ramips: Don't trigger BUG_ON due to skb allocation failure

Instead just drop the rx'ed frame silently and reuse the already
available buffer.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>

SVN-Revision: 24122

target/linux/ramips/files/drivers/net/ramips.c

@@ -272,6 +272,9 @@ ramips_eth_rx_hw(unsigned long ptr)
 			break;
 		max_rx--;
 
+		new_skb = netdev_alloc_skb(dev, MAX_RX_LENGTH + 2);
+		/* Reuse the buffer on allocation failures */
+		if (new_skb) {
 			rx_skb = priv->rx_skb[rx];
 			skb_put(rx_skb, RX_DMA_PLEN0(priv->rx[rx].rxd2));
 			rx_skb->dev = dev;
@@ -281,14 +284,14 @@ ramips_eth_rx_hw(unsigned long ptr)
 			dev->stats.rx_bytes += rx_skb->len;
 			netif_rx(rx_skb);
 
-		new_skb = netdev_alloc_skb(dev, MAX_RX_LENGTH + 2);
 			priv->rx_skb[rx] = new_skb;
-		BUG_ON(!new_skb);
 			skb_reserve(new_skb, 2);
 			priv->rx[rx].rxd1 = dma_map_single(NULL,
 							   new_skb->data,
 							   MAX_RX_LENGTH + 2,
 							   DMA_FROM_DEVICE);
+		}
+
 		priv->rx[rx].rxd2 &= ~RX_DMA_DONE;
 		wmb();
 		ramips_fe_wr(rx, RAMIPS_RX_CALC_IDX0);