Merge branch 'Fix-issues-in-tc-taprio-and-tc-cbs'

Vladimir Oltean says:

====================
Fix issues in tc-taprio and tc-cbs

This series fixes one panic and one WARN_ON found in the tc-taprio
qdisc, while trying to apply it:

- On an interface which is not multi-queue
- On an interface which has no carrier

The tc-cbs was also visually found to suffer of the same issue as
tc-taprio, and the fix was only compile-tested in that case.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 28 insertions, 22 deletions

diff --git a/net/sched/sch_cbs.c b/net/sched/sch_cbs.c
index 732e109c3055..810645b5c086 100644
--- a/net/sched/sch_cbs.c
+++ b/net/sched/sch_cbs.c
@@ -181,11 +181,6 @@ static struct sk_buff *cbs_dequeue_soft(struct Qdisc *sch)
 	s64 credits;
 	int len;
 
-	if (atomic64_read(&q->port_rate) == -1) {
-		WARN_ONCE(1, "cbs: dequeue() called with unknown port rate.");
-		return NULL;
-	}
-
 	if (q->credits < 0) {
 		credits = timediff_to_credits(now - q->last, q->idleslope);
 
@@ -303,11 +298,19 @@ static int cbs_enable_offload(struct net_device *dev, struct cbs_sched_data *q,
 static void cbs_set_port_rate(struct net_device *dev, struct cbs_sched_data *q)
 {
 	struct ethtool_link_ksettings ecmd;
+	int speed = SPEED_10;
 	int port_rate = -1;
+	int err;
+
+	err = __ethtool_get_link_ksettings(dev, &ecmd);
+	if (err < 0)
+		goto skip;
+
+	if (ecmd.base.speed != SPEED_UNKNOWN)
+		speed = ecmd.base.speed;
 
-	if (!__ethtool_get_link_ksettings(dev, &ecmd) &&
-	    ecmd.base.speed != SPEED_UNKNOWN)
-		port_rate = ecmd.base.speed * 1000 * BYTES_PER_KBIT;
+skip:
+	port_rate = speed * 1000 * BYTES_PER_KBIT;
 
 	atomic64_set(&q->port_rate, port_rate);
 	netdev_dbg(dev, "cbs: set %s's port_rate to: %lld, linkspeed: %d\n",
diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c
index e25d414ae12f..8d8bc2ec5cd6 100644
--- a/net/sched/sch_taprio.c
+++ b/net/sched/sch_taprio.c
@@ -477,11 +477,6 @@ static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
 	u32 gate_mask;
 	int i;
 
-	if (atomic64_read(&q->picos_per_byte) == -1) {
-		WARN_ONCE(1, "taprio: dequeue() called with unknown picos per byte.");
-		return NULL;
-	}
-
 	rcu_read_lock();
 	entry = rcu_dereference(q->current_entry);
 	/* if there's no entry, it means that the schedule didn't
@@ -958,12 +953,20 @@ static void taprio_set_picos_per_byte(struct net_device *dev,
 				      struct taprio_sched *q)
 {
 	struct ethtool_link_ksettings ecmd;
-	int picos_per_byte = -1;
+	int speed = SPEED_10;
+	int picos_per_byte;
+	int err;
 
-	if (!__ethtool_get_link_ksettings(dev, &ecmd) &&
-	    ecmd.base.speed != SPEED_UNKNOWN)
-		picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8,
-					   ecmd.base.speed * 1000 * 1000);
+	err = __ethtool_get_link_ksettings(dev, &ecmd);
+	if (err < 0)
+		goto skip;
+
+	if (ecmd.base.speed != SPEED_UNKNOWN)
+		speed = ecmd.base.speed;
+
+skip:
+	picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8,
+				   speed * 1000 * 1000);
 
 	atomic64_set(&q->picos_per_byte, picos_per_byte);
 	netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",
@@ -1249,6 +1252,10 @@ static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
 	 */
 	q->clockid = -1;
 
+	spin_lock(&taprio_list_lock);
+	list_add(&q->taprio_list, &taprio_list);
+	spin_unlock(&taprio_list_lock);
+
 	if (sch->parent != TC_H_ROOT)
 		return -EOPNOTSUPP;
 
@@ -1266,10 +1273,6 @@ static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
 	if (!opt)
 		return -EINVAL;
 
-	spin_lock(&taprio_list_lock);
-	list_add(&q->taprio_list, &taprio_list);
-	spin_unlock(&taprio_list_lock);
-
 	for (i = 0; i < dev->num_tx_queues; i++) {
 		struct netdev_queue *dev_queue;
 		struct Qdisc *qdisc;