diff mbox

[(net.git),1/5] stmmac: fix stmmac_tx_avail should be called with TX locked

Message ID 1415117289-7733-2-git-send-email-peppe.cavallaro@st.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Giuseppe CAVALLARO Nov. 4, 2014, 4:08 p.m. UTC 
From: Fabrice Gasnier <fabrice.gasnier@st.com>

stmmac_tx_avail() may lie if used unprotected. It's using cur_tx
and dirty_tx index. These index may be already in use by tx_clean
when entering xmit routine. So, this should be called locked.

This can cause transmit queue to be stuck, with following message:
NETDEV WATCHDOG: eth0 (stmmaceth): transmit queue 0 timed out

Signed-off-by: Fabrice Gasnier <fabrice.gasnier@st.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_main.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)
diff mbox

Patch

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 6f77a46..bcd8a34 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -1894,7 +1894,10 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 	unsigned int nopaged_len = skb_headlen(skb);
 	unsigned int enh_desc = priv->plat->enh_desc;
 
+	spin_lock(&priv->tx_lock);
+
 	if (unlikely(stmmac_tx_avail(priv) < nfrags + 1)) {
+		spin_unlock(&priv->tx_lock);
 		if (!netif_queue_stopped(dev)) {
 			netif_stop_queue(dev);
 			/* This is a hard error, log it. */
@@ -1903,8 +1906,6 @@  static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 		return NETDEV_TX_BUSY;
 	}
 
-	spin_lock(&priv->tx_lock);
-
 	if (priv->tx_path_in_lpi_mode)
 		stmmac_disable_eee_mode(priv);