net: trans_start cleanups

Now that core network takes care of trans_start updates, dont do it
in drivers themselves, if possible. Drivers can avoid one cache miss
(on dev->trans_start) in their start_xmit() handler.

Exceptions are NETIF_F_LLTX drivers

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/3c59x.c b/drivers/net/3c59x.c
index 9752530..dab2afa 100644
--- a/drivers/net/3c59x.c
+++ b/drivers/net/3c59x.c
@@ -1917,7 +1917,7 @@
 
 	/* Issue Tx Enable */
 	iowrite16(TxEnable, ioaddr + EL3_CMD);
-	dev->trans_start = jiffies;
+	dev->trans_start = jiffies; /* prevent tx timeout */
 
 	/* Switch to register set 7 for normal use. */
 	EL3WINDOW(7);
@@ -2063,7 +2063,6 @@
 		}
 	}
 
-	dev->trans_start = jiffies;
 
 	/* Clear the Tx status stack. */
 	{
@@ -2174,7 +2173,6 @@
 	}
 	iowrite16(DownUnstall, ioaddr + EL3_CMD);
 	spin_unlock_irqrestore(&vp->lock, flags);
-	dev->trans_start = jiffies;
 	return NETDEV_TX_OK;
 }