ixgb: add NETIF_F_LLTX analogous to e1000

add NETIF_F_LLTX code like e1000 has

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Auke Kok <auke-jan.h.kok@intel.com>
Signed-off-by: John Ronciak <john.ronciak@intel.com>

1 files changed, 29 insertions, 2 deletions

diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index 13181c4f1d20..466cbe208ef2 100644
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -449,6 +449,9 @@ ixgb_probe(struct pci_dev *pdev,
 #ifdef NETIF_F_TSO
         netdev->features |= NETIF_F_TSO;
 #endif
+#ifdef NETIF_F_LLTX
+        netdev->features |= NETIF_F_LLTX;
+#endif
 
         if(pci_using_dac)
                 netdev->features |= NETIF_F_HIGHDMA;
@@ -1408,13 +1411,26 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
                 return 0;
         }
 
+#ifdef NETIF_F_LLTX
+        local_irq_save(flags);
+        if (!spin_trylock(&adapter->tx_lock)) {
+                /* Collision - tell upper layer to requeue */
+                local_irq_restore(flags);
+                return NETDEV_TX_LOCKED;
+        }
+#else
         spin_lock_irqsave(&adapter->tx_lock, flags);
+#endif
+
         if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED)) {
                 netif_stop_queue(netdev);
                 spin_unlock_irqrestore(&adapter->tx_lock, flags);
-                return 1;
+                return NETDEV_TX_BUSY;
         }
+
+#ifndef NETIF_F_LLTX
         spin_unlock_irqrestore(&adapter->tx_lock, flags);
+#endif
 
         if(adapter->vlgrp && vlan_tx_tag_present(skb)) {
                 tx_flags |= IXGB_TX_FLAGS_VLAN;
@@ -1426,6 +1442,9 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         tso = ixgb_tso(adapter, skb);
         if (tso < 0) {
                 dev_kfree_skb_any(skb);
+#ifdef NETIF_F_LLTX
+                spin_unlock_irqrestore(&adapter->tx_lock, flags);
+#endif
                 return NETDEV_TX_OK;
         }
 
@@ -1439,7 +1458,15 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 
         netdev->trans_start = jiffies;
 
-        return 0;
+#ifdef NETIF_F_LLTX
+        /* Make sure there is space in the ring for the next send. */
+        if(unlikely(IXGB_DESC_UNUSED(&adapter->tx_ring) < DESC_NEEDED))
+                netif_stop_queue(netdev);
+
+        spin_unlock_irqrestore(&adapter->tx_lock, flags);
+
+#endif
+        return NETDEV_TX_OK;
 }
 
 /**