[dpdk-dev] [PATCH v2 04/15] net/enic: initialize RQ fetch index before enabling RQ

[John Daley <johndale@cisco.com>]

From: Hyong Youb Kim <hyonkim@cisco.com>

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")

Signed-off-by: Hyong Youb Kim <hyonkim@cisco.com>
Reviewed-by: John Daley <johndale@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 aba2ff5a7..863d2463c 100644
--- 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;
 }
-- 
2.16.2