Subject: Re: [PATCH V2 net-next 2/5] net: Introduce a new MII time stamping interface.

From: Richard Cochran <[email-masked]>
Date: Sun, 7 Oct 2018 14:20:33 -0700

On Sun, Oct 07, 2018 at 11:14:05PM +0200, Andrew Lunn wrote:
> The problem is you depend on skbuf->dev->phydev. phydev will be NULL.
> net_device does not currently have a phylink member. Even if it did,
> you end up add more and more tests looking every place a
> mii_timestamper could be placed.

Ok, so the way to do this is to have something like
CONFIG_NETWORK_PHYLINK_TIMESTAMPING.  We can deal with that if and
when any real devices appear.

> I'm currently thinking register_mii_timestamper() should take a netdev
> argument, and the net_device structure should gain a struct
> mii_timestamper.
> 
> But we have to look at the lifetime problems. A phydev does not know
> what netdev it is associated to until phy_connect() is called. It is
> at that point you can call register_mii_timestamper().

Right, IOW passing a netdev won't work.

Thanks,
Richard