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Fix race between device reset and start_xmit

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Signed-off-by: oliver@opencloud.com

SVN-Revision: 9664
This commit is contained in:
Felix Fietkau 2007-12-07 00:03:06 +00:00
parent f45990d8fe
commit 6111ac6f94
1 changed files with 61 additions and 32 deletions
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93
target/linux/ar7/files/drivers/net/cpmac.c
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@ -37,6 +37,7 @@
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <asm/gpio.h>
#include <asm/atomic.h>
MODULE_AUTHOR("Eugene Konev <ejka@imfi.kspu.ru>");
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);