Re: [PATCH net-next v5 13/15] onsemi: s2500: Added selftest support to onsemi's S2500 driver

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Returning 0 from `get_sset_count` for `ETH_SS_TEST` triggers a `WARN_ON` in the ethtool core when `CONFIG_NET_SELFTESTS` is disabled.
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commit 8adb07a1816e950bf0dedebd55b13b3a9497928e
Author: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>

onsemi: s2500: Added selftest support to onsemi's S2500 driver

This commit introduces ethtool selftest support to the onsemi S2500 MAC-PHY
driver. It exposes selftests by handling the ETH_SS_TEST stringset and
registering the self_test callback in the ethtool operations.

> diff --git a/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c b/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c
> index 85bd8ea50dd8c..334fac71ddea2 100644
> --- a/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c
> +++ b/drivers/net/ethernet/onsemi/s2500/s2500_ethtool.c

[ ... ]

> @@ -229,6 +230,8 @@ static int s2500_get_sset_count(struct net_device *ndev, int sset)
>  	switch (sset) {
>  	case ETH_SS_STATS:
>  		return S2500_MAC_STATS_LEN;
> +	case ETH_SS_TEST:
> +		return net_selftest_get_count();

[Severity: Medium]
When CONFIG_NET_SELFTESTS is disabled, the dummy implementation of
net_selftest_get_count() defined in include/net/selftests.h returns 0.

Because the driver unconditionally registers the .self_test callback below
in s2500_ethtool_ops:

const struct ethtool_ops s2500_ethtool_ops = {
	...
	.self_test          = net_selftest,
};

Will returning 0 from s2500_get_sset_count() trigger a WARN_ON(test_len == 0)
in the ethtool core ioctl path when a user runs "ethtool -t"?

Could this check for a 0 test count and return -EOPNOTSUPP instead to avoid
the warning?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260614-s2500-mac-phy-support-v5-0-89874b72f725@onsemi.com?part=13