qmi_wwan: avoid RCU stalls on device disconnect when in QMAP mode (a8fdde1c) · Commits · 戴 / test

drivers/net/usb/qmi_wwan.c

+7 −4

Original line number	Diff line number	Diff line
		@@ -312,14 +312,15 @@ out_free_newdev:
		return err;
		}

		static void qmimux_unregister_device(struct net_device *dev)
		static void qmimux_unregister_device(struct net_device *dev,
		struct list_head *head)
		{
		struct qmimux_priv *priv = netdev_priv(dev);
		struct net_device *real_dev = priv->real_dev;

		free_percpu(priv->stats64);
		netdev_upper_dev_unlink(real_dev, dev);
		unregister_netdevice(dev);
		unregister_netdevice_queue(dev, head);

		/* Get rid of the reference to real_dev */
		dev_put(real_dev);
		@@ -490,7 +491,7 @@ static ssize_t del_mux_store(struct device d, struct device_attribute attr, c
		ret = -EINVAL;
		goto err;
		}
		qmimux_unregister_device(del_dev);
		qmimux_unregister_device(del_dev, NULL);

		if (!qmimux_has_slaves(dev))
		info->flags &= ~QMI_WWAN_FLAG_MUX;
		@@ -1500,6 +1501,7 @@ static void qmi_wwan_disconnect(struct usb_interface *intf)
		struct qmi_wwan_state *info;
		struct list_head *iter;
		struct net_device *ldev;
		LIST_HEAD(list);

		/* called twice if separate control and data intf */
		if (!dev)
		@@ -1512,8 +1514,9 @@ static void qmi_wwan_disconnect(struct usb_interface *intf)
		}
		rcu_read_lock();
		netdev_for_each_upper_dev_rcu(dev->net, ldev, iter)
		qmimux_unregister_device(ldev);
		qmimux_unregister_device(ldev, &list);
		rcu_read_unlock();
		unregister_netdevice_many(&list);
		rtnl_unlock();
		info->flags &= ~QMI_WWAN_FLAG_MUX;
		}