Re: [PATCH net-next v3] net: phy: make the hwtstamp provider lifetime symmetric with the PHY

[Jakub Kicinski <kuba@kernel.org>]

On Wed, 23 Sep 2026 15:11:32 +0800 Chenguang Zhao wrote:
> phy_detach() removes dev->hwprov when it points at the PHY being
> detached, but phy_attach() does not install anything: the setup and
> teardown are not symmetric. The teardown path is also reached from
> the probe error path with no RTNL and an unregistered netdev, making
> rtnl_dereference() of dev->hwprov trigger a lockdep splat.
> 
> Track the provider with the PHY instead: dev_attach_hwtstamp_phylib()
> installs a default provider in phy_attach_direct(), and
> dev_clear_hwtstamp_phylib() removes it in phy_detach(). Both sit
> next to dev_set_hwtstamp_phylib() so the locking is obviously the
> same, relaxed for unregistered netdevs via
> netdev_ops_lock_dereference_or_invisible(). No driver callback is
> invoked; installation is skipped when the PHY is not the default
> hwtstamp provider or when ethtool already set one.

This is pure slop, you added this incredibly ugly
netdev_ops_lock_dereference_or_invisible()
instead of just taking the RCU lock.

Please don't send send any patches to networking for the next 2 months
and use this time to learn kernel programming basics.
-- 
pw-bot: reject
pv-ban: 2mo