4.5-stable review patch. If anyone has any objections, please let me know.
------------------
From: Gregory CLEMENT <gregory.clem...@free-electrons.com>
[ Upstream commit 1c2722a975fdb8c90bc6ba8570b7fb62db4e2e9c ]
In the previous patch, the spinlock was not initialized. While it didn't
cause any trouble yet it could be a problem to use it uninitialized.
The most annoying part was the critical section protected by the spinlock
in mvneta_stop(). Some of the functions could sleep as pointed when
activated CONFIG_DEBUG_ATOMIC_SLEEP. Actually, in mvneta_stop() we only
need to protect the is_stopped flagged, indeed the code of the notifier
for CPU online is protected by the same spinlock, so when we get the
lock, the notifer work is done.
Reported-by: Patrick Uiterwijk <patr...@puiterwijk.org>
Signed-off-by: Gregory CLEMENT <gregory.clem...@free-electrons.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
drivers/net/ethernet/marvell/mvneta.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -3070,17 +3070,17 @@ static int mvneta_stop(struct net_device
struct mvneta_port *pp = netdev_priv(dev);
/* Inform that we are stopping so we don't want to setup the
- * driver for new CPUs in the notifiers
+ * driver for new CPUs in the notifiers. The code of the
+ * notifier for CPU online is protected by the same spinlock,
+ * so when we get the lock, the notifer work is done.
*/
spin_lock(&pp->lock);
pp->is_stopped = true;
+ spin_unlock(&pp->lock);
+
mvneta_stop_dev(pp);
mvneta_mdio_remove(pp);
unregister_cpu_notifier(&pp->cpu_notifier);
- /* Now that the notifier are unregistered, we can release le
- * lock
- */
- spin_unlock(&pp->lock);
on_each_cpu(mvneta_percpu_disable, pp, true);
free_percpu_irq(dev->irq, pp->ports);
mvneta_cleanup_rxqs(pp);
@@ -3612,6 +3612,7 @@ static int mvneta_probe(struct platform_
dev->ethtool_ops = &mvneta_eth_tool_ops;
pp = netdev_priv(dev);
+ spin_lock_init(&pp->lock);
pp->phy_node = phy_node;
pp->phy_interface = phy_mode;
