Bug#656476: Sundance network driver (D-Link DFE-580TX) timeouts rendering interface unusable
Le lundi 30 janvier 2012 à 15:57 +0100, Eric Dumazet a écrit :
> Hmm, TX _completion_ is not run from tasklet but hardware IRQ, this is
> why I added the spin_lock_irqsave().
>
>
> Tasklet fires the TX, but hardware IRQ does the TX completion part.
>
> This driver is ... interesting :)
>
Oh well, we also must make sure we held np->lock in TX completion when
doing our test to eventually call netif_wake_queue(), I missed it was
released too early.
here is a more complete patch.
diff --git a/drivers/net/ethernet/dlink/sundance.c b/drivers/net/ethernet/dlink/sundance.c
index 28a3a9b..d5e9472 100644
--- a/drivers/net/ethernet/dlink/sundance.c
+++ b/drivers/net/ethernet/dlink/sundance.c
@@ -1099,11 +1099,13 @@ start_tx (struct sk_buff *skb, struct net_device *dev)
tasklet_schedule(&np->tx_tasklet);
/* On some architectures: explicitly flush cache lines here. */
- if (np->cur_tx - np->dirty_tx < TX_QUEUE_LEN - 1 &&
- !netif_queue_stopped(dev)) {
- /* do nothing */
- } else {
- netif_stop_queue (dev);
+ if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1) {
+ unsigned long flags;
+
+ spin_lock_irqsave(&np->lock, flags);
+ if (np->cur_tx - np->dirty_tx >= TX_QUEUE_LEN - 1)
+ netif_stop_queue(dev);
+ spin_unlock_irqrestore(&np->lock, flags);
}
if (netif_msg_tx_queued(np)) {
printk (KERN_DEBUG
@@ -1242,8 +1244,8 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
hw_frame_id = ioread8(ioaddr + TxFrameId);
}
+ spin_lock(&np->lock);
if (np->pci_dev->revision >= 0x14) {
- spin_lock(&np->lock);
for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
int entry = np->dirty_tx % TX_RING_SIZE;
struct sk_buff *skb;
@@ -1267,9 +1269,7 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
np->tx_ring[entry].frag[0].addr = 0;
np->tx_ring[entry].frag[0].length = 0;
}
- spin_unlock(&np->lock);
} else {
- spin_lock(&np->lock);
for (; np->cur_tx - np->dirty_tx > 0; np->dirty_tx++) {
int entry = np->dirty_tx % TX_RING_SIZE;
struct sk_buff *skb;
@@ -1286,7 +1286,6 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
np->tx_ring[entry].frag[0].addr = 0;
np->tx_ring[entry].frag[0].length = 0;
}
- spin_unlock(&np->lock);
}
if (netif_queue_stopped(dev) &&
@@ -1294,6 +1293,7 @@ static irqreturn_t intr_handler(int irq, void *dev_instance)
/* The ring is no longer full, clear busy flag. */
netif_wake_queue (dev);
}
+ spin_unlock(&np->lock);
/* Abnormal error summary/uncommon events handlers. */
if (intr_status & (IntrPCIErr | LinkChange | StatsMax))
netdev_error(dev, intr_status);
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