[PATCH] (17/23) sk98: use lockless transmit

[Stephen Hemminger <shemminger@xxxxxxxx>]

This driver lends it self to the new lockless transmit hook in 2.6.
Also, flag that driver can do 64 bit DMA, if it is successful in
setting the bigger mask.

Signed-off-by: Stephen Hemminger <shemminger@xxxxxxxx>

diff -Nru a/drivers/net/sk98lin/skge.c b/drivers/net/sk98lin/skge.c
--- a/drivers/net/sk98lin/skge.c        2004-11-03 18:57:15 -08:00
+++ b/drivers/net/sk98lin/skge.c        2004-11-03 18:57:15 -08:00
@@ -323,6 +323,7 @@
        DEV_NET                 *pNet = NULL;
        struct net_device       *dev = NULL;
        static int boards_found = 0;
+       int pci_using_dac  = 0;
        int error = -ENODEV;
 
        error = pci_enable_device(pdev);
@@ -332,8 +333,9 @@
        }
  
        /* Configure DMA attributes. */
-       if ((error = pci_set_dma_mask(pdev, (u64) 0xffffffffffffffffULL)) ||
-           (error = pci_set_dma_mask(pdev, (u64) 0xffffffff))) {
+       if (!(error = pci_set_dma_mask(pdev, DMA_64BIT_MASK))) 
+               pci_using_dac = 1;
+       else if ((error = pci_set_dma_mask(pdev, DMA_32BIT_MASK))) {
                printk(KERN_ERR "sk98lin: cannot set PCI dma mask\n");
                goto out_disable_device;
        }
@@ -375,6 +377,8 @@
        }
 
        SkGeDevInit(dev, pdev);
+       if (pci_using_dac)
+               dev->features |= NETIF_F_HIGHDMA;
 
        pAC->Index = boards_found++;
 
@@ -438,6 +442,9 @@
 
                SkGeDevInit(dev, pdev);
 
+               if (pci_using_dac)
+                       dev->features |= NETIF_F_HIGHDMA;
+
 #ifdef SK_ZEROCOPY
 #ifdef USE_SK_TX_CHECKSUM
                if (pAC->ChipsetType)
@@ -447,7 +454,6 @@
 #endif
 #endif
 
-
                if (register_netdev(dev)) {
                        printk(KERN_ERR "SKGE: Could not register device.\n");
                        free_netdev(dev);
@@ -501,9 +507,10 @@
 #endif
        SET_ETHTOOL_OPS(dev, &SkGeEthtoolOps);
        SET_NETDEV_DEV(dev, &pdev->dev);
-}
-
 
+       dev->flags &= ~IFF_RUNNING;
+       dev->features |= NETIF_F_LLTX;
+}
 /*****************************************************************************
  *
  *     SkGeInitPCI - Init the PCI resources
@@ -1707,7 +1714,13 @@
        else
                pTxPort = &pAC->TxPort[pAC->ActivePort][TX_PRIO_LOW];
 
-       spin_lock_irqsave(&pTxPort->TxDesRingLock, flags);
+       local_irq_save(flags); 
+       if (!spin_trylock(&pTxPort->TxDesRingLock)) {
+               /* Collision - tell upper layer to requeue */ 
+               local_irq_restore(flags); 
+               return NETDEV_TX_LOCKED; 
+       } 
+
        if ((!skb_shinfo(skb)->nr_frags) ||
                (pAC->GIni.GIChipId == CHIP_ID_GENESIS)) {
                /* Don't activate scatter-gather and hardware checksum */