From 14fdd90ef2ec1878d6851ec4dd8d5abb2cef098c Mon Sep 17 00:00:00 2001 From: "broonie@sirena.org.uk" Date: Wed, 14 Mar 2007 19:49:13 +0000 Subject: natsemi: Consistently use interrupt enable/disable functions The natsemi drivers include functions for enabling and disabling interrupts from the chip but these are not used in all code paths. This patch changes the code paths that touch the interrupt enable register to use the functions. In all cases this adds an extra PCI read to post the operation but since none of these are in fast paths this shouldn't be too much of a problem. Signed-Off-By: Mark Brown Signed-off-by: Jeff Garzik --- drivers/net/natsemi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/net/natsemi.c') diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c index c6172a77a6d7..2888880df3b7 100644 --- a/drivers/net/natsemi.c +++ b/drivers/net/natsemi.c @@ -1712,7 +1712,7 @@ static void init_registers(struct net_device *dev) /* Enable interrupts by setting the interrupt mask. */ writel(DEFAULT_INTR, ioaddr + IntrMask); - writel(1, ioaddr + IntrEnable); + natsemi_irq_enable(dev); writel(RxOn | TxOn, ioaddr + ChipCmd); writel(StatsClear, ioaddr + StatsCtrl); /* Clear Stats */ @@ -3071,7 +3071,7 @@ static void enable_wol_mode(struct net_device *dev, int enable_intr) * Could be used to send a netlink message. */ writel(WOLPkt | LinkChange, ioaddr + IntrMask); - writel(1, ioaddr + IntrEnable); + natsemi_irq_enable(dev); } } @@ -3202,7 +3202,7 @@ static int natsemi_suspend (struct pci_dev *pdev, pm_message_t state) disable_irq(dev->irq); spin_lock_irq(&np->lock); - writel(0, ioaddr + IntrEnable); + natsemi_irq_disable(dev); np->hands_off = 1; natsemi_stop_rxtx(dev); netif_stop_queue(dev); -- cgit v1.2.2 From 069f8256362b7a17da532f0631cee73b4cfee65b Mon Sep 17 00:00:00 2001 From: "broonie@sirena.org.uk" Date: Wed, 14 Mar 2007 19:49:14 +0000 Subject: natsemi: Fix NAPI for interrupt sharing The interrupt status register for the natsemi chips is clear on read and was read unconditionally from both the interrupt and from the NAPI poll routine, meaning that if the interrupt service routine was called (for example, due to a shared interrupt) while a NAPI poll was scheduled interrupts could be missed. This patch fixes that by ensuring that the interrupt status register is only read by the interrupt handler when interrupts are enabled from the chip. It also reverts a workaround for this problem from the netpoll hook and improves the trace for interrupt events. Thanks to Sergei Shtylyov for spotting the issue, Mark Huth for a simpler method and Simon Blake for testing resources. Signed-Off-By: Mark Brown Signed-off-by: Jeff Garzik --- drivers/net/natsemi.c | 38 ++++++++++++++++++++------------------ 1 file changed, 20 insertions(+), 18 deletions(-) (limited to 'drivers/net/natsemi.c') diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c index 2888880df3b7..5f88200724e6 100644 --- a/drivers/net/natsemi.c +++ b/drivers/net/natsemi.c @@ -2119,28 +2119,35 @@ static irqreturn_t intr_handler(int irq, void *dev_instance) struct netdev_private *np = netdev_priv(dev); void __iomem * ioaddr = ns_ioaddr(dev); - if (np->hands_off) + /* Reading IntrStatus automatically acknowledges so don't do + * that while interrupts are disabled, (for example, while a + * poll is scheduled). */ + if (np->hands_off || !readl(ioaddr + IntrEnable)) return IRQ_NONE; - /* Reading automatically acknowledges. */ np->intr_status = readl(ioaddr + IntrStatus); + if (!np->intr_status) + return IRQ_NONE; + if (netif_msg_intr(np)) printk(KERN_DEBUG "%s: Interrupt, status %#08x, mask %#08x.\n", dev->name, np->intr_status, readl(ioaddr + IntrMask)); - if (!np->intr_status) - return IRQ_NONE; - prefetch(&np->rx_skbuff[np->cur_rx % RX_RING_SIZE]); if (netif_rx_schedule_prep(dev)) { /* Disable interrupts and register for poll */ natsemi_irq_disable(dev); __netif_rx_schedule(dev); - } + } else + printk(KERN_WARNING + "%s: Ignoring interrupt, status %#08x, mask %#08x.\n", + dev->name, np->intr_status, + readl(ioaddr + IntrMask)); + return IRQ_HANDLED; } @@ -2156,6 +2163,12 @@ static int natsemi_poll(struct net_device *dev, int *budget) int work_done = 0; do { + if (netif_msg_intr(np)) + printk(KERN_DEBUG + "%s: Poll, status %#08x, mask %#08x.\n", + dev->name, np->intr_status, + readl(ioaddr + IntrMask)); + if (np->intr_status & (IntrTxDone | IntrTxIntr | IntrTxIdle | IntrTxErr)) { spin_lock(&np->lock); @@ -2399,19 +2412,8 @@ static struct net_device_stats *get_stats(struct net_device *dev) #ifdef CONFIG_NET_POLL_CONTROLLER static void natsemi_poll_controller(struct net_device *dev) { - struct netdev_private *np = netdev_priv(dev); - disable_irq(dev->irq); - - /* - * A real interrupt might have already reached us at this point - * but NAPI might still haven't called us back. As the interrupt - * status register is cleared by reading, we should prevent an - * interrupt loss in this case... - */ - if (!np->intr_status) - intr_handler(dev->irq, dev); - + intr_handler(dev->irq, dev); enable_irq(dev->irq); } #endif -- cgit v1.2.2 From d2a900365b8963d7ca46f05d8e7176d1be3cc71d Mon Sep 17 00:00:00 2001 From: "broonie@sirena.org.uk" Date: Wed, 14 Mar 2007 19:49:15 +0000 Subject: natsemi: Avoid IntrStatus lossage if RX state machine resets. This patch fixes the poll routine for the natsemi driver so that if the driver detects an RX state machine lockup then no interrupts will be lost while the driver recovers from that. Signed-Off-By: Mark Brown Signed-off-by: Jeff Garzik --- drivers/net/natsemi.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) (limited to 'drivers/net/natsemi.c') diff --git a/drivers/net/natsemi.c b/drivers/net/natsemi.c index 5f88200724e6..349b96a3ec4c 100644 --- a/drivers/net/natsemi.c +++ b/drivers/net/natsemi.c @@ -2169,6 +2169,14 @@ static int natsemi_poll(struct net_device *dev, int *budget) dev->name, np->intr_status, readl(ioaddr + IntrMask)); + /* netdev_rx() may read IntrStatus again if the RX state + * machine falls over so do it first. */ + if (np->intr_status & + (IntrRxDone | IntrRxIntr | RxStatusFIFOOver | + IntrRxErr | IntrRxOverrun)) { + netdev_rx(dev, &work_done, work_to_do); + } + if (np->intr_status & (IntrTxDone | IntrTxIntr | IntrTxIdle | IntrTxErr)) { spin_lock(&np->lock); @@ -2180,12 +2188,6 @@ static int natsemi_poll(struct net_device *dev, int *budget) if (np->intr_status & IntrAbnormalSummary) netdev_error(dev, np->intr_status); - if (np->intr_status & - (IntrRxDone | IntrRxIntr | RxStatusFIFOOver | - IntrRxErr | IntrRxOverrun)) { - netdev_rx(dev, &work_done, work_to_do); - } - *budget -= work_done; dev->quota -= work_done; -- cgit v1.2.2