net/enic: initialize RQ fetch index before enabling RQ

The fetch index must be initialized only when RQ is
disabled. Otherwise, it may lead to stale entries in IG descriptor
cache on the VIC.

Fixes: a74629cfa3a1 ("net/enic: enable RQ first and then post Rx buffers")
Cc: stable@dpdk.org
Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>
Reviewed-by: John Daley <johndale@cisco.com>

diff --git a/drivers/net/enic/enic_main.c b/drivers/net/enic/enic_main.c
index aba2ff5a705f3532d0cdd378ba59adeff37a48a5..863d2463c98ff8f5b6b3d076376fb672b37753cc 100644 (file)
--- a/drivers/net/enic/enic_main.c
+++ b/drivers/net/enic/enic_main.c
@@ -320,6 +320,8 @@ enic_alloc_rx_queue_mbufs(struct enic *enic, struct vnic_rq *rq)
         * enic_start_rq().
         */
        rq->need_initial_post = true;
+       /* Initialize fetch index while RQ is disabled */
+       iowrite32(0, &rq->ctrl->fetch_index);
        return 0;
 }
 
@@ -345,7 +347,6 @@ enic_initial_post_rx(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();
        rq->need_initial_post = false;
 }