[PATCH 5.4 006/168] net: stmmac: fix notifier registration

Greg Kroah-Hartman
2020-03-10T13:33:03Z

From: Aaro Koskinen <aaro.koskinen@nokia.com>

[ Upstream commit 474a31e13a4e9749fb3ee55794d69d0f17ee0998 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 582176d869c35..89a6ae2b17e35 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -4208,6 +4208,8 @@ 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);

@@ -4219,14 +4221,13 @@ 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 */
@@ -4728,14 +4729,14 @@ 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);
@@ -4955,6 +4956,7 @@ 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;
@@ -4963,6 +4965,7 @@ 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
}
--
2.20.1