cxgb4: don't offload Rx checksums for IPv6 fragments

The checksum provided by the device doesn't include the L3 headers,
as IPv6 expects.

Signed-off-by: Dimitris Michailidis <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

drivers/net/cxgb4/sge.c

···
 
 	if (csum_ok && (pi->rx_offload & RX_CSO) &&
 	    (pkt->l2info & htonl(RXF_UDP | RXF_TCP))) {
-		if (!pkt->ip_frag)
+		if (!pkt->ip_frag) {
 			skb->ip_summed = CHECKSUM_UNNECESSARY;
-		else {
+			rxq->stats.rx_cso++;
+		} else if (pkt->l2info & htonl(RXF_IP)) {
 			__sum16 c = (__force __sum16)pkt->csum;
 			skb->csum = csum_unfold(c);
 			skb->ip_summed = CHECKSUM_COMPLETE;
+			rxq->stats.rx_cso++;
 		}
-		rxq->stats.rx_cso++;
 	} else
 		skb->ip_summed = CHECKSUM_NONE;
 

drivers/net/cxgb4/t4_msg.h

···
 	__be32 l2info;
 #define RXF_UDP (1 << 22)
 #define RXF_TCP (1 << 23)
+#define RXF_IP  (1 << 24)
+#define RXF_IP6 (1 << 25)
 	__be16 hdr_len;
 	__be16 err_vec;
 };