stmmac: protect tx process with lock (V4)

This patch fixes a problem raised on Orly ARM SMP platform
where, in case of fragmented frames, the descriptors
in the TX ring resulted broken. This was due to a missing lock
protection in the tx process.

Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Tested-by: Srinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 9 insertions, 0 deletions

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 1434bdb390d..50e95d87857 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -70,6 +70,7 @@ struct stmmac_priv {
 
         u32 msg_enable;
         spinlock_t lock;
+        spinlock_t tx_lock;
         int wolopts;
         int wolenabled;
         int wol_irq;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index ae5debb1f5c..f80190d78f9 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -588,6 +588,8 @@ static void stmmac_tx(struct stmmac_priv *priv)
 {
         unsigned int txsize = priv->dma_tx_size;
 
+        spin_lock(&priv->tx_lock);
+
         while (priv->dirty_tx != priv->cur_tx) {
                 int last;
                 unsigned int entry = priv->dirty_tx % txsize;
@@ -651,6 +653,7 @@ static void stmmac_tx(struct stmmac_priv *priv)
                 }
                 netif_tx_unlock(priv->dev);
         }
+        spin_unlock(&priv->tx_lock);
 }
 
 static inline void stmmac_enable_irq(struct stmmac_priv *priv)
@@ -1078,6 +1081,8 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
                 return NETDEV_TX_BUSY;
         }
 
+        spin_lock(&priv->tx_lock);
+
         entry = priv->cur_tx % txsize;
 
 #ifdef STMMAC_XMIT_DEBUG
@@ -1166,6 +1171,8 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
         priv->hw->dma->enable_dma_transmission(priv->ioaddr);
 
+        spin_unlock(&priv->tx_lock);
+
         return NETDEV_TX_OK;
 }
 
@@ -1731,6 +1738,7 @@ static int stmmac_probe(struct net_device *dev)
                         "please, use ifconfig or nwhwconfig!\n");
 
         spin_lock_init(&priv->lock);
+        spin_lock_init(&priv->tx_lock);
 
         ret = register_netdev(dev);
         if (ret) {