diff options
Diffstat (limited to 'target/linux/mvebu/patches-4.4/047-net-mvneta-Fix-spinlock-usage.patch')
| -rw-r--r-- | target/linux/mvebu/patches-4.4/047-net-mvneta-Fix-spinlock-usage.patch | 52 |
1 files changed, 52 insertions, 0 deletions
diff --git a/target/linux/mvebu/patches-4.4/047-net-mvneta-Fix-spinlock-usage.patch b/target/linux/mvebu/patches-4.4/047-net-mvneta-Fix-spinlock-usage.patch new file mode 100644 index 0000000000..a8e78df2e9 --- /dev/null +++ b/target/linux/mvebu/patches-4.4/047-net-mvneta-Fix-spinlock-usage.patch @@ -0,0 +1,52 @@ +From: Gregory CLEMENT <gregory.clement@free-electrons.com> +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 <patrick@puiterwijk.org> +Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + +--- a/drivers/net/ethernet/marvell/mvneta.c ++++ b/drivers/net/ethernet/marvell/mvneta.c +@@ -3484,17 +3484,17 @@ 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); +@@ -4027,6 +4027,7 @@ 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; + |