[PATCH net 1/3] net: mvneta: Fix spinlock usage
From: Gregory CLEMENT <hidden>
Date: 2016-03-08 12:58:20
Also in:
lkml, netdev
Subsystem:
marvell mvneta ethernet driver, networking drivers, the rest · Maintainers:
Marcin Wojtas, Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
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 <redacted> Signed-off-by: Gregory CLEMENT <redacted> --- 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 b0ae69f84493..8dc7df2edff6 100644
--- 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 *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);
@@ -3612,6 +3612,7 @@ 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;
--
2.5.0