net: stmmac: fix notifier registration

We cannot register the same netdev notifier multiple times when probing
stmmac devices. Register the notifier only once in module init, and also
make debugfs creation/deletion safe against simultaneous notifier call.

Fixes: 481a7d154cbb ("stmmac: debugfs entry name is not be changed when udev rename device name.")
Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 5836b21..7da18c9 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4405,6 +4405,8 @@ static void stmmac_init_fs(struct net_device *dev)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
 
+       rtnl_lock();
+
        /* Create per netdev entries */
        priv->dbgfs_dir = debugfs_create_dir(dev->name, stmmac_fs_dir);
 
@@ -4416,14 +4418,13 @@ static void stmmac_init_fs(struct net_device *dev)
        debugfs_create_file("dma_cap", 0444, priv->dbgfs_dir, dev,
                            &stmmac_dma_cap_fops);
 
-       register_netdevice_notifier(&stmmac_notifier);
+       rtnl_unlock();
 }
 
 static void stmmac_exit_fs(struct net_device *dev)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
 
-       unregister_netdevice_notifier(&stmmac_notifier);
        debugfs_remove_recursive(priv->dbgfs_dir);
 }
 #endif /* CONFIG_DEBUG_FS */
@@ -4940,14 +4941,14 @@ int stmmac_dvr_remove(struct device *dev)
 
        netdev_info(priv->dev, "%s: removing driver", __func__);
 
-#ifdef CONFIG_DEBUG_FS
-       stmmac_exit_fs(ndev);
-#endif
        stmmac_stop_all_dma(priv);
 
        stmmac_mac_set(priv, priv->ioaddr, false);
        netif_carrier_off(ndev);
        unregister_netdev(ndev);
+#ifdef CONFIG_DEBUG_FS
+       stmmac_exit_fs(ndev);
+#endif
        phylink_destroy(priv->phylink);
        if (priv->plat->stmmac_rst)
                reset_control_assert(priv->plat->stmmac_rst);
@@ -5166,6 +5167,7 @@ static int __init stmmac_init(void)
        /* Create debugfs main directory if it doesn't exist yet */
        if (!stmmac_fs_dir)
                stmmac_fs_dir = debugfs_create_dir(STMMAC_RESOURCE_NAME, NULL);
+       register_netdevice_notifier(&stmmac_notifier);
 #endif
 
        return 0;
@@ -5174,6 +5176,7 @@ static int __init stmmac_init(void)
 static void __exit stmmac_exit(void)
 {
 #ifdef CONFIG_DEBUG_FS
+       unregister_netdevice_notifier(&stmmac_notifier);
        debugfs_remove_recursive(stmmac_fs_dir);
 #endif
 }