Re: [PATCH net-next v4 14/16] 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 for ETH_SS_TEST string count when CONFIG_NET_SELFTESTS is disabled causes a kernel warning in ethtool core.
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commit 5ea6a572f13e01c7caded35e30044420828ea41e
Author: Selvamani Rajagopal <Selvamani.Rajagopal@onsemi.com>

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

This commit splits the selftest support into a separate patch for the ease
of review.

> 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]
Will this cause a warning in the ethtool core if CONFIG_NET_SELFTESTS is
disabled?

When CONFIG_NET_SELFTESTS is disabled, net_selftest_get_count() returns 0.
If s2500_get_sset_count() returns 0 for ETH_SS_TEST, userspace requests
like ETHTOOL_TEST will pass a test length of 0 to the ethtool core.

The ethtool core function ethtool_self_test() expects a positive count and
triggers a warning (WARN_ON(test_len == 0)), which can crash systems with
panic_on_warn enabled.

Should this fall back to returning -EOPNOTSUPP when the test count is 0?

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Sashiko AI review · https://sashiko.dev/#/patchset/20260605-s2500-mac-phy-support-v4-0-de0fbc13c6d8@onsemi.com?part=14