diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index 0405e1f0d3df..fb6b232069d6 100644
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -1157,16 +1157,20 @@ static int mv643xx_eth_start_xmit(struct sk_buff *skb, struct net_device *dev)
 	if (!skb_shinfo(skb)->nr_frags) {
 linear:
 		if (skb->ip_summed != CHECKSUM_HW) {
+			/* Errata BTS #50, IHL must be 5 if no HW checksum */
 			pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT |
-					ETH_TX_FIRST_DESC | ETH_TX_LAST_DESC;
+					   ETH_TX_FIRST_DESC |
+					   ETH_TX_LAST_DESC |
+					   5 << ETH_TX_IHL_SHIFT;
 			pkt_info.l4i_chk = 0;
 		} else {
-			u32 ipheader = skb->nh.iph->ihl << 11;
 
 			pkt_info.cmd_sts = ETH_TX_ENABLE_INTERRUPT |
-					ETH_TX_FIRST_DESC | ETH_TX_LAST_DESC |
-					ETH_GEN_TCP_UDP_CHECKSUM |
-					ETH_GEN_IP_V_4_CHECKSUM | ipheader;
+					   ETH_TX_FIRST_DESC |
+					   ETH_TX_LAST_DESC |
+					   ETH_GEN_TCP_UDP_CHECKSUM |
+					   ETH_GEN_IP_V_4_CHECKSUM |
+					   skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
 			/* CPU already calculated pseudo header checksum. */
 			if (skb->nh.iph->protocol == IPPROTO_UDP) {
 				pkt_info.cmd_sts |= ETH_UDP_FRAME;
@@ -1193,7 +1197,6 @@ linear:
 		stats->tx_bytes += pkt_info.byte_cnt;
 	} else {
 		unsigned int frag;
-		u32 ipheader;
 
 		/* Since hardware can't handle unaligned fragments smaller
 		 * than 9 bytes, if we find any, we linearize the skb
@@ -1222,12 +1225,16 @@ linear:
 							DMA_TO_DEVICE);
 		pkt_info.l4i_chk = 0;
 		pkt_info.return_info = 0;
-		pkt_info.cmd_sts = ETH_TX_FIRST_DESC;
 
-		if (skb->ip_summed == CHECKSUM_HW) {
-			ipheader = skb->nh.iph->ihl << 11;
-			pkt_info.cmd_sts |= ETH_GEN_TCP_UDP_CHECKSUM |
-					ETH_GEN_IP_V_4_CHECKSUM | ipheader;
+		if (skb->ip_summed != CHECKSUM_HW)
+			/* Errata BTS #50, IHL must be 5 if no HW checksum */
+			pkt_info.cmd_sts = ETH_TX_FIRST_DESC |
+					   5 << ETH_TX_IHL_SHIFT;
+		else {
+			pkt_info.cmd_sts = ETH_TX_FIRST_DESC |
+					   ETH_GEN_TCP_UDP_CHECKSUM |
+					   ETH_GEN_IP_V_4_CHECKSUM |
+					   skb->nh.iph->ihl << ETH_TX_IHL_SHIFT;
 			/* CPU already calculated pseudo header checksum. */
 			if (skb->nh.iph->protocol == IPPROTO_UDP) {
 				pkt_info.cmd_sts |= ETH_UDP_FRAME;
diff --git a/drivers/net/mv643xx_eth.h b/drivers/net/mv643xx_eth.h
index 57c4f8fbfdb6..7678b59c2952 100644
--- a/drivers/net/mv643xx_eth.h
+++ b/drivers/net/mv643xx_eth.h
@@ -49,7 +49,7 @@
 /* Checksum offload for Tx works for most packets, but
  * fails if previous packet sent did not use hw csum
  */
-#undef	MV643XX_CHECKSUM_OFFLOAD_TX
+#define	MV643XX_CHECKSUM_OFFLOAD_TX
 #define	MV643XX_NAPI
 #define	MV643XX_TX_FAST_REFILL
 #undef	MV643XX_RX_QUEUE_FILL_ON_TASK	/* Does not work, yet */
@@ -217,6 +217,8 @@
 #define ETH_TX_ENABLE_INTERRUPT			(BIT23)
 #define ETH_AUTO_MODE				(BIT30)
 
+#define ETH_TX_IHL_SHIFT			11
+
 /* typedefs */
 
 typedef enum _eth_func_ret_status {