Re: [PATCH net-next] ppp: enable TX scatter-gather

Qingfang Deng <[email protected]> Tue, 16 Sep 2025 10:57:49 +0800
Newsgroups org.kernel.vger.linux-ppp,org.kernel.vger.linux-kernel,org.kernel.vger.netdev
Message-ID <CALW65jYgDYxXfWFmwYBjXfNtqWqZ7VDWPYsbzAH_EzcRtyn0DQ@mail.gmail.com>
Hi Jakub,

On Tue, Sep 16, 2025 at 9:10 AM Jakub Kicinski <[email protected]> wrote:
> Seems a bit racy. We can't netdev_update_features() under the spin lock
> so there's going to be a window of time where datapath will see new
> state but netdev flags won't be cleared, yet?
>
> We either need to add a explicit linearization check in the xmit path,
> or always reset the flags to disabled before we start tweaking the
> config and re-enable after config (tho the latter feels like a bit of
> a hack).

Can I modify dev->features directly under the spin lock (without
.ndo_fix_features) ?

> --
> pw-bot: cr