diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2009-11-17 12:02:43 +0100 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-03-01 09:28:26 -0600 |
| commit | dd564e6edcc6eec912e79bef07982680d967d659 (patch) | |
| tree | a27ed07cded5a658cce8522fd68f7ab040a6ef3a /drivers | |
| parent | 0e74c9fddc2dca2865f01c404974d49ca29d9854 (diff) | |
drivers: 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>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/cadence/at91_ether.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/net/ethernet/cadence/at91_ether.c b/drivers/net/ethernet/cadence/at91_ether.c index 56624d303487..ad4dbea804d4 100644 --- a/drivers/net/ethernet/cadence/at91_ether.c +++ b/drivers/net/ethernet/cadence/at91_ether.c @@ -200,7 +200,9 @@ 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 @@ -242,6 +244,7 @@ static irqreturn_t at91ether_phy_interrupt(int irq, void *dev_id) done: disable_mdi(); + spin_unlock_irqrestore(&lp->lock, flags); return IRQ_HANDLED; } @@ -398,9 +401,11 @@ 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); } |