Re: [PATCH net-next 4/4] selftests: drv-net: ncdevmem: configure and restore HDS threshold

[Stanislav Fomichev <stfomichev@gmail.com>]

On 08/22, Jakub Kicinski wrote:
> Improve HDS handling. Make sure we set threshold to 0.
> Restore the previous settings before exiting.
> 
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
> ---
>  .../selftests/drivers/net/hw/ncdevmem.c       | 96 +++++++++++++++++--
>  1 file changed, 87 insertions(+), 9 deletions(-)
> 
> diff --git a/tools/testing/selftests/drivers/net/hw/ncdevmem.c b/tools/testing/selftests/drivers/net/hw/ncdevmem.c
> index 580b4459a840..aa2904d1a3e1 100644
> --- a/tools/testing/selftests/drivers/net/hw/ncdevmem.c
> +++ b/tools/testing/selftests/drivers/net/hw/ncdevmem.c
> @@ -419,6 +419,60 @@ static const char *tcp_data_split_str(int val)
>  	}
>  }
>  
> +static struct ethtool_rings_get_rsp *get_ring_config(void)
> +{
> +	struct ethtool_rings_get_req *get_req;
> +	struct ethtool_rings_get_rsp *get_rsp;
> +	struct ynl_error yerr;
> +	struct ynl_sock *ys;
> +
> +	ys = ynl_sock_create(&ynl_ethtool_family, &yerr);
> +	if (!ys) {
> +		fprintf(stderr, "YNL: %s\n", yerr.msg);
> +		return NULL;
> +	}
> +
> +	get_req = ethtool_rings_get_req_alloc();
> +	ethtool_rings_get_req_set_header_dev_index(get_req, ifindex);
> +	get_rsp = ethtool_rings_get(ys, get_req);
> +	ethtool_rings_get_req_free(get_req);
> +
> +	ynl_sock_destroy(ys);
> +
> +	return get_rsp;
> +}
> +
> +static void restore_ring_config(const struct ethtool_rings_get_rsp *config)
> +{
> +	struct ethtool_rings_set_req *req;
> +	struct ynl_error yerr;
> +	struct ynl_sock *ys;
> +	int ret;
> +
> +	if (!config)
> +		return;
> +
> +	ys = ynl_sock_create(&ynl_ethtool_family, &yerr);
> +	if (!ys) {
> +		fprintf(stderr, "YNL: %s\n", yerr.msg);
> +		return;
> +	}
> +
> +	req = ethtool_rings_set_req_alloc();
> +	ethtool_rings_set_req_set_header_dev_index(req, ifindex);
> +	ethtool_rings_set_req_set_tcp_data_split(req,
> +						ETHTOOL_TCP_DATA_SPLIT_UNKNOWN);
> +	if (config->_present.hds_thresh)
> +		ethtool_rings_set_req_set_hds_thresh(req, config->hds_thresh);
> +
> +	ret = ethtool_rings_set(ys, req);
> +	if (ret < 0)
> +		fprintf(stderr, "YNL failed: %s\n", ys->err.msg);
> +	ethtool_rings_set_req_free(req);
> +
> +	ynl_sock_destroy(ys);
> +}
> +
>  static int configure_headersplit(bool on)
>  {
>  	struct ethtool_rings_get_req *get_req;
> @@ -436,8 +490,14 @@ static int configure_headersplit(bool on)
>  
>  	req = ethtool_rings_set_req_alloc();
>  	ethtool_rings_set_req_set_header_dev_index(req, ifindex);
> -	/* 0 - off, 1 - auto, 2 - on */
> -	ethtool_rings_set_req_set_tcp_data_split(req, on ? 2 : 0);
> +	if (on) {
> +		ethtool_rings_set_req_set_tcp_data_split(req,
> +						ETHTOOL_TCP_DATA_SPLIT_ENABLED);
> +		ethtool_rings_set_req_set_hds_thresh(req, 0);

From talking to Taehee awhile ago it seemed like unconditionally
setting 0 will fail on the devices that don't support it.
Is it not the case anymore with ethnl_set_rings_validate?