From fc8702a84b7e794ab95aac021aa2cc3b4c92c5cd Mon Sep 17 00:00:00 2001
From: Chengwen Feng <fengchengwen@huawei.com>
Date: Fri, 13 May 2022 10:53:54 +0800
Subject: [PATCH 092/122] net/axgbe: fix xstats get return if xstats is null
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Many user (e.g. telemetry) invokes rte_eth_xstats_get(port_id, NULL, 0)
to retrieve the required number of elements, but currently axgbe PMD
returns zero when xstats is null.

Remove the logic of "return zero when xstats is NULL", and add the logic
of "return the required number of entries when n is lower than the
required number of entries".

Fixes: 9d1ef6b2e731 ("net/axgbe: add xstats")
Cc: stable@dpdk.org

Signed-off-by: Chengwen Feng <fengchengwen@huawei.com>
Acked-by: Morten Brørup <mb@smartsharesystems.com>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
---
 drivers/net/axgbe/axgbe_ethdev.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/axgbe/axgbe_ethdev.c b/drivers/net/axgbe/axgbe_ethdev.c
index 7d40c18a86..b209ab67cf 100644
--- a/drivers/net/axgbe/axgbe_ethdev.c
+++ b/drivers/net/axgbe/axgbe_ethdev.c
@@ -1009,18 +1009,18 @@ axgbe_dev_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *stats,
 	struct axgbe_port *pdata = dev->data->dev_private;
 	unsigned int i;
 
-	if (!stats)
-		return 0;
+	if (n < AXGBE_XSTATS_COUNT)
+		return AXGBE_XSTATS_COUNT;
 
 	axgbe_read_mmc_stats(pdata);
 
-	for (i = 0; i < n && i < AXGBE_XSTATS_COUNT; i++) {
+	for (i = 0; i < AXGBE_XSTATS_COUNT; i++) {
 		stats[i].id = i;
 		stats[i].value = *(u64 *)((uint8_t *)&pdata->mmc_stats +
 				axgbe_xstats_strings[i].offset);
 	}
 
-	return i;
+	return AXGBE_XSTATS_COUNT;
 }
 
 static int
-- 
2.22.0

