From e72fd96e8ee3ff4dd80757172a4fe49bd92fea9c Mon Sep 17 00:00:00 2001 From: Mark Brown Date: Thu, 2 Feb 2006 00:00:02 +0000 Subject: [PATCH] [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 Signed-off-by: Jeff Garzik --- drivers/net/natsemi.c | 42 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 42 insertions(+) diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c index e363f9bb35ea..8d4999837b65 100644 --- a/drivers/net/natsemi.c +++ b/drivers/net/natsemi.c @@ -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;iintr_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++;