[PATCH] natsemi: NAPI and a bugfix

As documented in National application note 1287 the RX state machine on
the natsemi chip can lock up under some conditions (mostly related to
heavy load).  When this happens a series of bogus packets are reported
by the chip including some oversized frames prior to the final lockup.

This patch implements the fix from the application note: when an
oversized packet is reported it resets the RX state machine, dropping
any currently pending packets.

Signed-off-by: Mark Brown <broonie@sirena.org.uk>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
This commit is contained in:
Mark Brown 2006-02-02 00:00:02 +00:00 committed by Jeff Garzik
parent b27a16b7c4
commit e72fd96e8e

View File

@ -1498,6 +1498,31 @@ static void natsemi_reset(struct net_device *dev)
writel(rfcr, ioaddr + RxFilterAddr);
}
static void reset_rx(struct net_device *dev)
{
int i;
struct netdev_private *np = netdev_priv(dev);
void __iomem *ioaddr = ns_ioaddr(dev);
np->intr_status &= ~RxResetDone;
writel(RxReset, ioaddr + ChipCmd);
for (i=0;i<NATSEMI_HW_TIMEOUT;i++) {
np->intr_status |= readl(ioaddr + IntrStatus);
if (np->intr_status & RxResetDone)
break;
udelay(15);
}
if (i==NATSEMI_HW_TIMEOUT) {
printk(KERN_WARNING "%s: RX reset did not complete in %d usec.\n",
dev->name, i*15);
} else if (netif_msg_hw(np)) {
printk(KERN_WARNING "%s: RX reset took %d usec.\n",
dev->name, i*15);
}
}
static void natsemi_reload_eeprom(struct net_device *dev)
{
struct netdev_private *np = netdev_priv(dev);
@ -2292,6 +2317,23 @@ static void netdev_rx(struct net_device *dev, int *work_done, int work_to_do)
"status %#08x.\n", dev->name,
np->cur_rx, desc_status);
np->stats.rx_length_errors++;
/* The RX state machine has probably
* locked up beneath us. Follow the
* reset procedure documented in
* AN-1287. */
spin_lock_irq(&np->lock);
reset_rx(dev);
reinit_rx(dev);
writel(np->ring_dma, ioaddr + RxRingPtr);
check_link(dev);
spin_unlock_irq(&np->lock);
/* We'll enable RX on exit from this
* function. */
break;
} else {
/* There was an error. */
np->stats.rx_errors++;