If you stop then start a port that had already received some packets, the NIC could fetch discriptors from the wrong location. This could effectivly reduce the size of the Rx queue by a random amount and cause packet drop or reduced performance.
Reset the NIC fetch index to 0 when allocating and posting mbuf addresses to the NIC. Fixes: 947d860c821f ("enic: improve Rx performance") Signed-off-by: John Daley <johndale at cisco.com> Reviewed-by: Nelson Escobar <neescoba at cisco.com> --- drivers/net/enic/enic_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c index dc831b4..0475cc1 100644 --- a/drivers/net/enic/enic_main.c +++ b/drivers/net/enic/enic_main.c @@ -334,6 +334,7 @@ enic_alloc_rx_queue_mbufs(struct enic *enic, struct vnic_rq *rq) dev_debug(enic, "port=%u, qidx=%u, Write %u posted idx, %u sw held\n", enic->port_id, rq->index, rq->posted_index, rq->rx_nb_hold); iowrite32(rq->posted_index, &rq->ctrl->posted_index); + iowrite32(0, &rq->ctrl->fetch_index); rte_rmb(); return 0; -- 2.7.0