From: Vinicius Costa Gomes vinicius.gomes@intel.com
[ Upstream commit 28aa7c86c2b49f659c8460a89e53b506c45979bb ]
When a application sends many packets with the same txtime, they may be transmitted out of order (different from the order in which they were enqueued).
This happens because when inserting elements into the tree, when the txtime of two packets are the same, the new packet is inserted at the left side of the tree, causing the reordering. The only effect of this change should be that packets with the same txtime will be transmitted in the order they are enqueued.
The application in question (the AVTP GStreamer plugin, still in development) is sending video traffic, in which each video frame have a single presentation time, the problem is that when packetizing, multiple packets end up with the same txtime.
The receiving side was rejecting packets because they were being received out of order.
Fixes: 25db26a91364 ("net/sched: Introduce the ETF Qdisc") Reported-by: Ederson de Souza ederson.desouza@intel.com Signed-off-by: Vinicius Costa Gomes vinicius.gomes@intel.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/sched/sch_etf.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/sched/sch_etf.c +++ b/net/sched/sch_etf.c @@ -177,7 +177,7 @@ static int etf_enqueue_timesortedlist(st
parent = *p; skb = rb_to_skb(parent); - if (ktime_after(txtime, skb->tstamp)) { + if (ktime_compare(txtime, skb->tstamp) >= 0) { p = &parent->rb_right; leftmost = false; } else {