3 files changed, 29 insertions, 17 deletions

diff --git a/sys/dev/bfe/if_bfe.c b/sys/dev/bfe/if_bfe.c
index ba69c541a652..805cd2669e19 100644
--- a/sys/dev/bfe/if_bfe.c
+++ b/sys/dev/bfe/if_bfe.c
@@ -1357,7 +1357,7 @@ bfe_start(struct ifnet *ifp)
 {
 	struct bfe_softc *sc;
 	struct mbuf *m_head = NULL;
-	int idx;
+	int idx, queued = 0;
 
 	sc = ifp->if_softc;
 	idx = sc->bfe_tx_prod;
@@ -1393,6 +1393,8 @@ bfe_start(struct ifnet *ifp)
 			break;
 		}
 
+		queued++;
+
 		/*
 		 * If there's a BPF listener, bounce a copy of this frame
 		 * to him.
@@ -1400,15 +1402,18 @@ bfe_start(struct ifnet *ifp)
 		BPF_MTAP(ifp, m_head);
 	}
 
-	sc->bfe_tx_prod = idx;
-	/* Transmit - twice due to apparent hardware bug */
-	CSR_WRITE_4(sc, BFE_DMATX_PTR, idx * sizeof(struct bfe_desc));
-	CSR_WRITE_4(sc, BFE_DMATX_PTR, idx * sizeof(struct bfe_desc));
+	if (queued) {
+		sc->bfe_tx_prod = idx;
+		/* Transmit - twice due to apparent hardware bug */
+		CSR_WRITE_4(sc, BFE_DMATX_PTR, idx * sizeof(struct bfe_desc));
+		CSR_WRITE_4(sc, BFE_DMATX_PTR, idx * sizeof(struct bfe_desc));
+
+		/*
+		 * Set a timeout in case the chip goes out to lunch.
+		 */
+		ifp->if_timer = 5;
+	}
 
-	/*
-	 * Set a timeout in case the chip goes out to lunch.
-	 */
-	ifp->if_timer = 5;
 	BFE_UNLOCK(sc);
 }
 
diff --git a/sys/dev/if_ndis/if_ndis.c b/sys/dev/if_ndis/if_ndis.c
index 48da1f8efd18..2412cf082070 100644
--- a/sys/dev/if_ndis/if_ndis.c
+++ b/sys/dev/if_ndis/if_ndis.c
@@ -1291,6 +1291,9 @@ ndis_start(ifp)
 			break;
 	}
 
+	if (pcnt == 0)
+		return;
+
 	if (sc->ndis_txpending == 0)
 		ifp->if_flags |= IFF_OACTIVE;
 
diff --git a/sys/pci/if_sis.c b/sys/pci/if_sis.c
index 6a30c7effa13..0fe85ab4ea27 100644
--- a/sys/pci/if_sis.c
+++ b/sys/pci/if_sis.c
@@ -1954,7 +1954,7 @@ sis_start(ifp)
 {
 	struct sis_softc	*sc;
 	struct mbuf		*m_head = NULL;
-	u_int32_t		idx;
+	u_int32_t		idx, queued = 0;
 
 	sc = ifp->if_softc;
 	SIS_LOCK(sc);
@@ -1982,6 +1982,8 @@ sis_start(ifp)
 			break;
 		}
 
+		queued++;
+
 		/*
 		 * If there's a BPF listener, bounce a copy of this frame
 		 * to him.
@@ -1990,14 +1992,16 @@ sis_start(ifp)
 
 	}
 
-	/* Transmit */
-	sc->sis_cdata.sis_tx_prod = idx;
-	SIS_SETBIT(sc, SIS_CSR, SIS_CSR_TX_ENABLE);
+	if (queued) {
+		/* Transmit */
+		sc->sis_cdata.sis_tx_prod = idx;
+		SIS_SETBIT(sc, SIS_CSR, SIS_CSR_TX_ENABLE);
 
-	/*
-	 * Set a timeout in case the chip goes out to lunch.
-	 */
-	ifp->if_timer = 5;
+		/*
+		 * Set a timeout in case the chip goes out to lunch.
+		 */
+		ifp->if_timer = 5;
+	}
 
 	SIS_UNLOCK(sc);