make sure if_transmit returns 0 if the mbuf is enqueued.

ixgbe/ixv.c still needs a similar fix but it takes a little
more restructuring of the code.

MFC after:	3 days

3 files changed, 5 insertions, 6 deletions

diff --git a/sys/dev/e1000/if_igb.c b/sys/dev/e1000/if_igb.c
index 2322e56..39a7df6 100644
--- a/sys/dev/e1000/if_igb.c
+++ b/sys/dev/e1000/if_igb.c
@@ -989,12 +989,12 @@ igb_mq_start(struct ifnet *ifp, struct mbuf *m)
 	if (err)
 		return (err);
 	if (IGB_TX_TRYLOCK(txr)) {
-		err = igb_mq_start_locked(ifp, txr);
+		igb_mq_start_locked(ifp, txr);
 		IGB_TX_UNLOCK(txr);
 	} else
 		taskqueue_enqueue(que->tq, &txr->txq_task);
 
-	return (err);
+	return (0);
 }
 
 static int
diff --git a/sys/dev/ixgbe/ixgbe.c b/sys/dev/ixgbe/ixgbe.c
index c3b3fd6..774827c 100644
--- a/sys/dev/ixgbe/ixgbe.c
+++ b/sys/dev/ixgbe/ixgbe.c
@@ -831,12 +831,12 @@ ixgbe_mq_start(struct ifnet *ifp, struct mbuf *m)
 	if (err)
 		return (err);
 	if (IXGBE_TX_TRYLOCK(txr)) {
-		err = ixgbe_mq_start_locked(ifp, txr);
+		ixgbe_mq_start_locked(ifp, txr);
 		IXGBE_TX_UNLOCK(txr);
 	} else
 		taskqueue_enqueue(que->tq, &txr->txq_task);
 
-	return (err);
+	return (0);
 }
 
 static int
diff --git a/sys/dev/vmware/vmxnet3/if_vmx.c b/sys/dev/vmware/vmxnet3/if_vmx.c
index e349770..cb9214f 100644
--- a/sys/dev/vmware/vmxnet3/if_vmx.c
+++ b/sys/dev/vmware/vmxnet3/if_vmx.c
@@ -2935,7 +2935,6 @@ vmxnet3_txq_mq_start_locked(struct vmxnet3_txqueue *txq, struct mbuf *m)
 		/* Assume worse case if this mbuf is the head of a chain. */
 		if (m->m_next != NULL && avail < VMXNET3_TX_MAXSEGS) {
 			drbr_putback(ifp, br, m);
-			error = ENOBUFS;
 			break;
 		}
 
@@ -2958,7 +2957,7 @@ vmxnet3_txq_mq_start_locked(struct vmxnet3_txqueue *txq, struct mbuf *m)
 		txq->vxtxq_watchdog = VMXNET3_WATCHDOG_TIMEOUT;
 	}
 
-	return (error);
+	return (0);
 }
 
 static int