Re: [dpdk-dev] [PATCH] net/af_xdp: fix xdp_get_channels_info return value

[Stephen Hemminger <stephen@networkplumber.org>]

On Fri, 12 Jul 2019 09:55:46 +0200
Július Milan <jmilan.dev@gmail.com> wrote:

> Procedure xdp_get_channels_info was returning error code -1 in case of
> ioctl command SIOCETHTOOL was not supported. This patch sets return
> value back to 0 as it is valid case.
> 
> Fixes: 339b88c6a9 ("net/af_xdp: support multi-queue")
> 
> Signed-off-by: Július Milan <jmilan.dev@gmail.com>
> ---
>  drivers/net/af_xdp/rte_eth_af_xdp.c | 10 +++++++---
>  1 file changed, 7 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index ff8e90589..33352e10a 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -852,9 +852,13 @@ xdp_get_channels_info(const char *if_name, int *max_queues,
>  	ifr.ifr_data = (void *)&channels;
>  	strncpy(ifr.ifr_name, if_name, IFNAMSIZ);
>  	ret = ioctl(fd, SIOCETHTOOL, &ifr);
> -	if (ret && errno != EOPNOTSUPP) {
> -		ret = -errno;
> -		goto out;
> +	if (ret) {
> +		if (errno == EOPNOTSUPP) {
> +			ret = 0;
> +		} else {
> +			ret = -errno;
> +			goto out;
> +		}
>  	}
>  
>  	if (channels.max_combined == 0 || errno == EOPNOTSUPP) {

Still wrong, it doesn't set max_queues/combined_queues if errno == EOPNOTSUPP