ipq806x: fix broken stmmac notifier

Backport a patch in 5.6 to fix stmmac notifier
registration

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>

1 files changed, 84 insertions, 0 deletions

diff --git a/target/linux/ipq806x/patches-5.4/701-stmmac-fix-notifier-registration.patch b/target/linux/ipq806x/patches-5.4/701-stmmac-fix-notifier-registration.patch
new file mode 100644
index 0000000000..187cbacde0
--- /dev/null
+++ b/target/linux/ipq806x/patches-5.4/701-stmmac-fix-notifier-registration.patch
@@ -0,0 +1,84 @@
+From 474a31e13a4e9749fb3ee55794d69d0f17ee0998 Mon Sep 17 00:00:00 2001
+From: Aaro Koskinen <aaro.koskinen@nokia.com>
+Date: Wed, 26 Feb 2020 18:49:01 +0200
+Subject: 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>
+---
+ drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 13 ++++++++-----
+ 1 file changed, 8 insertions(+), 5 deletions(-)
+
+(limited to 'drivers/net/ethernet/stmicro/stmmac')
+
+diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+index 5836b21edd7e..7da18c9afa01 100644
+--- 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
+ }
+-- 
+cgit 1.2-0.3.lf.el7
+