1 files changed, 25 insertions, 7 deletions

diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 48a3843a08f1..d0b8d61d1d22 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -32,6 +32,7 @@ struct snd_usb_iface_ref {
 	unsigned char iface;
 	bool need_setup;
 	int opened;
+	int altset;
 	struct list_head list;
 };
 
@@ -823,6 +824,7 @@ snd_usb_endpoint_open(struct snd_usb_audio *chip,
 
 		ep->implicit_fb_sync = fp->implicit_fb;
 		ep->need_setup = true;
+		ep->need_prepare = true;
 
 		usb_audio_dbg(chip, "  channels=%d, rate=%d, format=%s, period_bytes=%d, periods=%d, implicit_fb=%d\n",
 			      ep->cur_channels, ep->cur_rate,
@@ -899,6 +901,9 @@ static int endpoint_set_interface(struct snd_usb_audio *chip,
 	int altset = set ? ep->altsetting : 0;
 	int err;
 
+	if (ep->iface_ref->altset == altset)
+		return 0;
+
 	usb_audio_dbg(chip, "Setting usb interface %d:%d for EP 0x%x\n",
 		      ep->iface, altset, ep->ep_num);
 	err = usb_set_interface(chip->dev, ep->iface, altset);
@@ -910,6 +915,7 @@ static int endpoint_set_interface(struct snd_usb_audio *chip,
 
 	if (chip->quirk_flags & QUIRK_FLAG_IFACE_DELAY)
 		msleep(50);
+	ep->iface_ref->altset = altset;
 	return 0;
 }
 
@@ -947,7 +953,7 @@ void snd_usb_endpoint_close(struct snd_usb_audio *chip,
 /* Prepare for suspening EP, called from the main suspend handler */
 void snd_usb_endpoint_suspend(struct snd_usb_endpoint *ep)
 {
-	ep->need_setup = true;
+	ep->need_prepare = true;
 	if (ep->iface_ref)
 		ep->iface_ref->need_setup = true;
 	if (ep->clock_ref)
@@ -1330,12 +1336,16 @@ int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
 				struct snd_usb_endpoint *ep)
 {
 	const struct audioformat *fmt = ep->cur_audiofmt;
-	int err;
+	int err = 0;
+
+	mutex_lock(&chip->mutex);
+	if (!ep->need_setup)
+		goto unlock;
 
 	/* release old buffers, if any */
 	err = release_urbs(ep, false);
 	if (err < 0)
-		return err;
+		goto unlock;
 
 	ep->datainterval = fmt->datainterval;
 	ep->maxpacksize = fmt->maxpacksize;
@@ -1373,13 +1383,21 @@ int snd_usb_endpoint_set_params(struct snd_usb_audio *chip,
 	usb_audio_dbg(chip, "Set up %d URBS, ret=%d\n", ep->nurbs, err);
 
 	if (err < 0)
-		return err;
+		goto unlock;
 
 	/* some unit conversions in runtime */
 	ep->maxframesize = ep->maxpacksize / ep->cur_frame_bytes;
 	ep->curframesize = ep->curpacksize / ep->cur_frame_bytes;
 
-	return update_clock_ref_rate(chip, ep);
+	err = update_clock_ref_rate(chip, ep);
+	if (err >= 0) {
+		ep->need_setup = false;
+		err = 0;
+	}
+
+ unlock:
+	mutex_unlock(&chip->mutex);
+	return err;
 }
 
 static int init_sample_rate(struct snd_usb_audio *chip,
@@ -1426,7 +1444,7 @@ int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
 	mutex_lock(&chip->mutex);
 	if (WARN_ON(!ep->iface_ref))
 		goto unlock;
-	if (!ep->need_setup)
+	if (!ep->need_prepare)
 		goto unlock;
 
 	/* If the interface has been already set up, just set EP parameters */
@@ -1480,7 +1498,7 @@ int snd_usb_endpoint_prepare(struct snd_usb_audio *chip,
 	ep->iface_ref->need_setup = false;
 
  done:
-	ep->need_setup = false;
+	ep->need_prepare = false;
 	err = 1;
 
 unlock: