From 1c2722a975fdb8c90bc6ba8570b7fb62db4e2e9c Mon Sep 17 00:00:00 2001 From: Gregory CLEMENT Date: Sat, 12 Mar 2016 18:44:17 +0100 Subject: [PATCH] net: mvneta: Fix spinlock usage 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 Signed-off-by: Gregory CLEMENT Signed-off-by: David S. Miller --- drivers/net/ethernet/marvell/mvneta.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index be92668faf3e..665eac2c2469 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c @@ -3480,17 +3480,17 @@ static int mvneta_stop(struct net_device *dev) 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); @@ -4023,6 +4023,7 @@ static int mvneta_probe(struct platform_device *pdev) 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;