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Commit 1df726ef authored by Russell King's avatar Russell King
Browse files

NET: am79c961: fix race in link status code 



The link status code operates from a timer, and writes the index
register without first taking a lock.  A well-placed interrupt
between writing the index register and reading the data register
could change the index register on us, which will return wrong data.
Add the necessary lock.

Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent fb492c91

drivers/net/arm/am79c961a.c

+3 −0
Original line number Diff line number Diff line
@@ -308,8 +308,11 @@ static void am79c961_timer(unsigned long data) 
	struct net_device *dev = (struct net_device *)data;

	struct dev_priv *priv = netdev_priv(dev);

	unsigned int lnkstat, carrier;

	unsigned long flags;



	spin_lock_irqsave(&priv->chip_lock, flags);

	lnkstat = read_ireg(dev->base_addr, ISALED0) & ISALED0_LNKST;

	spin_unlock_irqrestore(&priv->chip_lock, flags);

	carrier = netif_carrier_ok(dev);



	if (lnkstat && !carrier) {