* format bitmasks (all or'ed) */
 	unsigned int num_formats;		/* number of supported audio formats (list) */
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index fe56c9d..c2ef11c 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -287,25 +287,32 @@ static int get_ctl_value_v1(struct usb_mixer_elem_info *cval, int request, int v
 	unsigned char buf[2];
 	int val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
 	int timeout = 10;
-	int err;
+	int idx = 0, err;

 	err = snd_usb_autoresume(cval->mixer->chip);
 	if (err < 0)
 		return -EIO;
+	mutex_lock(&chip->shutdown_mutex);
 	while (timeout-- > 0) {
+		if (chip->shutdown)
+			break;
+		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
 		if (snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), request,
 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
-				    validx, snd_usb_ctrl_intf(chip) | (cval->id << 8),
-				    buf, val_len) >= val_len) {
+				    validx, idx, buf, val_len) >= val_len) {
 			*value_ret = convert_signed_value(cval, snd_usb_combine_bytes(buf, val_len));
-			snd_usb_autosuspend(cval->mixer->chip);
-			return 0;
+			err = 0;
+			goto out;
 		}
 	}
-	snd_usb_autosuspend(cval->mixer->chip);
 	snd_printdd(KERN_ERR "cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
-		    request, validx, snd_usb_ctrl_intf(chip) | (cval->id << 8), cval->val_type);
-	return -EINVAL;
+		    request, validx, idx, cval->val_type);
+	err = -EINVAL;
+
+ out:
+	mutex_unlock(&chip->shutdown_mutex);
+	snd_usb_autosuspend(cval->mixer->chip);
+	return err;
 }

 static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int validx, int *value_ret)
@@ -313,7 +320,7 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int v
 	struct snd_usb_audio *chip = cval->mixer->chip;
 	unsigned char buf[2 + 3*sizeof(__u16)]; /* enough space for one range */
 	unsigned char *val;
-	int ret, size;
+	int idx = 0, ret, size;
 	__u8 bRequest;

 	if (request == UAC_GET_CUR) {
@@ -330,16 +337,22 @@ static int get_ctl_value_v2(struct usb_mixer_elem_info *cval, int request, int v
 	if (ret)
 		goto error;

-	ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
+	mutex_lock(&chip->shutdown_mutex);
+	if (chip->shutdown)
+		ret = -ENODEV;
+	else {
+		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
+		ret = snd_usb_ctl_msg(chip->dev, usb_rcvctrlpipe(chip->dev, 0), bRequest,
 			      USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_IN,
-			      validx, snd_usb_ctrl_intf(chip) | (cval->id << 8),
-			      buf, size);
+			      validx, idx, buf, size);
+	}
+	mutex_unlock(&chip->shutdown_mutex);
 	snd_usb_autosuspend(chip);

 	if (ret < 0) {
 error:
 		snd_printk(KERN_ERR "cannot get ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d\n",
-			   request, validx, snd_usb_ctrl_intf(chip) | (cval->id << 8), cval->val_type);
+			   request, validx, idx, cval->val_type);
 		return ret;
 	}

@@ -417,7 +430,7 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
 {
 	struct snd_usb_audio *chip = cval->mixer->chip;
 	unsigned char buf[2];
-	int val_len, err, timeout = 10;
+	int idx = 0, val_len, err, timeout = 10;

 	if (cval->mixer->protocol == UAC_VERSION_1) {
 		val_len = cval->val_type >= USB_MIXER_S16 ? 2 : 1;
@@ -440,19 +453,27 @@ int snd_usb_mixer_set_ctl_value(struct usb_mixer_elem_info *cval,
 	err = snd_usb_autoresume(chip);
 	if (err < 0)
 		return -EIO;
-	while (timeout-- > 0)
+	mutex_lock(&chip->shutdown_mutex);
+	while (timeout-- > 0) {
+		if (chip->shutdown)
+			break;
+		idx = snd_usb_ctrl_intf(chip) | (cval->id << 8);
 		if (snd_usb_ctl_msg(chip->dev,
 				    usb_sndctrlpipe(chip->dev, 0), request,
 				    USB_RECIP_INTERFACE | USB_TYPE_CLASS | USB_DIR_OUT,
-				    validx, snd_usb_ctrl_intf(chip) | (cval->id << 8),
-				    buf, val_len) >= 0) {
-			snd_usb_autosuspend(chip);
-			return 0;
+				    validx, idx, buf, val_len) >= 0) {
+			err = 0;
+			goto out;
 		}
-	snd_usb_autosuspend(chip);
+	}
 	snd_printdd(KERN_ERR "cannot set ctl value: req = %#x, wValue = %#x, wIndex = %#x, type = %d, data = %#x/%#x\n",
-		    request, validx, snd_usb_ctrl_intf(chip) | (cval->id << 8), cval->val_type, buf[0], buf[1]);
-	return -EINVAL;
+		    request, validx, idx, cval->val_type, buf[0], buf[1]);
+	err = -EINVAL;
+
+ out:
+	mutex_unlock(&chip->shutdown_mutex);
+	snd_usb_autosuspend(chip);
+	return err;
 }

 static int set_cur_ctl_value(struct usb_mixer_elem_info *cval, int validx, int value)
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index f782ce1..0de406a 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -71,6 +71,8 @@ static snd_pcm_uframes_t snd_usb_pcm_pointer(struct snd_pcm_substream *substream
 	unsigned int hwptr_done;

 	subs = (struct snd_usb_substream *)substream->runtime->private_data;
+	if (subs->stream->chip->shutdown)
+		return SNDRV_PCM_POS_XRUN;
 	spin_lock(&subs->lock);
 	hwptr_done = subs->hwptr_done;
 	substream->runtime->delay = snd_usb_pcm_delay(subs,
@@ -471,8 +473,14 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 	changed = subs->cur_audiofmt != fmt ||
 		subs->period_bytes != params_period_bytes(hw_params) ||
 		subs->cur_rate != rate;
+
+	mutex_lock(&subs->stream->chip->shutdown_mutex);
+	if (subs->stream->chip->shutdown) {
+		ret = -ENODEV;
+		goto unlock;
+	}
 	if ((ret = set_format(subs, fmt)) < 0)
-		return ret;
+		goto unlock;

 	if (subs->cur_rate != rate) {
 		struct usb_host_interface *alts;
@@ -481,12 +489,11 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		alts = &iface->altsetting[fmt->altset_idx];
 		ret = snd_usb_init_sample_rate(subs->stream->chip, fmt->iface, alts, fmt, rate);
 		if (ret < 0)
-			return ret;
+			goto unlock;
 		subs->cur_rate = rate;
 	}

 	if (changed) {
-		mutex_lock(&subs->stream->chip->shutdown_mutex);
 		/* format changed */
 		stop_endpoints(subs, 0, 0, 0);
 		ret = snd_usb_endpoint_set_params(subs->data_endpoint, hw_params, fmt,
@@ -497,8 +504,6 @@ static int snd_usb_hw_params(struct snd_pcm_substream *substream,
 		if (subs->sync_endpoint)
 			ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
 							  hw_params, fmt, NULL);
-unlock:
-		mutex_unlock(&subs->stream->chip->shutdown_mutex);
 	}

 	if (ret == 0) {
@@ -506,6 +511,8 @@ unlock:
 		subs->altset_idx = fmt->altset_idx;
 	}

+unlock:
+	mutex_unlock(&subs->stream->chip->shutdown_mutex);
 	return ret;
 }

@@ -522,8 +529,10 @@ static int snd_usb_hw_free(struct snd_pcm_substream *substream)
 	subs->cur_rate = 0;
 	subs->period_bytes = 0;
 	mutex_lock(&subs->stream->chip->shutdown_mutex);
-	stop_endpoints(subs, 0, 1, 1);
-	deactivate_endpoints(subs);
+	if (!subs->stream->chip->shutdown) {
+		stop_endpoints(subs, 0, 1, 1);
+		deactivate_endpoints(subs);
+	}
 	mutex_unlock(&subs->stream->chip->shutdown_mutex);
 	return snd_pcm_lib_free_vmalloc_buffer(substream);
 }
@@ -537,14 +546,22 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_usb_substream *subs = runtime->private_data;
+	int ret = 0;

 	if (! subs->cur_audiofmt) {
 		snd_printk(KERN_ERR "usbaudio: no format is specified!\n");
 		return -ENXIO;
 	}

-	if (snd_BUG_ON(!subs->data_endpoint))
-		return -EIO;
+	mutex_lock(&subs->stream->chip->shutdown_mutex);
+	if (subs->stream->chip->shutdown) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+	if (snd_BUG_ON(!subs->data_endpoint)) {
+		ret = -EIO;
+		goto unlock;
+	}

 	/* some unit conversions in runtime */
 	subs->data_endpoint->maxframesize =
@@ -562,9 +579,11 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
 	/* for playback, submit the URBs now; otherwise, the first hwptr_done
 	 * updates for all URBs would happen at the same time when starting */
 	if (subs->direction == SNDRV_PCM_STREAM_PLAYBACK)
-		return start_endpoints(subs, 1);
+		ret = start_endpoints(subs, 1);

-	return 0;
+ unlock:
+	mutex_unlock(&subs->stream->chip->shutdown_mutex);
+	return ret;
 }

 static struct snd_pcm_hardware snd_usb_hardware =
@@ -617,7 +636,7 @@ static int hw_check_valid_format(struct snd_usb_substream *subs,
 		return 0;
 	}
 	/* check whether the period time is >= the data packet interval */
-	if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL) {
+	if (subs->speed != USB_SPEED_FULL) {
 		ptime = 125 * (1 << fp->datainterval);
 		if (ptime > pt->max || (ptime == pt->max && pt->openmax)) {
 			hwc_debug("   > check: ptime %u > max %u\n", ptime, pt->max);
@@ -895,7 +914,7 @@ static int setup_hw_info(struct snd_pcm_runtime *runtime, struct snd_usb_substre
 		return err;

 	param_period_time_if_needed = SNDRV_PCM_HW_PARAM_PERIOD_TIME;
-	if (snd_usb_get_speed(subs->dev) == USB_SPEED_FULL)
+	if (subs->speed == USB_SPEED_FULL)
 		/* full speed devices have fixed data packet interval */
 		ptmin = 1000;
 	if (ptmin == 1000)
diff --git a/sound/usb/proc.c b/sound/usb/proc.c
index ebc1a5b..d218f76 100644
--- a/sound/usb/proc.c
+++ b/sound/usb/proc.c
@@ -108,7 +108,7 @@ static void proc_dump_substream_formats(struct snd_usb_substream *subs, struct s
 			}
 			snd_iprintf(buffer, "\n");
 		}
-		if (snd_usb_get_speed(subs->dev) != USB_SPEED_FULL)
+		if (subs->speed != USB_SPEED_FULL)
 			snd_iprintf(buffer, "    Data packet interval: %d us\n",
 				    125 * (1 << fp->datainterval));
 		// snd_iprintf(buffer, "    Max Packet Size = %d\n", fp->maxpacksize);
@@ -124,7 +124,7 @@ static void proc_dump_ep_status(struct snd_usb_substream *subs,
 		return;
 	snd_iprintf(buffer, "    Packet Size = %d\n", ep->curpacksize);
 	snd_iprintf(buffer, "    Momentary freq = %u Hz (%#x.%04x)\n",
-		    snd_usb_get_speed(subs->dev) == USB_SPEED_FULL
+		    subs->speed == USB_SPEED_FULL
 		    ? get_full_speed_hz(ep->freqm)
 		    : get_high_speed_hz(ep->freqm),
 		    ep->freqm >> 16, ep->freqm & 0xffff);
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index 083ed81..1de0c8c 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -90,6 +90,7 @@ static void snd_usb_init_substream(struct snd_usb_stream *as,
 	subs->direction = stream;
 	subs->dev = as->chip->dev;
 	subs->txfr_quirk = as->chip->txfr_quirk;
+	subs->speed = snd_usb_get_speed(subs->dev);

 	snd_usb_set_pcm_ops(as->pcm, stream);