5 files changed, 27 insertions, 6 deletions

diff --git a/sound/usb/card.c b/sound/usb/card.c
index 282f0fc9fed1..dbf7999d18b4 100644
--- a/sound/usb/card.c
+++ b/sound/usb/card.c
@@ -559,9 +559,11 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
                 return;
 
         card = chip->card;
-        mutex_lock(&register_mutex);
         down_write(&chip->shutdown_rwsem);
         chip->shutdown = 1;
+        up_write(&chip->shutdown_rwsem);
+
+        mutex_lock(&register_mutex);
         chip->num_interfaces--;
         if (chip->num_interfaces <= 0) {
                 snd_card_disconnect(card);
@@ -582,11 +584,9 @@ static void snd_usb_audio_disconnect(struct usb_device *dev,
                         snd_usb_mixer_disconnect(p);
                 }
                 usb_chip[chip->index] = NULL;
-                up_write(&chip->shutdown_rwsem);
                 mutex_unlock(&register_mutex);
                 snd_card_free_when_closed(card);
         } else {
-                up_write(&chip->shutdown_rwsem);
                 mutex_unlock(&register_mutex);
         }
 }
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 7f78c6d782b0..34de6f2faf61 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -35,6 +35,7 @@
 
 #define EP_FLAG_ACTIVATED       0
 #define EP_FLAG_RUNNING         1
+#define EP_FLAG_STOPPING        2
 
 /*
  * snd_usb_endpoint is a model that abstracts everything related to an
@@ -502,10 +503,20 @@ static int wait_clear_urbs(struct snd_usb_endpoint *ep)
         if (alive)
                 snd_printk(KERN_ERR "timeout: still %d active urbs on EP #%x\n",
                                         alive, ep->ep_num);
+        clear_bit(EP_FLAG_STOPPING, &ep->flags);
 
         return 0;
 }
 
+/* sync the pending stop operation;
+ * this function itself doesn't trigger the stop operation
+ */
+void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep)
+{
+        if (ep && test_bit(EP_FLAG_STOPPING, &ep->flags))
+                wait_clear_urbs(ep);
+}
+
 /*
  * unlink active urbs.
  */
@@ -918,6 +929,8 @@ void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep,
 
                 if (wait)
                         wait_clear_urbs(ep);
+                else
+                        set_bit(EP_FLAG_STOPPING, &ep->flags);
         }
 }
 
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
index 6376ccf10fd4..3d4c9705041f 100644
--- a/sound/usb/endpoint.h
+++ b/sound/usb/endpoint.h
@@ -19,6 +19,7 @@ int snd_usb_endpoint_set_params(struct snd_usb_endpoint *ep,
 int  snd_usb_endpoint_start(struct snd_usb_endpoint *ep, int can_sleep);
 void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep,
                            int force, int can_sleep, int wait);
+void snd_usb_endpoint_sync_pending_stop(struct snd_usb_endpoint *ep);
 int  snd_usb_endpoint_activate(struct snd_usb_endpoint *ep);
 int  snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep);
 void snd_usb_endpoint_free(struct list_head *head);
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index c83f6143c0eb..eeefbce3873c 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -148,6 +148,7 @@ struct snd_usb_midi_out_endpoint {
                 struct snd_usb_midi_out_endpoint* ep;
                 struct snd_rawmidi_substream *substream;
                 int active;
+                bool autopm_reference;
                 uint8_t cable;          /* cable number << 4 */
                 uint8_t state;
 #define STATE_UNKNOWN   0
@@ -1076,7 +1077,8 @@ static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
                 return -ENXIO;
         }
         err = usb_autopm_get_interface(umidi->iface);
-        if (err < 0)
+        port->autopm_reference = err >= 0;
+        if (err < 0 && err != -EACCES)
                 return -EIO;
         substream->runtime->private_data = port;
         port->state = STATE_UNKNOWN;
@@ -1087,9 +1089,11 @@ static int snd_usbmidi_output_open(struct snd_rawmidi_substream *substream)
 static int snd_usbmidi_output_close(struct snd_rawmidi_substream *substream)
 {
         struct snd_usb_midi* umidi = substream->rmidi->private_data;
+        struct usbmidi_out_port *port = substream->runtime->private_data;
 
         substream_open(substream, 0);
-        usb_autopm_put_interface(umidi->iface);
+        if (port->autopm_reference)
+                usb_autopm_put_interface(umidi->iface);
         return 0;
 }
 
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 37428f74dbb6..ef6fa24fc473 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -459,7 +459,7 @@ static int configure_endpoint(struct snd_usb_substream *subs)
                 return ret;
 
         if (subs->sync_endpoint)
-                ret = snd_usb_endpoint_set_params(subs->data_endpoint,
+                ret = snd_usb_endpoint_set_params(subs->sync_endpoint,
                                                   subs->pcm_format,
                                                   subs->channels,
                                                   subs->period_bytes,
@@ -568,6 +568,9 @@ static int snd_usb_pcm_prepare(struct snd_pcm_substream *substream)
                 goto unlock;
         }
 
+        snd_usb_endpoint_sync_pending_stop(subs->sync_endpoint);
+        snd_usb_endpoint_sync_pending_stop(subs->data_endpoint);
+
         ret = set_format(subs, subs->cur_audiofmt);
         if (ret < 0)
                 goto unlock;