[PATCH v2 2/9] net/hns3: adjust retval when xstats is null of get xstats

[Min Hu (Connor)]

Acked-by: Min Hu (Connor) <humin29 at huawei.com>

在 2022/4/28 21:15, Chengwen Feng 写道:
> 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.
> 
> This patch adjusts that the return value was the required number of
> elements when stats is NULL.
> 
> Fixes: 8839c5e202f3 ("net/hns3: support device stats")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Chengwen Feng <fengchengwen at huawei.com>
> ---
>   drivers/net/hns3/hns3_stats.c | 7 ++-----
>   1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/net/hns3/hns3_stats.c b/drivers/net/hns3/hns3_stats.c
> index 806720faff..4165e22f7f 100644
> --- a/drivers/net/hns3/hns3_stats.c
> +++ b/drivers/net/hns3/hns3_stats.c
> @@ -1020,7 +1020,7 @@ hns3_imissed_stats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats,
>    * @praram 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.
> + *   If set to NULL, the function returns the required number of elements.
>    * @param n
>    *   The size of the xstats array (number of elements).
>    * @return
> @@ -1041,11 +1041,8 @@ hns3_dev_xstats_get(struct rte_eth_dev *dev, struct rte_eth_xstat *xstats,
>   	int count;
>   	int ret;
>   
> -	if (xstats == NULL)
> -		return 0;
> -
>   	count = hns3_xstats_calc_num(dev);
> -	if ((int)n < count)
> +	if (xstats == NULL || (int)n < count)
>   		return count;
>   
>   	count = 0;
>