diff --git a/drivers/staging/greybus/es1-ap-usb.c b/drivers/staging/greybus/es1-ap-usb.c
index 88436436fcb2..f32c981d184c 100644
--- a/drivers/staging/greybus/es1-ap-usb.c
+++ b/drivers/staging/greybus/es1-ap-usb.c
@@ -407,9 +407,18 @@ static void cport_out_callback(struct urb *urb)
 	struct greybus_host_device *hd = urb->context;
 	struct es1_ap_dev *es1 = hd_to_es1(hd);
 	unsigned long flags;
-	/* int status = check_urb_status(urb); */
+	int status = check_urb_status(urb);
+	u8 *data = urb->transfer_buffer + 1;
 	int i;
 
+	/*
+	 * Tell the submitter that the buffer send (attempt) is
+	 * complete, and report the status.  The submitter's buffer
+	 * starts after the one-byte CPort id we inserted.
+	 */
+	data = urb->transfer_buffer + 1;
+	greybus_data_sent(hd, data, status);
+
 	/*
 	 * See if this was an urb in our pool, if so mark it "free", otherwise
 	 * we need to free it ourselves.
diff --git a/drivers/staging/greybus/operation.c b/drivers/staging/greybus/operation.c
index c9988fd790e3..74dd48a5a489 100644
--- a/drivers/staging/greybus/operation.c
+++ b/drivers/staging/greybus/operation.c
@@ -229,6 +229,24 @@ static void operation_timeout(struct work_struct *work)
 	gb_operation_complete(operation);
 }
 
+/*
+ * Given a pointer to the header in a message sent on a given host
+ * device, return the associated message structure.  (This "header"
+ * is just the buffer pointer we supply to the host device for
+ * sending.)
+ */
+static struct gb_message *
+gb_hd_message_find(struct greybus_host_device *hd, void *header)
+{
+	struct gb_message *message;
+	u8 *result;
+
+	result = (u8 *)header - hd->buffer_headroom - sizeof(*message);
+	message = (struct gb_message *)result;
+
+	return message;
+}
+
 /*
  * Allocate a message to be used for an operation request or
  * response.  For outgoing messages, both types of message contain a
@@ -473,6 +491,32 @@ int gb_operation_response_send(struct gb_operation *operation)
 	return 0;
 }
 
+/*
+ * This function is called when a buffer send request has completed.
+ * The "header" is the message header--the beginning of what we
+ * asked to have sent.
+ *
+ * XXX Mismatch between errno here and operation result code
+ */
+void
+greybus_data_sent(struct greybus_host_device *hd, void *header, int status)
+{
+	struct gb_message *message;
+	struct gb_operation *operation;
+
+	/* If there's no error, there's really nothing to do */
+	if (!status)
+		return;	/* Mark it complete? */
+
+	/* XXX Right now we assume we're an outgoing request */
+	message = gb_hd_message_find(hd, header);
+	operation = message->operation;
+	gb_connection_err(operation->connection, "send error %d\n", status);
+	operation->result = status;	/* XXX */
+	gb_operation_complete(operation);
+}
+EXPORT_SYMBOL_GPL(greybus_data_sent);
+
 /*
  * We've received data on a connection, and it doesn't look like a
  * response, so we assume it's a request.
diff --git a/drivers/staging/greybus/operation.h b/drivers/staging/greybus/operation.h
index 2fdb41c154a8..3e5e1f570f3e 100644
--- a/drivers/staging/greybus/operation.h
+++ b/drivers/staging/greybus/operation.h
@@ -103,6 +103,9 @@ int gb_operation_wait(struct gb_operation *operation);
 
 int gb_operation_status_map(u8 status);
 
+void greybus_data_sent(struct greybus_host_device *hd,
+				void *header, int status);
+
 int gb_operation_init(void);
 void gb_operation_exit(void);