patch 'net/hns3: fix xstats get return if xstats is null' has been queued to stable release 21.11.2

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 21.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 06/13/22. 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/0072520fd5b67a2ed2c4b7af40bda0c2294dbcab

Thanks.

Kevin

---
>From 0072520fd5b67a2ed2c4b7af40bda0c2294dbcab Mon Sep 17 00:00:00 2001
From: Chengwen Feng <fengchengwen at huawei.com>
Date: Fri, 13 May 2022 10:53:51 +0800
Subject: [PATCH] net/hns3: fix xstats get return if xstats is null
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

[ upstream commit e15401f362779dba8623b4ee3db388fdf79dca7f ]

Many user (e.g. telemetry) invokes rte_eth_xstats_get(port_id, NULL, 0)
to retrieve the required number of elements, but currently hns3 PMD
returns zero when xstats is null.

Dedicated check for xstats vs null is not required, since ethdev layer
guarantees that it may be null only if number of entries n is 0 (which
is definitely smaller than total xstats count).

Fixes: 8839c5e202f3 ("net/hns3: support device stats")

Signed-off-by: Chengwen Feng <fengchengwen at huawei.com>
Acked-by: Morten Brørup <mb at smartsharesystems.com>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko at oktetlabs.ru>
---
 drivers/net/hns3/hns3_stats.c | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/drivers/net/hns3/hns3_stats.c b/drivers/net/hns3/hns3_stats.c
index 2799ff4432..07fad03485 100644
--- a/drivers/net/hns3/hns3_stats.c
+++ b/drivers/net/hns3/hns3_stats.c
@@ -1032,7 +1032,11 @@ hns3_imissed_stats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats,
  *   A pointer to a table of structure of type *rte_eth_xstat*
  *   to be filled with device statistics ids and values.
- *   This parameter can be set to NULL if n is 0.
+ *   This parameter can be set to NULL if and only if n is 0.
  * @param n
  *   The size of the xstats array (number of elements).
+ *   If lower than the required number of elements, the function returns the
+ *   required number of elements.
+ *   If equal to zero, the xstats parameter must be NULL, the function returns
+ *   the required number of elements.
  * @return
  *   0 on fail, count(The size of the statistics elements) on success.
@@ -1053,7 +1057,4 @@ hns3_dev_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats,
 	int ret;
 
-	if (xstats == NULL)
-		return 0;
-
 	count = hns3_xstats_calc_num(dev);
 	if ((int)n < count)
-- 
2.34.3

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2022-06-09 12:34:30.278443675 +0100
+++ 0021-net-hns3-fix-xstats-get-return-if-xstats-is-null.patch	2022-06-09 12:34:29.674980520 +0100
@@ -1 +1 @@
-From e15401f362779dba8623b4ee3db388fdf79dca7f Mon Sep 17 00:00:00 2001
+From 0072520fd5b67a2ed2c4b7af40bda0c2294dbcab Mon Sep 17 00:00:00 2001
@@ -8,0 +9,2 @@
+[ upstream commit e15401f362779dba8623b4ee3db388fdf79dca7f ]
+
@@ -18 +19,0 @@
-Cc: stable at dpdk.org