From 55d27673fcf51d2938190ba2067a7acab701b3a4 Mon Sep 17 00:00:00 2001 From: Vinicius Costa Gomes Date: Thu, 6 Feb 2020 13:46:06 -0800 Subject: [PATCH] taprio: Fix enabling offload with wrong number of traffic classes If the driver implementing taprio offloading depends on the value of the network device number of traffic classes (dev->num_tc) for whatever reason, it was going to receive the value zero. The value was only set after the offloading function is called. So, moving setting the number of traffic classes to before the offloading function is called fixes this issue. This is safe because this only happens when taprio is instantiated (we don't allow this configuration to be changed without first removing taprio). Fixes: 6f3f73366f14 ("taprio: Add support for hardware offloading") Reported-by: Po Liu Signed-off-by: Vinicius Costa Gomes Acked-by: Vladimir Oltean Signed-off-by: David S. Miller --- net/sched/sch_taprio.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) diff --git a/net/sched/sch_taprio.c b/net/sched/sch_taprio.c index c609373c86618..ad0dadcfcdba8 100644 --- a/net/sched/sch_taprio.c +++ b/net/sched/sch_taprio.c @@ -1444,6 +1444,19 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, taprio_set_picos_per_byte(dev, q); + if (mqprio) { + netdev_set_num_tc(dev, mqprio->num_tc); + for (i = 0; i < mqprio->num_tc; i++) + netdev_set_tc_queue(dev, i, + mqprio->count[i], + mqprio->offset[i]); + + /* Always use supplied priority mappings */ + for (i = 0; i <= TC_BITMASK; i++) + netdev_set_prio_tc_map(dev, i, + mqprio->prio_tc_map[i]); + } + if (FULL_OFFLOAD_IS_ENABLED(taprio_flags)) err = taprio_enable_offload(dev, mqprio, q, new_admin, extack); else @@ -1471,19 +1484,6 @@ static int taprio_change(struct Qdisc *sch, struct nlattr *opt, q->advance_timer.function = advance_sched; } - if (mqprio) { - netdev_set_num_tc(dev, mqprio->num_tc); - for (i = 0; i < mqprio->num_tc; i++) - netdev_set_tc_queue(dev, i, - mqprio->count[i], - mqprio->offset[i]); - - /* Always use supplied priority mappings */ - for (i = 0; i <= TC_BITMASK; i++) - netdev_set_prio_tc_map(dev, i, - mqprio->prio_tc_map[i]); - } - if (FULL_OFFLOAD_IS_ENABLED(taprio_flags)) { q->dequeue = taprio_dequeue_offload; q->peek = taprio_peek_offload; -- 2.39.5