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53 lines
1.9 KiB
53 lines
1.9 KiB
9 years ago
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From: Gregory CLEMENT <gregory.clement@free-electrons.com>
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Date: Sat, 12 Mar 2016 18:44:17 +0100
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Subject: [PATCH] net: mvneta: Fix spinlock usage
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In the previous patch, the spinlock was not initialized. While it didn't
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cause any trouble yet it could be a problem to use it uninitialized.
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The most annoying part was the critical section protected by the spinlock
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in mvneta_stop(). Some of the functions could sleep as pointed when
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activated CONFIG_DEBUG_ATOMIC_SLEEP. Actually, in mvneta_stop() we only
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need to protect the is_stopped flagged, indeed the code of the notifier
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for CPU online is protected by the same spinlock, so when we get the
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lock, the notifer work is done.
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Reported-by: Patrick Uiterwijk <patrick@puiterwijk.org>
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Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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--- a/drivers/net/ethernet/marvell/mvneta.c
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+++ b/drivers/net/ethernet/marvell/mvneta.c
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@@ -3484,17 +3484,17 @@ static int mvneta_stop(struct net_device
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struct mvneta_port *pp = netdev_priv(dev);
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/* Inform that we are stopping so we don't want to setup the
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- * driver for new CPUs in the notifiers
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+ * driver for new CPUs in the notifiers. The code of the
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+ * notifier for CPU online is protected by the same spinlock,
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+ * so when we get the lock, the notifer work is done.
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*/
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spin_lock(&pp->lock);
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pp->is_stopped = true;
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+ spin_unlock(&pp->lock);
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+
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mvneta_stop_dev(pp);
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mvneta_mdio_remove(pp);
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unregister_cpu_notifier(&pp->cpu_notifier);
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- /* Now that the notifier are unregistered, we can release le
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- * lock
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- */
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- spin_unlock(&pp->lock);
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on_each_cpu(mvneta_percpu_disable, pp, true);
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free_percpu_irq(dev->irq, pp->ports);
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mvneta_cleanup_rxqs(pp);
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@@ -4027,6 +4027,7 @@ static int mvneta_probe(struct platform_
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dev->ethtool_ops = &mvneta_eth_tool_ops;
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pp = netdev_priv(dev);
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+ spin_lock_init(&pp->lock);
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pp->phy_node = phy_node;
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pp->phy_interface = phy_mode;
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