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authorThomas Gleixner <tglx@linutronix.de>2009-11-17 12:02:43 +0100
committerThomas Gleixner <tglx@linutronix.de>2009-11-17 12:31:28 +0100
commit05d5f5080a2e3fbbc0f762875b66721588f5e251 (patch)
tree332eb77b70a6d8af672c29c6d0b63d5c80c41879
parent05d10b6e792d6fff7e70acd95e9c734ce20bf144 (diff)
net: at91_ether: Make mdio protection -rt safe
Neither the phy interrupt nor the timer callback which updates the link status in absense of a phy interrupt are taking lp->lock which serializes the MDIO access. This works on mainline as at91 is an UP machine. On preempt-rt the timer callback can run even in the spin_lock_irq(&lp->lock) protected code pathes because spin_lock_irq is neither disabling interrupts nor disabling preemption. Fix this by adding proper locking to at91ether_phy_interrupt() and at91_check_ether() which serializes the access on -rt. Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
-rw-r--r--drivers/net/arm/at91_ether.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/arm/at91_ether.c b/drivers/net/arm/at91_ether.c
index 5041d10bae9d..32399b6595cb 100644
--- a/drivers/net/arm/at91_ether.c
+++ b/drivers/net/arm/at91_ether.c
@@ -198,7 +198,9 @@ static irqreturn_t at91ether_phy_interrupt(int irq, void *dev_id)
struct net_device *dev = (struct net_device *) dev_id;
struct at91_private *lp = netdev_priv(dev);
unsigned int phy;
+ unsigned long flags;
+ spin_lock_irqsave(&lp->lock, flags);
/*
* This hander is triggered on both edges, but the PHY chips expect
* level-triggering. We therefore have to check if the PHY actually has
@@ -240,6 +242,7 @@ static irqreturn_t at91ether_phy_interrupt(int irq, void *dev_id)
done:
disable_mdi();
+ spin_unlock_irqrestore(&lp->lock, flags);
return IRQ_HANDLED;
}
@@ -396,9 +399,11 @@ static void at91ether_check_link(unsigned long dev_id)
struct net_device *dev = (struct net_device *) dev_id;
struct at91_private *lp = netdev_priv(dev);
+ spin_lock_irq(&lp->lock);
enable_mdi();
update_linkspeed(dev, 1);
disable_mdi();
+ spin_unlock_irq(&lp->lock);
mod_timer(&lp->check_timer, jiffies + LINK_POLL_INTERVAL);
}