1 files changed, 24 insertions, 13 deletions

diff --git a/drivers/usb/gadget/function/f_ecm.c b/drivers/usb/gadget/function/f_ecm.c
index 675d2bc538a4..e315f18b7f9f 100644
--- a/drivers/usb/gadget/function/f_ecm.c
+++ b/drivers/usb/gadget/function/f_ecm.c
@@ -681,6 +681,7 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 	struct usb_ep		*ep;
 
 	struct f_ecm_opts	*ecm_opts;
+	struct net_device	*net __free(detach_gadget) = NULL;
 	struct usb_request	*request __free(free_usb_request) = NULL;
 
 	if (!can_support_ecm(cdev->gadget))
@@ -688,18 +689,18 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 
 	ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
 
-	mutex_lock(&ecm_opts->lock);
-
-	gether_set_gadget(ecm_opts->net, cdev->gadget);
-
-	if (!ecm_opts->bound) {
-		status = gether_register_netdev(ecm_opts->net);
-		ecm_opts->bound = true;
-	}
-
-	mutex_unlock(&ecm_opts->lock);
-	if (status)
-		return status;
+	scoped_guard(mutex, &ecm_opts->lock)
+		if (ecm_opts->bind_count == 0 && !ecm_opts->bound) {
+			if (!device_is_registered(&ecm_opts->net->dev)) {
+				gether_set_gadget(ecm_opts->net, cdev->gadget);
+				status = gether_register_netdev(ecm_opts->net);
+			} else
+				status = gether_attach_gadget(ecm_opts->net, cdev->gadget);
+
+			if (status)
+				return status;
+			net = ecm_opts->net;
+		}
 
 	ecm_string_defs[1].s = ecm->ethaddr;
 
@@ -790,6 +791,9 @@ ecm_bind(struct usb_configuration *c, struct usb_function *f)
 
 	ecm->notify_req = no_free_ptr(request);
 
+	ecm_opts->bind_count++;
+	retain_and_null_ptr(net);
+
 	DBG(cdev, "CDC Ethernet: IN/%s OUT/%s NOTIFY/%s\n",
 			ecm->port.in_ep->name, ecm->port.out_ep->name,
 			ecm->notify->name);
@@ -836,7 +840,7 @@ static void ecm_free_inst(struct usb_function_instance *f)
 	struct f_ecm_opts *opts;
 
 	opts = container_of(f, struct f_ecm_opts, func_inst);
-	if (opts->bound)
+	if (device_is_registered(&opts->net->dev))
 		gether_cleanup(netdev_priv(opts->net));
 	else
 		free_netdev(opts->net);
@@ -906,9 +910,12 @@ static void ecm_free(struct usb_function *f)
 static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 {
 	struct f_ecm		*ecm = func_to_ecm(f);
+	struct f_ecm_opts	*ecm_opts;
 
 	DBG(c->cdev, "ecm unbind\n");
 
+	ecm_opts = container_of(f->fi, struct f_ecm_opts, func_inst);
+
 	usb_free_all_descriptors(f);
 
 	if (atomic_read(&ecm->notify_count)) {
@@ -918,6 +925,10 @@ static void ecm_unbind(struct usb_configuration *c, struct usb_function *f)
 
 	kfree(ecm->notify_req->buf);
 	usb_ep_free_request(ecm->notify, ecm->notify_req);
+
+	ecm_opts->bind_count--;
+	if (ecm_opts->bind_count == 0 && !ecm_opts->bound)
+		gether_detach_gadget(ecm_opts->net);
 }
 
 static struct usb_function *ecm_alloc(struct usb_function_instance *fi)