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Commit 61dbcece authored by Benjamin Herrenschmidt's avatar Benjamin Herrenschmidt Committed by Jeff Garzik
Browse files

ibm_newemac: Fix possible lockup on close 



It's a bad idea to call flush_scheduled_work from within a
netdev->stop because the linkwatch will occasionally take the
rtnl lock from a workqueue context, and thus that can deadlock.

This reworks things a bit in that area to avoid the problem.

Signed-off-by: default avatarBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: default avatarJeff Garzik <jeff@garzik.org>
parent 2ffbb837

drivers/net/ibm_newemac/core.c

+20 −11
Original line number Diff line number Diff line
@@ -642,9 +642,11 @@ static void emac_reset_work(struct work_struct *work) 
	DBG(dev, "reset_work" NL);



	mutex_lock(&dev->link_lock);

	if (dev->opened) {

		emac_netif_stop(dev);

		emac_full_tx_reset(dev);

		emac_netif_start(dev);

	}

	mutex_unlock(&dev->link_lock);

}
@@ -1063,10 +1065,9 @@ static int emac_open(struct net_device *ndev) 
	dev->rx_sg_skb = NULL;



	mutex_lock(&dev->link_lock);

	dev->opened = 1;



	/* XXX Start PHY polling now. Shouldn't wr do like sungem instead and

	 * always poll the PHY even when the iface is down ? That would allow

	 * things like laptop-net to work. --BenH

	/* Start PHY polling now.

	 */

	if (dev->phy.address >= 0) {

		int link_poll_interval;
@@ -1145,9 +1146,11 @@ static void emac_link_timer(struct work_struct *work) 
	int link_poll_interval;



	mutex_lock(&dev->link_lock);



	DBG2(dev, "link timer" NL);



	if (!dev->opened)

		goto bail;



	if (dev->phy.def->ops->poll_link(&dev->phy)) {

		if (!netif_carrier_ok(dev->ndev)) {

			/* Get new link parameters */
@@ -1170,13 +1173,14 @@ static void emac_link_timer(struct work_struct *work) 
		link_poll_interval = PHY_POLL_LINK_OFF;

	}

	schedule_delayed_work(&dev->link_work, link_poll_interval);



 bail:

	mutex_unlock(&dev->link_lock);

}



static void emac_force_link_update(struct emac_instance *dev)

{

	netif_carrier_off(dev->ndev);

	smp_rmb();

	if (dev->link_polling) {

		cancel_rearming_delayed_work(&dev->link_work);

		if (dev->link_polling)
@@ -1191,11 +1195,14 @@ static int emac_close(struct net_device *ndev) 


	DBG(dev, "close" NL);



	if (dev->phy.address >= 0)

	if (dev->phy.address >= 0) {

		dev->link_polling = 0;

		cancel_rearming_delayed_work(&dev->link_work);



	}

	mutex_lock(&dev->link_lock);

	emac_netif_stop(dev);

	flush_scheduled_work();

	dev->opened = 0;

	mutex_unlock(&dev->link_lock);



	emac_rx_disable(dev);

	emac_tx_disable(dev);
@@ -2756,6 +2763,8 @@ static int __devexit emac_remove(struct of_device *ofdev) 


	unregister_netdev(dev->ndev);



	flush_scheduled_work();



	if (emac_has_feature(dev, EMAC_FTR_HAS_TAH))

		tah_detach(dev->tah_dev, dev->tah_port);

	if (emac_has_feature(dev, EMAC_FTR_HAS_RGMII))

drivers/net/ibm_newemac/core.h

+1 −0
Original line number Diff line number Diff line
@@ -258,6 +258,7 @@ struct emac_instance { 
	int				stop_timeout;	/* in us */

	int				no_mcast;

	int				mcast_pending;

	int				opened;

	struct work_struct		reset_work;

	spinlock_t			lock;

};