ixgb: remove lltx support and update tx routine

a) kernel developers suggest LLTX is broken and unsafe to use, remove it.
b) remember to pre-stop the queue if we won't have room
c) removing lltx means we can remove our tx lock

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

diff --git a/drivers/net/ixgb/ixgb.h b/drivers/net/ixgb/ixgb.h
index 16f9c75..3cec7b9 100644 (file)
--- a/drivers/net/ixgb/ixgb.h
+++ b/drivers/net/ixgb/ixgb.h
@@ -157,7 +157,6 @@ struct ixgb_adapter {
        u32 part_num;
        u16 link_speed;
        u16 link_duplex;
-       spinlock_t tx_lock;
        struct work_struct tx_timeout_task;
 
        struct timer_list blink_timer;

diff --git a/drivers/net/ixgb/ixgb_main.c b/drivers/net/ixgb/ixgb_main.c
index 79082eb..bd08e19 100644 (file)
--- a/drivers/net/ixgb/ixgb_main.c
+++ b/drivers/net/ixgb/ixgb_main.c
@@ -448,9 +448,6 @@ ixgb_probe(struct pci_dev *pdev,
                           NETIF_F_HW_VLAN_RX |
                           NETIF_F_HW_VLAN_FILTER;
        netdev->features |= NETIF_F_TSO;
-#ifdef NETIF_F_LLTX
-       netdev->features |= NETIF_F_LLTX;
-#endif
 
        if(pci_using_dac)
                netdev->features |= NETIF_F_HIGHDMA;
@@ -577,8 +574,6 @@ ixgb_sw_init(struct ixgb_adapter *adapter)
        /* enable flow control to be programmed */
        hw->fc.send_xon = 1;
 
-       spin_lock_init(&adapter->tx_lock);
-
        set_bit(__IXGB_DOWN, &adapter->flags);
        return 0;
 }
@@ -1441,7 +1436,6 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
        struct ixgb_adapter *adapter = netdev_priv(netdev);
        unsigned int first;
        unsigned int tx_flags = 0;
-       unsigned long flags;
        int vlan_id = 0;
        int tso;
 
@@ -1455,26 +1449,9 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
                return 0;
        }
 
-#ifdef NETIF_F_LLTX
-       if (!spin_trylock_irqsave(&adapter->tx_lock, flags)) {
-               /* 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_maybe_stop_tx(netdev, &adapter->tx_ring,
-                     DESC_NEEDED))) {
-               netif_stop_queue(netdev);
-               spin_unlock_irqrestore(&adapter->tx_lock, flags);
+                     DESC_NEEDED)))
                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;
@@ -1486,9 +1463,6 @@ 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;
        }
 
@@ -1502,13 +1476,9 @@ ixgb_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 
        netdev->trans_start = jiffies;
 
-#ifdef NETIF_F_LLTX
        /* Make sure there is space in the ring for the next send. */
        ixgb_maybe_stop_tx(netdev, &adapter->tx_ring, DESC_NEEDED);
 
-       spin_unlock_irqrestore(&adapter->tx_lock, flags);
-
-#endif
        return NETDEV_TX_OK;
 }