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

Jakub Kicinski <[email protected]> Wed, 17 Sep 2025 14:14:34 -0700
Newsgroups org.kernel.vger.linux-ppp,org.kernel.vger.linux-kernel,org.kernel.vger.netdev
Message-ID <[email protected]>
On Wed, 17 Sep 2025 19:00:16 +0800 Qingfang Deng wrote:
> On Tue, Sep 16, 2025 at 10:57 PM Jakub Kicinski <[email protected]> wrote:
> >
> > On Tue, 16 Sep 2025 10:57:49 +0800 Qingfang Deng wrote:  
> > > Can I modify dev->features directly under the spin lock (without
> > > .ndo_fix_features) ?  
> >
> > Hm, I'm not aware of a reason not to. You definitely need to hold
> > rtnl_lock, and call netdev_update_features() after.  
> 
> Will the modification race against __netdev_update_features(), where
> dev->features is assigned a new value?

Shouldn't race if we're holding rtnl_lock when we make the modification
and until we call netdev_update_features()? I'm just spitballing tho,
haven't studied the code.