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: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Benjamin Herrenschmidt 2007-11-20 14:50:46 +11:00 committed by Jeff Garzik
parent 2ffbb8377c
commit 61dbcecef5
2 changed files with 21 additions and 11 deletions

View File

@ -642,9 +642,11 @@ static void emac_reset_work(struct work_struct *work)
DBG(dev, "reset_work" NL);
mutex_lock(&dev->link_lock);
emac_netif_stop(dev);
emac_full_tx_reset(dev);
emac_netif_start(dev);
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))

View File

@ -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;
};