1 files changed, 47 insertions, 23 deletions

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 8c8f9a851f89..48a3843a08f1 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -39,7 +39,9 @@ struct snd_usb_iface_ref {
 struct snd_usb_clock_ref {
 	unsigned char clock;
 	atomic_t locked;
+	int opened;
 	int rate;
+	bool need_setup;
 	struct list_head list;
 };
 
@@ -93,12 +95,13 @@ static inline unsigned get_usb_high_speed_rate(unsigned int rate)
  */
 static void release_urb_ctx(struct snd_urb_ctx *u)
 {
-	if (u->buffer_size)
+	if (u->urb && u->buffer_size)
 		usb_free_coherent(u->ep->chip->dev, u->buffer_size,
 				  u->urb->transfer_buffer,
 				  u->urb->transfer_dma);
 	usb_free_urb(u->urb);
 	u->urb = NULL;
+	u->buffer_size = 0;
 }
 
 static const char *usb_error_string(int err)
@@ -802,6 +805,7 @@ snd_usb_endpoint_open(struct snd_usb_audio *chip,
 				ep = NULL;
 				goto unlock;
 			}
+			ep->clock_ref->opened++;
 		}
 
 		ep->cur_audiofmt = fp;
@@ -925,8 +929,10 @@ void snd_usb_endpoint_close(struct snd_usb_audio *chip,
 		endpoint_set_interface(chip, ep, false);
 
 	if (!--ep->opened) {
-		if (ep->clock_ref && !atomic_read(&ep->clock_ref->locked))
-			ep->clock_ref->rate = 0;
+		if (ep->clock_ref) {
+			if (!--ep->clock_ref->opened)
+				ep->clock_ref->rate = 0;
+		}
 		ep->iface = 0;
 		ep->altsetting = 0;
 		ep->cur_audiofmt = NULL;
@@ -1262,6 +1268,7 @@ static int sync_ep_set_params(struct snd_usb_endpoint *ep)
 	if (!ep->syncbuf)
 		return -ENOMEM;
 
+	ep->nurbs = SYNC_URBS;
 	for (i = 0; i < SYNC_URBS; i++) {
 		struct snd_urb_ctx *u = &ep->urb[i];
 		u->index = i;
@@ -1281,8 +1288,6 @@ static int sync_ep_set_params(struct snd_usb_endpoint *ep)
 		u->urb->complete = snd_complete_urb;
 	}
 
-	ep->nurbs = SYNC_URBS;
-
 	return 0;
 
 out_of_memory:
@@ -1290,6 +1295,29 @@ out_of_memory:
 	return -ENOMEM;
 }
 
+/* update the rate of the referred clock; return the actual rate */
+static int update_clock_ref_rate(struct snd_usb_audio *chip,
+				 struct snd_usb_endpoint *ep)
+{
+	struct snd_usb_clock_ref *clock = ep->clock_ref;
+	int rate = ep->cur_rate;
+
+	if (!clock || clock->rate == rate)
+		return rate;
+	if (clock->rate) {
+		if (atomic_read(&clock->locked))
+			return clock->rate;
+		if (clock->rate != rate) {
+			usb_audio_err(chip, "Mismatched sample rate %d vs %d for EP 0x%x\n",
+				      clock->rate, rate, ep->ep_num);
+			return clock->rate;
+		}
+	}
+	clock->rate = rate;
+	clock->need_setup = true;
+	return rate;
+}
+
 /*
  * snd_usb_endpoint_set_params: configure an snd_usb_endpoint
  *
@@ -1351,33 +1379,30 @@ int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
 	ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
 	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
 
-	return 0;
+	return update_clock_ref_rate(chip, ep);
 }
 
 static int init_sample_rate(struct snd_usb_audio *chip,
 			    struct snd_usb_endpoint *ep)
 {
 	struct snd_usb_clock_ref *clock = ep->clock_ref;
-	int err;
+	int rate, err;
 
-	if (clock) {
-		if (atomic_read(&clock->locked))
-			return 0;
-		if (clock->rate == ep->cur_rate)
-			return 0;
-		if (clock->rate && clock->rate != ep->cur_rate) {
-			usb_audio_dbg(chip, "Mismatched sample rate %d vs %d for EP 0x%x\n",
-				      clock->rate, ep->cur_rate, ep->ep_num);
-			return -EINVAL;
-		}
-	}
+	rate = update_clock_ref_rate(chip, ep);
+	if (rate < 0)
+		return rate;
+	if (clock && !clock->need_setup)
+		return 0;
 
-	err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, ep->cur_rate);
-	if (err < 0)
+	err = snd_usb_init_sample_rate(chip, ep->cur_audiofmt, rate);
+	if (err < 0) {
+		if (clock)
+			clock->rate = 0; /* reset rate */
 		return err;
+	}
 
 	if (clock)
-		clock->rate = ep->cur_rate;
+		clock->need_setup = false;
 	return 0;
 }
 
@@ -1628,8 +1653,7 @@ void snd_usb_endpoint_stop(struct snd_usb_endpoint *ep, bool keep_pending)
 			WRITE_ONCE(ep->sync_source->sync_sink, NULL);
 		stop_urbs(ep, false, keep_pending);
 		if (ep->clock_ref)
-			if (!atomic_dec_return(&ep->clock_ref->locked))
-				ep->clock_ref->rate = 0;
+			atomic_dec(&ep->clock_ref->locked);
 	}
 }