Simplify the code dealing with the mbuf chain in dp8390_get().

From bad@ & mycroft@ NetBSD

Tested by nick@

1 files changed, 25 insertions, 27 deletions

diff --git a/sys/dev/ic/dp8390.c b/sys/dev/ic/dp8390.c
index 7277211190b..87bc051ffae 100644
--- a/sys/dev/ic/dp8390.c
+++ b/sys/dev/ic/dp8390.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dp8390.c,v 1.32 2006/09/17 18:03:06 brad Exp $	*/
+/*	$OpenBSD: dp8390.c,v 1.33 2006/10/03 20:06:21 brad Exp $	*/
 /*	$NetBSD: dp8390.c,v 1.13 1998/07/05 06:49:11 jonathan Exp $	*/
 
 /*
@@ -155,7 +155,7 @@ dp8390_mediachange(ifp)
 	if (sc->sc_mediachange)
 		return ((*sc->sc_mediachange)(sc));
 
-	return (EINVAL);
+	return (0);
 }
 
 /*
@@ -1016,41 +1016,29 @@ dp8390_get(sc, src, total_len)
 	u_short total_len;
 {
 	struct ifnet *ifp = &sc->sc_arpcom.ac_if;
-	struct mbuf *top, **mp, *m;
+	struct mbuf *m, *m0, *newm;
 	u_short len;
 
-	MGETHDR(m, M_DONTWAIT, MT_DATA);
-	if (m == 0)
-		return 0;
-	m->m_pkthdr.rcvif = ifp;
-	m->m_pkthdr.len = total_len;
+	MGETHDR(m0, M_DONTWAIT, MT_DATA);
+	if (m0 == 0)
+		return (0);
+	m0->m_pkthdr.rcvif = ifp;
+	m0->m_pkthdr.len = total_len;
 	len = MHLEN;
-	top = 0;
-	mp = ⊤
+	m = m0;
 
 	while (total_len > 0) {
-		if (top) {
-			MGET(m, M_DONTWAIT, MT_DATA);
-			if (m == 0) {
-				m_freem(top);
-				return 0;
-			}
-			len = MLEN;
-		}
 		if (total_len >= MINCLSIZE) {
 			MCLGET(m, M_DONTWAIT);
-			if ((m->m_flags & M_EXT) == 0) {
-				m_freem(m);
-				m_freem(top);
-				return 0;
-			}
+			if ((m->m_flags & M_EXT) == 0)
+				goto bad;
 			len = MCLBYTES;
 		}
 
 		/*
 		 * Make sure the data after the Ethernet header is aligned.
 		 */
-		if (top == NULL) {
+		if (m == m0) {
 			caddr_t newdata = (caddr_t)
 			    ALIGN(m->m_data + sizeof(struct ether_header)) -
 			    sizeof(struct ether_header);
@@ -1063,12 +1051,22 @@ dp8390_get(sc, src, total_len)
 			src = (*sc->ring_copy)(sc, src, mtod(m, caddr_t), len);
 		else
 			src = dp8390_ring_copy(sc, src, mtod(m, caddr_t), len);
+
 		total_len -= len;
-		*mp = m;
-		mp = &m->m_next;
+		if (total_len > 0) {
+			MGET(newm, M_DONTWAIT, MT_DATA);
+			if (newm == 0)
+				goto bad;
+			len = MLEN;
+			m = m->m_next = newm;
+		}
 	}
 
-	return top;
+	return (m0);
+
+bad:
+	m_freem(m0);
+	return (0);
 }