net: remove LLTX in atl2 driver

When NETIF_F_LLTX is set, the atlx driver will use a private lock.
But in recent kernels this implementation seems redundant and
can cause problems where AF_PACKET sees things twice. Since
NETIF_F_LLTX is marked as deprecated and shouldn't be used in
new driver, this patch removes NETIF_F_LLTX and adds a mmiowb
before sending packet. I have tested this driver on a Eee PC.
It works well.

Signed-off-by: Kevin Hao <kexin.hao@windriver.com>
Acked-by: Jay Cliburn <jacliburn@bellsouth.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 1 insertions, 24 deletions

diff --git a/drivers/net/atlx/atl2.c b/drivers/net/atlx/atl2.c
index 4f82f666153..f5bdc92c1a6 100644
--- a/drivers/net/atlx/atl2.c
+++ b/drivers/net/atlx/atl2.c
@@ -116,7 +116,6 @@ static int __devinit atl2_sw_init(struct atl2_adapter *adapter)
         hw->max_frame_size = adapter->netdev->mtu;
 
         spin_lock_init(&adapter->stats_lock);
-        spin_lock_init(&adapter->tx_lock);
 
         set_bit(__ATL2_DOWN, &adapter->flags);
 
@@ -751,11 +750,7 @@ static void atl2_down(struct atl2_adapter *adapter)
          * reschedule our watchdog timer */
         set_bit(__ATL2_DOWN, &adapter->flags);
 
-#ifdef NETIF_F_LLTX
-        netif_stop_queue(netdev);
-#else
         netif_tx_disable(netdev);
-#endif
 
         /* reset MAC to disable all RX/TX */
         atl2_reset_hw(&adapter->hw);
@@ -831,7 +826,6 @@ static inline int TxdFreeBytes(struct atl2_adapter *adapter)
 static int atl2_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
 {
         struct atl2_adapter *adapter = netdev_priv(netdev);
-        unsigned long flags;
         struct tx_pkt_header *txph;
         u32 offset, copy_len;
         int txs_unused;
@@ -847,16 +841,6 @@ static int atl2_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
                 return NETDEV_TX_OK;
         }
 
-#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
         txs_unused = TxsFreeUnit(adapter);
         txbuf_unused = TxdFreeBytes(adapter);
 
@@ -864,7 +848,6 @@ static int atl2_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
                 txs_unused < 1) {
                 /* not enough resources */
                 netif_stop_queue(netdev);
-                spin_unlock_irqrestore(&adapter->tx_lock, flags);
                 return NETDEV_TX_BUSY;
         }
 
@@ -910,8 +893,7 @@ static int atl2_xmit_frame(struct sk_buff *skb, struct net_device *netdev)
         ATL2_WRITE_REGW(&adapter->hw, REG_MB_TXD_WR_IDX,
                 (adapter->txd_write_ptr >> 2));
 
-        spin_unlock_irqrestore(&adapter->tx_lock, flags);
-
+        mmiowb();
         netdev->trans_start = jiffies;
         dev_kfree_skb_any(skb);
         return NETDEV_TX_OK;
@@ -1449,10 +1431,6 @@ static int __devinit atl2_probe(struct pci_dev *pdev,
         netdev->features |= (NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX);
 #endif
 
-#ifdef NETIF_F_LLTX
-        netdev->features |= NETIF_F_LLTX;
-#endif
-
         /* Init PHY as early as possible due to power saving issue  */
         atl2_phy_init(&adapter->hw);
 
diff --git a/drivers/net/atlx/atl2.h b/drivers/net/atlx/atl2.h
index 6e1f28ff227..09974df76b1 100644
--- a/drivers/net/atlx/atl2.h
+++ b/drivers/net/atlx/atl2.h
@@ -462,7 +462,6 @@ struct atl2_adapter {
         u16 link_duplex;
 
         spinlock_t stats_lock;
-        spinlock_t tx_lock;
 
         struct work_struct reset_task;
         struct work_struct link_chg_task;