1 files changed, 36 insertions, 6 deletions

diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index 2f2967dcf15a..bc18daa3ba51 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -234,8 +234,10 @@ static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 		prio = skb->priority;
 		tc = netdev_get_prio_tc_map(dev, prio);
 
-		if (!(gate_mask & BIT(tc)))
+		if (!(gate_mask & BIT(tc))) {
+			skb = NULL;
 			continue;
+		}
 
 		len = qdisc_pkt_len(skb);
 		guard = ktime_add_ns(q->get_time(),
@@ -245,13 +247,17 @@ static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 		 * guard band ...
 		 */
 		if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
-		    ktime_after(guard, entry->close_time))
+		    ktime_after(guard, entry->close_time)) {
+			skb = NULL;
 			continue;
+		}
 
 		/* ... and no budget. */
 		if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
-		    atomic_sub_return(len, &entry->budget) < 0)
+		    atomic_sub_return(len, &entry->budget) < 0) {
+			skb = NULL;
 			continue;
+		}
 
 		skb = child->ops->dequeue(child);
 		if (unlikely(!skb))
@@ -552,7 +558,7 @@ static int taprio_parse_mqprio_opt(struct net_device *dev,
 	}
 
 	/* Verify priority mapping uses valid tcs */
-	for (i = 0; i < TC_BITMASK + 1; i++) {
+	for (i = 0; i <= TC_BITMASK; i++) {
 		if (qopt->prio_tc_map[i] >= qopt->num_tc) {
 			NL_SET_ERR_MSG(extack, "Invalid traffic class in priority to traffic class mapping");
 			return -EINVAL;
@@ -709,6 +715,26 @@ static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
 	return NOTIFY_DONE;
 }
 
+static int taprio_mqprio_cmp(const struct net_device *dev,
+			     const struct tc_mqprio_qopt *mqprio)
+{
+	int i;
+
+	if (!mqprio || mqprio->num_tc != dev->num_tc)
+		return -1;
+
+	for (i = 0; i < mqprio->num_tc; i++)
+		if (dev->tc_to_txq[i].count != mqprio->count[i] ||
+		    dev->tc_to_txq[i].offset != mqprio->offset[i])
+			return -1;
+
+	for (i = 0; i <= TC_BITMASK; i++)
+		if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i])
+			return -1;
+
+	return 0;
+}
+
 static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
 			 struct netlink_ext_ack *extack)
 {
@@ -745,6 +771,10 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
 	admin = rcu_dereference(q->admin_sched);
 	rcu_read_unlock();
 
+	/* no changes - no new mqprio settings */
+	if (!taprio_mqprio_cmp(dev, mqprio))
+		mqprio = NULL;
+
 	if (mqprio && (oper || admin)) {
 		NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported");
 		err = -ENOTSUPP;
@@ -801,7 +831,7 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
 					    mqprio->offset[i]);
 
 		/* Always use supplied priority mappings */
-		for (i = 0; i < TC_BITMASK + 1; i++)
+		for (i = 0; i <= TC_BITMASK; i++)
 			netdev_set_prio_tc_map(dev, i,
 					       mqprio->prio_tc_map[i]);
 	}
@@ -877,7 +907,7 @@ static void taprio_destroy(struct Qdisc *sch)
 	}
 	q->qdiscs = NULL;
 
-	netdev_set_num_tc(dev, 0);
+	netdev_reset_tc(dev);
 
 	if (q->oper_sched)
 		call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb);