diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index b896c5559524..d6e2bb49c59c 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -141,7 +141,7 @@ int snd_usb_endpoint_implict_feedback_sink(struct snd_usb_endpoint *ep)
  *
  * For implicit feedback, next_packet_size() is unused.
  */
-static int next_packet_size(struct snd_usb_endpoint *ep)
+int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep)
 {
 	unsigned long flags;
 	int ret;
@@ -177,15 +177,6 @@ static void retire_inbound_urb(struct snd_usb_endpoint *ep,
 		ep->retire_data_urb(ep->data_subs, urb);
 }
 
-static void prepare_outbound_urb_sizes(struct snd_usb_endpoint *ep,
-				       struct snd_urb_ctx *ctx)
-{
-	int i;
-
-	for (i = 0; i < ctx->packets; ++i)
-		ctx->packet_size[i] = next_packet_size(ep);
-}
-
 /*
  * Prepare a PLAYBACK urb for submission to the bus.
  */
@@ -370,7 +361,6 @@ static void snd_complete_urb(struct urb *urb)
 			goto exit_clear;
 		}
 
-		prepare_outbound_urb_sizes(ep, ctx);
 		prepare_outbound_urb(ep, ctx);
 	} else {
 		retire_inbound_urb(ep, ctx);
@@ -857,7 +847,6 @@ int snd_usb_endpoint_start(struct snd_usb_endpoint *ep, int can_sleep)
 			goto __error;
 
 		if (usb_pipeout(ep->pipe)) {
-			prepare_outbound_urb_sizes(ep, urb->context);
 			prepare_outbound_urb(ep, urb->context);
 		} else {
 			prepare_inbound_urb(ep, urb->context);
diff --git a/sound/usb/endpoint.h b/sound/usb/endpoint.h
index a8e60c1408e5..cbbbdf226d66 100644
--- a/sound/usb/endpoint.h
+++ b/sound/usb/endpoint.h
@@ -21,6 +21,7 @@ int  snd_usb_endpoint_deactivate(struct snd_usb_endpoint *ep);
 void snd_usb_endpoint_free(struct list_head *head);
 
 int snd_usb_endpoint_implict_feedback_sink(struct snd_usb_endpoint *ep);
+int snd_usb_endpoint_next_packet_size(struct snd_usb_endpoint *ep);
 
 void snd_usb_handle_sync_urb(struct snd_usb_endpoint *ep,
 			     struct snd_usb_endpoint *sender,
diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c
index 5ceb8f1d63fb..e80b6687f43a 100644
--- a/sound/usb/pcm.c
+++ b/sound/usb/pcm.c
@@ -1029,6 +1029,7 @@ static void prepare_playback_urb(struct snd_usb_substream *subs,
 				 struct urb *urb)
 {
 	struct snd_pcm_runtime *runtime = subs->pcm_substream->runtime;
+	struct snd_usb_endpoint *ep = subs->data_endpoint;
 	struct snd_urb_ctx *ctx = urb->context;
 	unsigned int counts, frames, bytes;
 	int i, stride, period_elapsed = 0;
@@ -1040,7 +1041,11 @@ static void prepare_playback_urb(struct snd_usb_substream *subs,
 	urb->number_of_packets = 0;
 	spin_lock_irqsave(&subs->lock, flags);
 	for (i = 0; i < ctx->packets; i++) {
-		counts = ctx->packet_size[i];
+		if (ctx->packet_size[i])
+			counts = ctx->packet_size[i];
+		else
+			counts = snd_usb_endpoint_next_packet_size(ep);
+
 		/* set up descriptor */
 		urb->iso_frame_desc[i].offset = frames * stride;
 		urb->iso_frame_desc[i].length = counts * stride;