ar71xx: Add GRO support to ag71xx

On a TL-WN710N, this patch increases iperf performance from ~92.5 to ~93.5 mbps. Keep in mind the WN710N is a 100mbps device. I expect greater numbers from gigabit devices.

Signed-off-by: Rosen Penev <rosenp@gmail.com>

target/linux/ar71xx/files/drivers/net/ethernet/atheros/ag71xx/ag71xx_main.c

@@ -1089,7 +1089,7 @@ next:
 
 	while ((skb = __skb_dequeue(&queue)) != NULL) {
 		skb->protocol = eth_type_trans(skb, dev);
-		netif_receive_skb(skb);
+		napi_gro_receive(&ag->napi, skb);
 	}
 
 	DBG("%s: rx finish, curr=%u, dirty=%u, done=%d\n",
@@ -1141,7 +1141,7 @@ static int ag71xx_poll(struct napi_struct *napi, int limit)
 		DBG("%s: disable polling mode, rx=%d, tx=%d,limit=%d\n",
 			dev->name, rx_done, tx_done, limit);
 
-		napi_complete(napi);
+		napi_complete_done(napi, rx_done);
 
 		/* enable interrupts */
 		spin_lock_irqsave(&ag->lock, flags);
@@ -1160,7 +1160,7 @@ oom:
 		pr_info("%s: out of memory\n", dev->name);
 
 	mod_timer(&ag->oom_timer, jiffies + AG71XX_OOM_REFILL);
-	napi_complete(napi);
+	napi_complete_done(napi, rx_done);
 	return 0;
 }