[dpdk-stable] [PATCH] net/enic: fix packet loss after MTU change

[John Daley]

If multiple Rx queues and Rx Scatter are used and the MTU is
modified so that the number of mbufs per packet changes, packet
loss is possible.

The enic completion queue index was miscalculated leaving the
upper half of the queues uninitialized after an MTU change, possibly
leading to completions on those queues not getting processed.

Fixes: c3e09182bcd6 ("net/enic: support scatter Rx in MTU update")
Cc: stable at dpdk.org

Signed-off-by: John Daley <johndale at cisco.com>
---
 drivers/net/enic/enic_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index 521167063..793260504 100644
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -1119,11 +1119,12 @@ static int
 enic_reinit_rq(struct enic *enic, unsigned int rq_idx)
 {
 	struct vnic_rq *sop_rq, *data_rq;
-	unsigned int cq_idx = enic_cq_rq(enic, rq_idx);
+	unsigned int cq_idx;
 	int rc = 0;
 
 	sop_rq = &enic->rq[enic_rte_rq_idx_to_sop_idx(rq_idx)];
 	data_rq = &enic->rq[enic_rte_rq_idx_to_data_idx(rq_idx)];
+	cq_idx = rq_idx;
 
 	vnic_cq_clean(&enic->cq[cq_idx]);
 	vnic_cq_init(&enic->cq[cq_idx],
-- 
2.12.0