net: fec: fix receive VLAN CTAG HW acceleration issue

Nimrod Andy · davem330 · commit af5cbc9822f6 · 2015-03-10T13:37:01.000-04:00
The current driver support receive VLAN CTAG HW acceleration feature (NETIF_F_HW_VLAN_CTAG_RX) through software simulation. There calls the api .skb_copy_to_linear_data_offset() to skip the VLAN tag, but there have overlap between the two memory data point range. The patch just fix the issue. V2: Michael Grzeschik suggest to use memmove() instead of skb_copy_to_linear_data_offset(). Reported-by: Michael Grzeschik <m.grzeschik@pengutronix.de> Fixes: 1b7bde6 ("net: fec: implement rx_copybreak to improve rx performance") Signed-off-by: Fugang Duan <B38611@freescale.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
@@ -1479,8 +1479,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)
 
 			vlan_packet_rcvd = true;
 
-			skb_copy_to_linear_data_offset(skb, VLAN_HLEN,
-						       data, (2 * ETH_ALEN));
+			memmove(skb->data + VLAN_HLEN, data, ETH_ALEN * 2);
 			skb_pull(skb, VLAN_HLEN);
 		}
 

Original file line number	Diff line number	Diff line change
`@@ -1479,8 +1479,7 @@ fec_enet_rx_queue(struct net_device *ndev, int budget, u16 queue_id)`
`1479`	`1479`
`1480`	`1480`	`vlan_packet_rcvd = true;`
`1481`	`1481`
`1482`		`- skb_copy_to_linear_data_offset(skb, VLAN_HLEN,`
`1483`		`- data, (2 * ETH_ALEN));`
	`1482`	`+ memmove(skb->data + VLAN_HLEN, data, ETH_ALEN * 2);`
`1484`	`1483`	`skb_pull(skb, VLAN_HLEN);`
`1485`	`1484`	`}`
`1486`	`1485`