diff --git a/sys/dev/ic/bwfm.c b/sys/dev/ic/bwfm.c
index f9e66a46ba55..5be22a11aa00 100644
--- a/sys/dev/ic/bwfm.c
+++ b/sys/dev/ic/bwfm.c
@@ -337,7 +337,7 @@ bwfm_start(struct ifnet *ifp)
 			continue;
 		}
 
-		error = sc->sc_bus_ops->bs_txdata(sc, m);
+		error = sc->sc_bus_ops->bs_txdata(sc, &m);
 		if (error == ENOBUFS) {
 			IF_PREPEND(&ifp->if_snd, m);
 			ifp->if_flags |= IFF_OACTIVE;
diff --git a/sys/dev/ic/bwfmvar.h b/sys/dev/ic/bwfmvar.h
index e836152d0d7c..1dbc3f22cf7f 100644
--- a/sys/dev/ic/bwfmvar.h
+++ b/sys/dev/ic/bwfmvar.h
@@ -93,7 +93,7 @@ struct bwfm_bus_ops {
 	void (*bs_init)(struct bwfm_softc *);
 	void (*bs_stop)(struct bwfm_softc *);
 	int (*bs_txcheck)(struct bwfm_softc *);
-	int (*bs_txdata)(struct bwfm_softc *, struct mbuf *);
+	int (*bs_txdata)(struct bwfm_softc *, struct mbuf **);
 	int (*bs_txctl)(struct bwfm_softc *, char *, size_t);
 	int (*bs_rxctl)(struct bwfm_softc *, char *, size_t *);
 };
diff --git a/sys/dev/pci/if_bwfm_pci.c b/sys/dev/pci/if_bwfm_pci.c
index 696b8382f81c..b30d585ce83a 100644
--- a/sys/dev/pci/if_bwfm_pci.c
+++ b/sys/dev/pci/if_bwfm_pci.c
@@ -225,7 +225,7 @@ void		 bwfm_pci_dmamem_free(struct bwfm_pci_softc *, struct bwfm_pci_dmamem *);
 int		 bwfm_pci_pktid_avail(struct bwfm_pci_softc *,
 		    struct bwfm_pci_pkts *);
 int		 bwfm_pci_pktid_new(struct bwfm_pci_softc *,
-		    struct bwfm_pci_pkts *, struct mbuf *,
+		    struct bwfm_pci_pkts *, struct mbuf **,
 		    uint32_t *, paddr_t *);
 struct mbuf *	 bwfm_pci_pktid_free(struct bwfm_pci_softc *,
 		    struct bwfm_pci_pkts *, uint32_t);
@@ -281,7 +281,7 @@ void		 bwfm_pci_flowring_delete(struct bwfm_pci_softc *, int);
 
 void		 bwfm_pci_stop(struct bwfm_softc *);
 int		 bwfm_pci_txcheck(struct bwfm_softc *);
-int		 bwfm_pci_txdata(struct bwfm_softc *, struct mbuf *);
+int		 bwfm_pci_txdata(struct bwfm_softc *, struct mbuf **);
 
 #ifdef BWFM_DEBUG
 void		 bwfm_pci_debug_console(struct bwfm_pci_softc *);
@@ -922,7 +922,7 @@ bwfm_pci_pktid_avail(struct bwfm_pci_softc *sc, struct bwfm_pci_pkts *pkts)
 
 int
 bwfm_pci_pktid_new(struct bwfm_pci_softc *sc, struct bwfm_pci_pkts *pkts,
-    struct mbuf *m, uint32_t *pktid, paddr_t *paddr)
+    struct mbuf **mp, uint32_t *pktid, paddr_t *paddr)
 {
 	int i, idx;
 
@@ -932,15 +932,30 @@ bwfm_pci_pktid_new(struct bwfm_pci_softc *sc, struct bwfm_pci_pkts *pkts,
 			idx = 0;
 		if (pkts->pkts[idx].bb_m == NULL) {
 			if (bus_dmamap_load_mbuf(sc->sc_dmat,
-			    pkts->pkts[idx].bb_map, m, BUS_DMA_NOWAIT) != 0) {
-				if (m_defrag(m, M_DONTWAIT))
-					return EFBIG;
+			    pkts->pkts[idx].bb_map, *mp, BUS_DMA_NOWAIT) != 0) {
+				/*
+				 * Didn't fit.  Maybe it has too many
+				 * segments.  If it has only one
+				 * segment, fail; otherwise try to
+				 * compact it into a single mbuf
+				 * segment.
+				 */
+				if ((*mp)->m_next == NULL)
+					return ENOBUFS;
+				struct mbuf *m0 = MCLGETI(NULL, M_DONTWAIT,
+				    NULL, MSGBUF_MAX_PKT_SIZE);
+				if (m0 == NULL)
+					return ENOBUFS;
+				m_copydata(*mp, 0, (*mp)->m_pkthdr.len,
+				    mtod(m0, void *));
+				m_freem(*mp);
+				*mp = m0;
 				if (bus_dmamap_load_mbuf(sc->sc_dmat,
-				    pkts->pkts[idx].bb_map, m, BUS_DMA_NOWAIT) != 0)
+				    pkts->pkts[idx].bb_map, *mp, BUS_DMA_NOWAIT) != 0)
 					return EFBIG;
 			}
 			pkts->last = idx;
-			pkts->pkts[idx].bb_m = m;
+			pkts->pkts[idx].bb_m = *mp;
 			*pktid = idx;
 			*paddr = pkts->pkts[idx].bb_map->dm_segs[0].ds_addr;
 			return 0;
@@ -997,7 +1012,7 @@ bwfm_pci_fill_rx_ioctl_ring(struct bwfm_pci_softc *sc, struct if_rxring *rxring,
 			break;
 		}
 		m->m_len = m->m_pkthdr.len = MSGBUF_MAX_PKT_SIZE;
-		if (bwfm_pci_pktid_new(sc, &sc->sc_rx_pkts, m, &pktid, &paddr)) {
+		if (bwfm_pci_pktid_new(sc, &sc->sc_rx_pkts, &m, &pktid, &paddr)) {
 			bwfm_pci_ring_write_cancel(sc, &sc->sc_ctrl_submit, 1);
 			m_freem(m);
 			break;
@@ -1037,7 +1052,7 @@ bwfm_pci_fill_rx_buf_ring(struct bwfm_pci_softc *sc)
 			break;
 		}
 		m->m_len = m->m_pkthdr.len = MSGBUF_MAX_PKT_SIZE;
-		if (bwfm_pci_pktid_new(sc, &sc->sc_rx_pkts, m, &pktid, &paddr)) {
+		if (bwfm_pci_pktid_new(sc, &sc->sc_rx_pkts, &m, &pktid, &paddr)) {
 			bwfm_pci_ring_write_cancel(sc, &sc->sc_rxpost_submit, 1);
 			m_freem(m);
 			break;
@@ -1388,7 +1403,7 @@ bwfm_pci_msg_rx(struct bwfm_pci_softc *sc, void *buf)
 		if (ring->m != NULL) {
 			m = ring->m;
 			ring->m = NULL;
-			if (bwfm_pci_txdata(&sc->sc_sc, m))
+			if (bwfm_pci_txdata(&sc->sc_sc, &m))
 				m_freem(ring->m);
 		}
 		ifp->if_flags &= ~IFF_OACTIVE;
@@ -1851,7 +1866,7 @@ bwfm_pci_txcheck(struct bwfm_softc *bwfm)
 }
 
 int
-bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
+bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf **mp)
 {
 	struct bwfm_pci_softc *sc = (void *)bwfm;
 	struct bwfm_pci_msgring *ring;
@@ -1861,7 +1876,7 @@ bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
 	struct ether_header *eh;
 	int flowid, ret, ac;
 
-	flowid = bwfm_pci_flowring_lookup(sc, m);
+	flowid = bwfm_pci_flowring_lookup(sc, *mp);
 	if (flowid < 0) {
 		/*
 		 * We cannot send the packet right now as there is
@@ -1872,7 +1887,7 @@ bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
 		 * is created the queue will be restarted and this
 		 * mbuf will be transmitted.
 		 */
-		bwfm_pci_flowring_create(sc, m);
+		bwfm_pci_flowring_create(sc, *mp);
 		return 0;
 	}
 
@@ -1890,9 +1905,9 @@ bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
 		return ENOBUFS;
 
 	/* No QoS for EAPOL frames. */
-	eh = mtod(m, struct ether_header *);
+	eh = mtod(*mp, struct ether_header *);
 	ac = (eh->ether_type != htons(ETHERTYPE_PAE)) ?
-	    M_WME_GETAC(m) : WME_AC_BE;
+	    M_WME_GETAC(*mp) : WME_AC_BE;
 
 	memset(tx, 0, sizeof(*tx));
 	tx->msg.msgtype = MSGBUF_TYPE_TX_POST;
@@ -1900,9 +1915,9 @@ bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
 	tx->flags = BWFM_MSGBUF_PKT_FLAGS_FRAME_802_3;
 	tx->flags |= ac << BWFM_MSGBUF_PKT_FLAGS_PRIO_SHIFT;
 	tx->seg_cnt = 1;
-	memcpy(tx->txhdr, mtod(m, char *), ETHER_HDR_LEN);
+	memcpy(tx->txhdr, mtod(*mp, char *), ETHER_HDR_LEN);
 
-	ret = bwfm_pci_pktid_new(sc, &sc->sc_tx_pkts, m, &pktid, &paddr);
+	ret = bwfm_pci_pktid_new(sc, &sc->sc_tx_pkts, mp, &pktid, &paddr);
 	if (ret) {
 		if (ret == ENOBUFS) {
 			printf("%s: no pktid available for TX\n",
@@ -1915,7 +1930,7 @@ bwfm_pci_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
 	paddr += ETHER_HDR_LEN;
 
 	tx->msg.request_id = htole32(pktid);
-	tx->data_len = htole16(m->m_len - ETHER_HDR_LEN);
+	tx->data_len = htole16((*mp)->m_len - ETHER_HDR_LEN);
 	tx->data_buf_addr.high_addr = htole32(paddr >> 32);
 	tx->data_buf_addr.low_addr = htole32(paddr & 0xffffffff);
 
diff --git a/sys/dev/usb/if_bwfm_usb.c b/sys/dev/usb/if_bwfm_usb.c
index f264b3e746e9..d1a44ed7679f 100644
--- a/sys/dev/usb/if_bwfm_usb.c
+++ b/sys/dev/usb/if_bwfm_usb.c
@@ -203,7 +203,7 @@ int		 bwfm_usb_alloc_tx_list(struct bwfm_usb_softc *);
 void		 bwfm_usb_free_tx_list(struct bwfm_usb_softc *);
 
 int		 bwfm_usb_txcheck(struct bwfm_softc *);
-int		 bwfm_usb_txdata(struct bwfm_softc *, struct mbuf *);
+int		 bwfm_usb_txdata(struct bwfm_softc *, struct mbuf **);
 int		 bwfm_usb_txctl(struct bwfm_softc *, char *, size_t);
 int		 bwfm_usb_rxctl(struct bwfm_softc *, char *, size_t *);
 
@@ -785,9 +785,10 @@ bwfm_usb_txcheck(struct bwfm_softc *bwfm)
 
 
 int
-bwfm_usb_txdata(struct bwfm_softc *bwfm, struct mbuf *m)
+bwfm_usb_txdata(struct bwfm_softc *bwfm, struct mbuf **mp)
 {
 	struct bwfm_usb_softc *sc = (void *)bwfm;
+	struct mbuf *m = *mp;
 	struct bwfm_proto_bcdc_hdr *hdr;
 	struct bwfm_usb_tx_data *data;
 	struct ether_header *eh;