dwc_eth_qos: fix race condition in dwceqos_start_xmit

The xmit handler and the tx_reclaim tasklet had a race on the tx_free
variable which could lead to a tx timeout if tx_free was updated after
the tx complete interrupt.

Signed-off-by: Rabin Vincent <rabinv@axis.com>
Signed-off-by: Lars Persson <larper@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/synopsys/dwc_eth_qos.c b/drivers/net/ethernet/synopsys/dwc_eth_qos.c
index fc8bbff..926db2d 100644 (file)
--- a/drivers/net/ethernet/synopsys/dwc_eth_qos.c
+++ b/drivers/net/ethernet/synopsys/dwc_eth_qos.c
@@ -2178,12 +2178,10 @@ static int dwceqos_start_xmit(struct sk_buff *skb, struct net_device *ndev)
                ((trans.initial_descriptor + trans.nr_descriptors) %
                 DWCEQOS_TX_DCNT));
 
-       dwceqos_tx_finalize(skb, lp, &trans);
-
-       netdev_sent_queue(ndev, skb->len);
-
        spin_lock_bh(&lp->tx_lock);
        lp->tx_free -= trans.nr_descriptors;
+       dwceqos_tx_finalize(skb, lp, &trans);
+       netdev_sent_queue(ndev, skb->len);
        spin_unlock_bh(&lp->tx_lock);
 
        ndev->trans_start = jiffies;