5 files changed, 20 insertions, 6 deletions

diff --git a/net/sched/sch_fifo.c b/net/sched/sch_fifo.c
index b3075f8a196b..f7290d2542c2 100644
--- a/net/sched/sch_fifo.c
+++ b/net/sched/sch_fifo.c
@@ -64,11 +64,13 @@ static int pfifo_tail_enqueue(struct sk_buff *skb, struct Qdisc *sch)
 static int fifo_init(struct Qdisc *sch, struct nlattr *opt)
 {
 	struct fifo_sched_data *q = qdisc_priv(sch);
+	bool bypass;
+	bool is_bfifo = sch->ops == &bfifo_qdisc_ops;
 
 	if (opt == NULL) {
 		u32 limit = qdisc_dev(sch)->tx_queue_len ? : 1;
 
-		if (sch->ops == &bfifo_qdisc_ops)
+		if (is_bfifo)
 			limit *= psched_mtu(qdisc_dev(sch));
 
 		q->limit = limit;
@@ -81,6 +83,15 @@ static int fifo_init(struct Qdisc *sch, struct nlattr *opt)
 		q->limit = ctl->limit;
 	}
 
+	if (is_bfifo)
+		bypass = q->limit >= psched_mtu(qdisc_dev(sch));
+	else
+		bypass = q->limit >= 1;
+
+	if (bypass)
+		sch->flags |= TCQ_F_CAN_BYPASS;
+	else
+		sch->flags &= ~TCQ_F_CAN_BYPASS;
 	return 0;
 }
 
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index cc17e794c41e..0da09d508737 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -527,6 +527,8 @@ static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
 	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
 		skb_queue_head_init(band2list(priv, prio));
 
+	/* Can by-pass the queue discipline */
+	qdisc->flags |= TCQ_F_CAN_BYPASS;
 	return 0;
 }
 
@@ -691,9 +693,6 @@ static void attach_one_default_qdisc(struct net_device *dev,
 			netdev_info(dev, "activation failed\n");
 			return;
 		}
-
-		/* Can by-pass the queue discipline for default qdisc */
-		qdisc->flags |= TCQ_F_CAN_BYPASS;
 	}
 	dev_queue->qdisc_sleeping = qdisc;
 }
diff --git a/net/sched/sch_mq.c b/net/sched/sch_mq.c
index ecc302f4d2a1..ec5cbc848963 100644
--- a/net/sched/sch_mq.c
+++ b/net/sched/sch_mq.c
@@ -61,7 +61,6 @@ static int mq_init(struct Qdisc *sch, struct nlattr *opt)
 						    TC_H_MIN(ntx + 1)));
 		if (qdisc == NULL)
 			goto err;
-		qdisc->flags |= TCQ_F_CAN_BYPASS;
 		priv->qdiscs[ntx] = qdisc;
 	}
 
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 8620c65f480a..fbc6f53cb1b7 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -130,7 +130,6 @@ static int mqprio_init(struct Qdisc *sch, struct nlattr *opt)
 			err = -ENOMEM;
 			goto err;
 		}
-		qdisc->flags |= TCQ_F_CAN_BYPASS;
 		priv->qdiscs[i] = qdisc;
 	}
 
diff --git a/net/sched/sch_sfq.c b/net/sched/sch_sfq.c
index 156ad30980b5..fdba52aa053d 100644
--- a/net/sched/sch_sfq.c
+++ b/net/sched/sch_sfq.c
@@ -560,6 +560,10 @@ static int sfq_init(struct Qdisc *sch, struct nlattr *opt)
 		slot_queue_init(&q->slots[i]);
 		sfq_link(q, i);
 	}
+	if (q->limit >= 1)
+		sch->flags |= TCQ_F_CAN_BYPASS;
+	else
+		sch->flags &= ~TCQ_F_CAN_BYPASS;
 	return 0;
 }
 
@@ -611,6 +615,8 @@ static unsigned long sfq_get(struct Qdisc *sch, u32 classid)
 static unsigned long sfq_bind(struct Qdisc *sch, unsigned long parent,
 			      u32 classid)
 {
+	/* we cannot bypass queue discipline anymore */
+	sch->flags &= ~TCQ_F_CAN_BYPASS;
 	return 0;
 }