patch 'net/hns3: fix next-to-use overflow in SVE Tx' has been queued to stable release 21.11.3

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 21.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/01/22. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable/commit/540c8608d64bc2e8b1d6738606da87a65b3b50ea

Thanks.

Kevin

---
>From 540c8608d64bc2e8b1d6738606da87a65b3b50ea Mon Sep 17 00:00:00 2001
From: Chengwen Feng <fengchengwen at huawei.com>
Date: Mon, 5 Sep 2022 16:59:33 +0800
Subject: [PATCH] net/hns3: fix next-to-use overflow in SVE Tx

[ upstream commit 3efbc3c4027c87c14727a6a5ce13b099cd8d5866 ]

If txq's next-to-use plus nb_pkts equal txq's nb_tx_desc when using
SVE xmit algorithm, the txq's next-to-use will equal nb_tx_desc after
the xmit, this does not cause Tx exceptions, but may affect other ops
that depend on this field, such as tx_descriptor_status.

Fixes: f0c243a6cb6f ("net/hns3: support SVE Tx")

Signed-off-by: Chengwen Feng <fengchengwen at huawei.com>
Signed-off-by: Dongdong Liu <liudongdong3 at huawei.com>
---
 drivers/net/hns3/hns3_rxtx_vec_sve.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/net/hns3/hns3_rxtx_vec_sve.c b/drivers/net/hns3/hns3_rxtx_vec_sve.c
index b0dfb052bb..f09a81dbd5 100644
--- a/drivers/net/hns3/hns3_rxtx_vec_sve.c
+++ b/drivers/net/hns3/hns3_rxtx_vec_sve.c
@@ -465,5 +465,5 @@ hns3_xmit_fixed_burst_vec_sve(void *__restrict tx_queue,
 	}
 
-	if (txq->next_to_use + nb_pkts > txq->nb_tx_desc) {
+	if (txq->next_to_use + nb_pkts >= txq->nb_tx_desc) {
 		nb_tx = txq->nb_tx_desc - txq->next_to_use;
 		hns3_tx_fill_hw_ring_sve(txq, tx_pkts, nb_tx);
@@ -471,6 +471,8 @@ hns3_xmit_fixed_burst_vec_sve(void *__restrict tx_queue,
 	}
 
-	hns3_tx_fill_hw_ring_sve(txq, tx_pkts + nb_tx, nb_pkts - nb_tx);
-	txq->next_to_use += nb_pkts - nb_tx;
+	if (nb_pkts > nb_tx) {
+		hns3_tx_fill_hw_ring_sve(txq, tx_pkts + nb_tx, nb_pkts - nb_tx);
+		txq->next_to_use += nb_pkts - nb_tx;
+	}
 
 	txq->tx_bd_ready -= nb_pkts;
-- 
2.37.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-10-25 14:19:00.733916638 +0100
+++ 0097-net-hns3-fix-next-to-use-overflow-in-SVE-Tx.patch	2022-10-25 14:18:58.537798542 +0100
@@ -1 +1 @@
-From 3efbc3c4027c87c14727a6a5ce13b099cd8d5866 Mon Sep 17 00:00:00 2001
+From 540c8608d64bc2e8b1d6738606da87a65b3b50ea Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit 3efbc3c4027c87c14727a6a5ce13b099cd8d5866 ]
+
@@ -12 +13,0 @@
-Cc: stable at dpdk.org