diff -Nurp linux-2.6.37-001-bsa400/drivers/net//macb.c
linux-2.6.37-macb-hsr/drivers/net//macb.c
--- linux-2.6.37-orig/drivers/net//macb.c	2012-09-16 22:41:02.746754672 +0200
+++ linux-2.6.37-macb/drivers/net//macb.c	2012-09-17 00:34:35.161389720 +0200
@@ -376,8 +379,9 @@ static void macb_tx(struct macb *bp)

 			rmb();

-			dma_unmap_single(&bp->pdev->dev, rp->mapping, skb->len,
-							 DMA_TO_DEVICE);
+			dma_unmap_single(&bp->pdev->dev, rp->mapping,
+					 max(skb->len, (unsigned int) ETH_ZLEN),
+					 DMA_TO_DEVICE);
 			rp->skb = NULL;
 			dev_kfree_skb_irq(skb);
 		}
@@ -413,7 +417,8 @@ static void macb_tx(struct macb *bp)

 		dev_dbg(&bp->pdev->dev, "skb %u (data %p) TX complete\n",
 			tail, skb->data);
-		dma_unmap_single(&bp->pdev->dev, rp->mapping, skb->len,
+		dma_unmap_single(&bp->pdev->dev, rp->mapping,
+				 max(skb->len, (unsigned int) ETH_ZLEN),
 				 DMA_TO_DEVICE);
 		bp->stats.tx_packets++;
 		bp->stats.tx_bytes += skb->len;
@@ -675,7 +680,10 @@ static int macb_start_xmit(struct sk_buf
 	printk("\n");
 #endif

-	len = skb->len;
+	if (skb_padto(skb, ETH_ZLEN) != 0)
+		return NETDEV_TX_OK; /* There is no NETDEV_TX_FAIL... */
+
+	len = max(skb->len, (unsigned int) ETH_ZLEN);
 	spin_lock_irqsave(&bp->lock, flags);

 	/* This is a hard error, log it. */