From d18e0c4a5434f02586b5fdcbcc72f1fe61ab49e6 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Sun, 8 Oct 2006 00:38:14 -0400 Subject: [PATCH] [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 Signed-off-by: John W. Linville --- drivers/net/wireless/prism54/islpci_eth.c | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) diff --git a/drivers/net/wireless/prism54/islpci_eth.c b/drivers/net/wireless/prism54/islpci_eth.c index a8261d8454dd..bfbafe99b94a 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"); }