net: ll_temac: Fix bug causing buffer descriptor overrun

As we are actually using a BD for both the skb and each frag contained in
it, the oldest TX BD would be overwritten when there was exactly one BD
less than needed.

Signed-off-by: Esben Haabendal <esben@geanix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 7e42746..6837565 100644 (file)
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -743,7 +743,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
        start_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail;
        cur_p = &lp->tx_bd_v[lp->tx_bd_tail];
 
-       if (temac_check_tx_bd_space(lp, num_frag)) {
+       if (temac_check_tx_bd_space(lp, num_frag + 1)) {
                if (!netif_queue_stopped(ndev))
                        netif_stop_queue(ndev);
                return NETDEV_TX_BUSY;