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authorDmitry Torokhov <dtor@insightbb.com>2006-10-08 00:38:14 -0400
committerJeff Garzik <jeff@garzik.org>2006-12-02 00:11:57 -0500
commitd18e0c4a5434f02586b5fdcbcc72f1fe61ab49e6 (patch)
tree813592f56a6f090c7732aa7da675276b722da6ab
parent5c877fe58c5df19646204b144b978b99c2ef074f (diff)
[PATCH] prism54: fix potential race in reset scheduling
NET: prism54 - fix potential race in reset scheduling There appears to be a race in reset scheduling logic - thread responsible for reseting the interface should clear "reset pending" flag before restarting the queue, otherwise timeout handler might not schedule another reset even if it is needed. This race is mostly theoretical as far as I can see but a race nonetheless. Signed-off-by: Dmitry Torokhov <dtor@mail.ru> Signed-off-by: John W. Linville <linville@tuxdriver.com>
-rw-r--r--drivers/net/wireless/prism54/islpci_eth.c23
1 files changed, 13 insertions, 10 deletions
diff --git a/drivers/net/wireless/prism54/islpci_eth.c b/drivers/net/wireless/prism54/islpci_eth.c
index a8261d8454d..bfbafe99b94 100644
--- a/drivers/net/wireless/prism54/islpci_eth.c
+++ b/drivers/net/wireless/prism54/islpci_eth.c
@@ -253,6 +253,7 @@ islpci_monitor_rx(islpci_private *priv, struct sk_buff **skb)
* header and without the FCS. But there a is a bit that
* indicates if the packet is corrupted :-) */
struct rfmon_header *hdr = (struct rfmon_header *) (*skb)->data;
+
if (hdr->flags & 0x01)
/* This one is bad. Drop it ! */
return -1;
@@ -464,10 +465,8 @@ islpci_eth_receive(islpci_private *priv)
break;
}
/* update the fragment address */
- control_block->rx_data_low[index].address = cpu_to_le32((u32)
- priv->
- pci_map_rx_address
- [index]);
+ control_block->rx_data_low[index].address =
+ cpu_to_le32((u32)priv->pci_map_rx_address[index]);
wmb();
/* increment the driver read pointer */
@@ -484,10 +483,12 @@ islpci_eth_receive(islpci_private *priv)
void
islpci_do_reset_and_wake(void *data)
{
- islpci_private *priv = (islpci_private *) data;
+ islpci_private *priv = data;
+
islpci_reset(priv, 1);
- netif_wake_queue(priv->ndev);
priv->reset_task_pending = 0;
+ smp_wmb();
+ netif_wake_queue(priv->ndev);
}
void
@@ -499,12 +500,14 @@ islpci_eth_tx_timeout(struct net_device *ndev)
/* increment the transmit error counter */
statistics->tx_errors++;
- printk(KERN_WARNING "%s: tx_timeout", ndev->name);
if (!priv->reset_task_pending) {
- priv->reset_task_pending = 1;
- printk(", scheduling a reset");
+ printk(KERN_WARNING
+ "%s: tx_timeout, scheduling reset", ndev->name);
netif_stop_queue(ndev);
+ priv->reset_task_pending = 1;
schedule_work(&priv->reset_task);
+ } else {
+ printk(KERN_WARNING
+ "%s: tx_timeout, waiting for reset", ndev->name);
}
- printk("\n");
}