qlge: Fix TX queue stoppage due to full condition.

TX queue was being stopped at beginning of send path instead
of at the end when last descriptor is used.

Signed-off-by: Jitendra Kalsaria <jitendra.kalsaria@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/qlogic/qlge/qlge_main.c b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
index ca427eb323690b486262fb5b5f5c2ae14c095b69..fb86f06e8f1e85f7ed08e024b82779eab903a356 100644 (file)
--- a/drivers/net/ethernet/qlogic/qlge/qlge_main.c
+++ b/drivers/net/ethernet/qlogic/qlge/qlge_main.c
@@ -2556,7 +2556,7 @@ static netdev_tx_t qlge_send(struct sk_buff *skb, struct net_device *ndev)
 
        if (unlikely(atomic_read(&tx_ring->tx_count) < 2)) {
                netif_info(qdev, tx_queued, qdev->ndev,
-                          "%s: shutting down tx queue %d du to lack of resources.\n",
+                          "%s: BUG! shutting down tx queue %d due to lack of resources.\n",
                           __func__, tx_ring_idx);
                netif_stop_subqueue(ndev, tx_ring->wq_id);
                atomic_inc(&tx_ring->queue_stopped);
@@ -2610,6 +2610,16 @@ static netdev_tx_t qlge_send(struct sk_buff *skb, struct net_device *ndev)
                     tx_ring->prod_idx, skb->len);
 
        atomic_dec(&tx_ring->tx_count);
+
+       if (unlikely(atomic_read(&tx_ring->tx_count) < 2)) {
+               netif_stop_subqueue(ndev, tx_ring->wq_id);
+               if ((atomic_read(&tx_ring->tx_count) > (tx_ring->wq_len / 4)))
+                       /*
+                        * The queue got stopped because the tx_ring was full.
+                        * Wake it up, because it's now at least 25% empty.
+                        */
+                       netif_wake_subqueue(qdev->ndev, tx_ring->wq_id);
+       }
        return NETDEV_TX_OK;
 }