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/eth16i.c b/drivers/net/eth16i.c
index d4e24f0..874973f 100644
--- a/drivers/net/eth16i.c
+++ b/drivers/net/eth16i.c
@@ -1027,7 +1027,7 @@
 	inw(ioaddr + TX_STATUS_REG),  (inb(ioaddr + TX_STATUS_REG) & TX_DONE) ?
 		       "IRQ conflict" : "network cable problem");
 
-	dev->trans_start = jiffies;
+	dev->trans_start = jiffies; /* prevent tx timeout */
 
 	/* Let's dump all registers */
 	if(eth16i_debug > 0) {
@@ -1047,7 +1047,7 @@
 	}
 	dev->stats.tx_errors++;
 	eth16i_reset(dev);
-	dev->trans_start = jiffies;
+	dev->trans_start = jiffies; /* prevent tx timeout */
 	outw(ETH16I_INTR_ON, ioaddr + TX_INTR_REG);
 	netif_wake_queue(dev);
 }
@@ -1109,7 +1109,6 @@
 		outb(TX_START | lp->tx_queue, ioaddr + TRANSMIT_START_REG);
 		lp->tx_queue = 0;
 		lp->tx_queue_len = 0;
-		dev->trans_start = jiffies;
 		lp->tx_started = 1;
 		netif_wake_queue(dev);
 	}