From 53044718e1955c3f241fdaa8c3153e280f4dab2d Mon Sep 17 00:00:00 2001 From: Felix Fietkau Date: Fri, 7 Dec 2007 00:03:06 +0000 Subject: [PATCH] [PATCH 1/2] Fix race between device reset and start_xmit Signed-off-by: oliver@opencloud.com SVN-Revision: 9664 --- target/linux/ar7/files/drivers/net/cpmac.c | 93 ++++++++++++++-------- 1 file changed, 61 insertions(+), 32 deletions(-) diff --git a/target/linux/ar7/files/drivers/net/cpmac.c b/target/linux/ar7/files/drivers/net/cpmac.c index 2c8d52963b..45bd1eeb8e 100644 --- a/target/linux/ar7/files/drivers/net/cpmac.c +++ b/target/linux/ar7/files/drivers/net/cpmac.c @@ -37,6 +37,7 @@ #include #include #include +#include MODULE_AUTHOR("Eugene Konev "); MODULE_DESCRIPTION("TI AR7 ethernet driver (CPMAC)"); @@ -211,6 +212,7 @@ struct cpmac_priv { struct net_device *dev; struct work_struct reset_work; struct platform_device *pdev; + atomic_t reset_pending; }; static irqreturn_t cpmac_irq(int, void *); @@ -460,6 +462,9 @@ static int cpmac_start_xmit(struct sk_buff *skb, struct net_device *dev) struct cpmac_desc *desc; struct cpmac_priv *priv = netdev_priv(dev); + if (unlikely(atomic_read(&priv->reset_pending))) + return NETDEV_TX_BUSY; + if (unlikely(skb_padto(skb, ETH_ZLEN))) return NETDEV_TX_OK; @@ -639,14 +644,14 @@ static void cpmac_clear_tx(struct net_device *dev) priv->desc_ring[i].dataflags = 0; if (priv->desc_ring[i].skb) { dev_kfree_skb_any(priv->desc_ring[i].skb); - if (netif_subqueue_stopped(dev, i)) - netif_wake_subqueue(dev, i); + priv->desc_ring[i].skb = NULL; } } } static void cpmac_hw_error(struct work_struct *work) { + int i; struct cpmac_priv *priv = container_of(work, struct cpmac_priv, reset_work); @@ -655,7 +660,45 @@ static void cpmac_hw_error(struct work_struct *work) spin_unlock(&priv->rx_lock); cpmac_clear_tx(priv->dev); cpmac_hw_start(priv->dev); - netif_start_queue(priv->dev); + barrier(); + atomic_dec(&priv->reset_pending); + + for (i = 0; i < CPMAC_QUEUES; i++) { + netif_wake_subqueue(priv->dev, i); + } + netif_wake_queue(priv->dev); +} + +static void cpmac_check_status(struct net_device *dev) +{ + struct cpmac_priv *priv = netdev_priv(dev); + + u32 macstatus = cpmac_read(priv->regs, CPMAC_MAC_STATUS); + int rx_channel = (macstatus >> 8) & 7; + int rx_code = (macstatus >> 12) & 15; + int tx_channel = (macstatus >> 16) & 7; + int tx_code = (macstatus >> 20) & 15; + + if (rx_code || tx_code) { + if (netif_msg_drv(priv) && net_ratelimit()) { + /* Can't find any documentation on what these error codes actually are. + * So just log them and hope.. + */ + if (rx_code) + printk(KERN_WARNING "%s: host error %d on rx channel %d (macstatus %08x), resetting\n", + dev->name, rx_code, rx_channel, macstatus); + if (tx_code) + printk(KERN_WARNING "%s: host error %d on tx channel %d (macstatus %08x), resetting\n", + dev->name, tx_code, tx_channel, macstatus); + } + + netif_stop_queue(dev); + cpmac_hw_stop(dev); + if (schedule_work(&priv->reset_work)) + atomic_inc(&priv->reset_pending); + if (unlikely(netif_msg_hw(priv))) + cpmac_dump_regs(dev); + } } static irqreturn_t cpmac_irq(int irq, void *dev_id) @@ -687,48 +730,33 @@ static irqreturn_t cpmac_irq(int irq, void *dev_id) cpmac_write(priv->regs, CPMAC_MAC_EOI_VECTOR, 0); - if (unlikely(status & (MAC_INT_HOST | MAC_INT_STATUS))) { - if (netif_msg_drv(priv) && net_ratelimit()) - printk(KERN_ERR "%s: hw error, resetting...\n", - dev->name); - netif_stop_queue(dev); - cpmac_hw_stop(dev); - schedule_work(&priv->reset_work); - if (unlikely(netif_msg_hw(priv))) - cpmac_dump_regs(dev); - } + if (unlikely(status & (MAC_INT_HOST | MAC_INT_STATUS))) + cpmac_check_status(dev); return IRQ_HANDLED; } static void cpmac_tx_timeout(struct net_device *dev) { - struct cpmac_priv *priv = netdev_priv(dev); int i; + struct cpmac_priv *priv = netdev_priv(dev); spin_lock(&priv->lock); dev->stats.tx_errors++; spin_unlock(&priv->lock); if (netif_msg_tx_err(priv) && net_ratelimit()) printk(KERN_WARNING "%s: transmit timeout\n", dev->name); - /* - * FIXME: waking up random queue is not the best thing to - * do... on the other hand why we got here at all? - */ -#ifdef CONFIG_NETDEVICES_MULTIQUEUE - for (i = 0; i < CPMAC_QUEUES; i++) - if (priv->desc_ring[i].skb) { - priv->desc_ring[i].dataflags = 0; - dev_kfree_skb_any(priv->desc_ring[i].skb); - netif_wake_subqueue(dev, i); - break; - } -#else - priv->desc_ring[0].dataflags = 0; - if (priv->desc_ring[0].skb) - dev_kfree_skb_any(priv->desc_ring[0].skb); - netif_wake_queue(dev); -#endif + + atomic_inc(&priv->reset_pending); + barrier(); + cpmac_clear_tx(dev); + barrier(); + atomic_dec(&priv->reset_pending); + + netif_wake_queue(priv->dev); + for (i = 0; i < CPMAC_QUEUES; i++) { + netif_wake_subqueue(dev, i); + } } static int cpmac_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd) @@ -924,6 +952,7 @@ static int cpmac_open(struct net_device *dev) goto fail_irq; } + atomic_set(&priv->reset_pending, 0); INIT_WORK(&priv->reset_work, cpmac_hw_error); cpmac_hw_start(dev); -- 2.30.2