- Remove the reserved number of TX descriptors. No limitation is mentioned in

  the 8139C+/8169/8110/8168/8101/8111 datasheets and it seems to work ok
  without reserving the descriptors.
- Change allowable number of TX DMA segments to 32.

From FreeBSD

ok chris@

2 files changed, 6 insertions, 11 deletions

diff --git a/sys/dev/ic/re.c b/sys/dev/ic/re.c
index 0f14dda7510..e55712637be 100644
--- a/sys/dev/ic/re.c
+++ b/sys/dev/ic/re.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: re.c,v 1.141 2013/03/11 23:42:19 brad Exp $	*/
+/*	$OpenBSD: re.c,v 1.142 2013/03/17 20:47:23 brad Exp $	*/
 /*	$FreeBSD: if_re.c,v 1.31 2004/09/04 07:54:05 ru Exp $	*/
 /*
  * Copyright (c) 1997, 1998-2003
@@ -1067,8 +1067,7 @@ re_attach(struct rl_softc *sc, const char *intrstr)
 	/* Create DMA maps for TX buffers */
 	for (i = 0; i < RL_TX_QLEN; i++) {
 		error = bus_dmamap_create(sc->sc_dmat,
-		    RL_JUMBO_FRAMELEN,
-		    RL_TX_DESC_CNT(sc) - RL_NTXDESC_RSVD, RL_TDESC_CMD_FRAGLEN,
+		    RL_JUMBO_FRAMELEN, RL_NTXSEGS, RL_JUMBO_FRAMELEN,
 		    0, 0, &sc->rl_ldata.rl_txq[i].txq_dmamap);
 		if (error) {
 			printf("%s: can't create DMA map for TX\n",
@@ -1592,8 +1591,7 @@ re_txeof(struct rl_softc *sc)
 
 	sc->rl_ldata.rl_txq_considx = idx;
 
-	if (sc->rl_ldata.rl_tx_free > RL_NTXDESC_RSVD)
-		ifp->if_flags &= ~IFF_OACTIVE;
+	ifp->if_flags &= ~IFF_OACTIVE;
 
 	/*
 	 * Some chips will ignore a second TX request issued while an
@@ -1731,9 +1729,6 @@ re_encap(struct rl_softc *sc, struct mbuf *m, int *idx)
 	u_int32_t	cmdstat, vlanctl = 0, csum_flags = 0;
 	struct rl_txq	*txq;
 
-	if (sc->rl_ldata.rl_tx_free <= RL_NTXDESC_RSVD)
-		return (EFBIG);
-
 	/*
 	 * Set up checksum offload. Note: checksum offload bits must
 	 * appear in all descriptors of a multi-descriptor transmit
@@ -1784,7 +1779,7 @@ re_encap(struct rl_softc *sc, struct mbuf *m, int *idx)
 		nsegs++;
 	}
 
-	if (nsegs > sc->rl_ldata.rl_tx_free - RL_NTXDESC_RSVD) {
+	if (sc->rl_ldata.rl_tx_free - nsegs <= 1) {
 		error = EFBIG;
 		goto fail_unload;
 	}
diff --git a/sys/dev/ic/rtl81x9reg.h b/sys/dev/ic/rtl81x9reg.h
index 8f2f44b9279..cf7b658d904 100644
--- a/sys/dev/ic/rtl81x9reg.h
+++ b/sys/dev/ic/rtl81x9reg.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: rtl81x9reg.h,v 1.75 2012/04/08 08:34:55 jsg Exp $	*/
+/*	$OpenBSD: rtl81x9reg.h,v 1.76 2013/03/17 20:47:23 brad Exp $	*/
 
 /*
  * Copyright (c) 1997, 1998
@@ -685,7 +685,7 @@ struct rl_stats {
 
 #define RL_TX_QLEN		64
 
-#define RL_NTXDESC_RSVD		4
+#define RL_NTXSEGS		32
 
 #define RL_RX_LIST_SZ		(RL_RX_DESC_CNT * sizeof(struct rl_desc))
 #define RL_RING_ALIGN		256