Re: [PATCH net v2] net: ethtool: phy: warn about a phydev with no link topology

[Linkui Xiao <xiaolinkui@126.com>]

Hi,

On 2026/11/12 16:02, netdev-bot+sinfo@kernel.org wrote:
> Hi!
> 
> This is an automated message. This series looks like a fix, but its
> commit messages seem to be missing some information:
> 
>   - How the issue was discovered, e.g. hit in production, hit during
>     development, syzbot report, manual code inspection, LLM or static
>     analysis tool scan.
> 
> Please do not repost the series just to address the above. Instead,
> reply to this email with the missing information, so that reviewers
> can take it into account. If the series needs another revision for
> other reasons, please include the information in the commit messages
> then.
> 
> The evaluation is done by an LLM so it may be wrong, if you think
> that is the case please reply and explain.
Thanks for the reminder. The issue was found during an audit of
net/ethtool/ assisted by an LLM (Codex). The audit went through every
place that dereferences dev->link_topo, and phy_prepare_data() stood out
as the only one that does not cope with a missing topology. Following
that back led to the IBM EMAC driver assigning ndev->phydev by hand on
its fixed-link path, bypassing phy_attach_direct().

I verified the Fixes: commit (9dd2ad5e92b9) and both call paths (doit
and dump) by reading the code. The issue was not hit in production: no
in-tree DTS pairs "ibm,emac" with "fixed-link", so it is latent in
mainline and only out-of-tree users such as the Netgear WNDAP620 would
hit it.

As you suggested, I am not reposting the series for this. If a v3 is
needed for other reasons, I will fold this into the commit messages.

Thanks,
Linkui