fix mvneta vlan tagging

This is a 3.14.x backport of:
"mvneta: Fix TSO and checksum for non-acceleration vlan traffic"

Upstream commits:

817dbfa5d1bc276a72c1a577310382008e8aca0a
2d39d120781a5770573dc6ed672a5a562f541aea

Fixes vlan tagging on SoC interfaces for the WRT1900AC.  Useful
when using mvsw6171 driver.

Signed-off-by: Mark Milburn <mark.a.milburn@gmail.com>
Signed-off-by: Imre Kaloz <kaloz@openwrt.org>

SVN-Revision: 43781

target/linux/mvebu/patches-3.14/110-mvneta_fix_tso_and_chksum.patch

@@ -0,0 +1,38 @@
+--- a/drivers/net/ethernet/marvell/mvneta.c
++++ b/drivers/net/ethernet/marvell/mvneta.c
+@@ -20,6 +20,7 @@
+ #include <linux/mbus.h>
+ #include <linux/module.h>
+ #include <linux/interrupt.h>
++#include <linux/if_vlan.h>
+ #include <net/ip.h>
+ #include <net/ipv6.h>
+ #include <linux/io.h>
+@@ -1380,15 +1381,16 @@ static u32 mvneta_skb_tx_csum(struct mvn
+ {
+ 	if (skb->ip_summed == CHECKSUM_PARTIAL) {
+ 		int ip_hdr_len = 0;
++		__be16 l3_proto = vlan_get_protocol(skb);
+ 		u8 l4_proto;
+ 
+-		if (skb->protocol == htons(ETH_P_IP)) {
++		if (l3_proto == htons(ETH_P_IP)) {
+ 			struct iphdr *ip4h = ip_hdr(skb);
+ 
+ 			/* Calculate IPv4 checksum and L4 checksum */
+ 			ip_hdr_len = ip4h->ihl;
+ 			l4_proto = ip4h->protocol;
+-		} else if (skb->protocol == htons(ETH_P_IPV6)) {
++		} else if (l3_proto == htons(ETH_P_IPV6)) {
+ 			struct ipv6hdr *ip6h = ipv6_hdr(skb);
+ 
+ 			/* Read l4_protocol from one of IPv6 extra headers */
+@@ -1399,7 +1401,7 @@ static u32 mvneta_skb_tx_csum(struct mvn
+ 			return MVNETA_TX_L4_CSUM_NOT;
+ 
+ 		return mvneta_txq_desc_csum(skb_network_offset(skb),
+-				skb->protocol, ip_hdr_len, l4_proto);
++					l3_proto, ip_hdr_len, l4_proto);
+ 	}
+ 
+ 	return MVNETA_TX_L4_CSUM_NOT;