[PKT_SCHED]: Qdisc drop operation is optional
The drop operation is optional and qdiscs must check if childs support it.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sched/sch_netem.c b/net/sched/sch_netem.c
index ba52832..7228d30 100644
--- a/net/sched/sch_netem.c
+++ b/net/sched/sch_netem.c
@@ -252,9 +252,9 @@
static unsigned int netem_drop(struct Qdisc* sch)
{
struct netem_sched_data *q = qdisc_priv(sch);
- unsigned int len;
+ unsigned int len = 0;
- if ((len = q->qdisc->ops->drop(q->qdisc)) != 0) {
+ if (q->qdisc->ops->drop && (len = q->qdisc->ops->drop(q->qdisc)) != 0) {
sch->q.qlen--;
sch->qstats.drops++;
}