Index: head/sys/dev/sfxge/sfxge.c
===================================================================
--- head/sys/dev/sfxge/sfxge.c
+++ head/sys/dev/sfxge/sfxge.c
@@ -65,8 +65,7 @@
 		   IFCAP_JUMBO_MTU | IFCAP_LRO |			\
 		   IFCAP_VLAN_HWTSO | IFCAP_LINKSTATE | IFCAP_HWSTATS)
 #define	SFXGE_CAP_ENABLE SFXGE_CAP
-#define	SFXGE_CAP_FIXED (IFCAP_VLAN_MTU | IFCAP_RXCSUM | IFCAP_VLAN_HWCSUM | \
-			 IFCAP_RXCSUM_IPV6 |				\
+#define	SFXGE_CAP_FIXED (IFCAP_VLAN_MTU | IFCAP_VLAN_HWCSUM |		\
 			 IFCAP_JUMBO_MTU | IFCAP_LINKSTATE | IFCAP_HWSTATS)
 
 MALLOC_DEFINE(M_SFXGE, "sfxge", "Solarflare 10GigE driver");
Index: head/sys/dev/sfxge/sfxge_rx.c
===================================================================
--- head/sys/dev/sfxge/sfxge_rx.c
+++ head/sys/dev/sfxge/sfxge_rx.c
@@ -795,7 +795,8 @@
 sfxge_rx_qcomplete(struct sfxge_rxq *rxq, boolean_t eop)
 {
 	struct sfxge_softc *sc = rxq->sc;
-	int lro_enabled = sc->ifnet->if_capenable & IFCAP_LRO;
+	int if_capenable = sc->ifnet->if_capenable;
+	int lro_enabled = if_capenable & IFCAP_LRO;
 	unsigned int index;
 	struct sfxge_evq *evq;
 	unsigned int completed;
@@ -825,21 +826,37 @@
 
 		prefetch_read_many(mtod(m, caddr_t));
 
-		/* Check for loopback packets */
-		if (!(rx_desc->flags & EFX_PKT_IPV4) &&
-		    !(rx_desc->flags & EFX_PKT_IPV6)) {
-			struct ether_header *etherhp;
-
-			/*LINTED*/
-			etherhp = mtod(m, struct ether_header *);
-
-			if (etherhp->ether_type ==
-			    htons(SFXGE_ETHERTYPE_LOOPBACK)) {
-				EFSYS_PROBE(loopback);
-
-				rxq->loopback++;
-				goto discard;
+		switch (rx_desc->flags & (EFX_PKT_IPV4 | EFX_PKT_IPV6)) {
+		case EFX_PKT_IPV4:
+			if (~if_capenable & IFCAP_RXCSUM)
+				rx_desc->flags &=
+				    ~(EFX_CKSUM_IPV4 | EFX_CKSUM_TCPUDP);
+			break;
+		case EFX_PKT_IPV6:
+			if (~if_capenable & IFCAP_RXCSUM_IPV6)
+				rx_desc->flags &= ~EFX_CKSUM_TCPUDP;
+			break;
+		case 0:
+			/* Check for loopback packets */
+			{
+				struct ether_header *etherhp;
+
+				/*LINTED*/
+				etherhp = mtod(m, struct ether_header *);
+
+				if (etherhp->ether_type ==
+				    htons(SFXGE_ETHERTYPE_LOOPBACK)) {
+					EFSYS_PROBE(loopback);
+
+					rxq->loopback++;
+					goto discard;
+				}
 			}
+			break;
+		default:
+			KASSERT(B_FALSE,
+			    ("Rx descriptor with both IPv4 and IPv6 flags"));
+			goto discard;
 		}
 
 		/* Pass packet up the stack or into LRO (pipelined) */