[PATCH net 1/5] dwc_eth_qos: fix race condition in dwceqos_start_xmit

From	Lars Persson <lars.persson@axis.com>
Newsgroups	linux.kernel
Subject	[PATCH net 1/5] dwc_eth_qos: fix race condition in dwceqos_start_xmit
Date	2016-02-29 16:30 +0100
Message-ID	<r7xVL-4Nd-5@gated-at.bofh.it> (permalink)
References	<r7xVL-4Nd-7@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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From: Rabin Vincent <rabinv@axis.com>

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>
---
 drivers/net/ethernet/synopsys/dwc_eth_qos.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/synopsys/dwc_eth_qos.c b/drivers/net/ethernet/synopsys/dwc_eth_qos.c
index fc8bbff..926db2d 100644
--- 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;
-- 
2.1.4

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[PATCH net 1/5] dwc_eth_qos: fix race condition in dwceqos_start_xmit Lars Persson <lars.persson@axis.com> - 2016-02-29 16:30 +0100

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