Re: [PATCH net-next v7 05/12] net: phylink: support late PCS provider attach

[Christian Marangi <ansuelsmth@gmail.com>]

On Mon, Jun 15, 2026 at 04:07:03PM +0200, Maxime Chevallier wrote:
> Hi Christian,
> 
> On 6/15/26 14:29, Christian Marangi wrote:
> > Add support for late PCS provider attachment to a phylink instance.
> > This works by creating a global notifier for the PCS provider and
> > making each phylink instance that makes use of fwnode subscribe to
> > this notifier.
> > 
> > The PCS notifier will emit the event FWNODE_PCS_PROVIDER_ADD every time
> > a new PCS provider is added.
> > 
> > phylink will then react to this event and will call the new function
> > fwnode_phylink_pcs_get_from_fwnode() that will check if the PCS fwnode
> > provided by the event is present in the pcs-handle property of the
> > phylink instance.
> > 
> > If a related PCS is found, then such PCS is added to the phylink
> > instance PCS list.
> > 
> > Then we link the PCS to the phylink instance and we refresh the supported
> > interfaces of the phylink instance.
> > 
> > Finally we check if we are in a major_config_failed scenario and trigger
> > an interface reconfiguration in the next phylink resolve.
> > 
> > In the example scenario where the link was previously torn down due to
> > removal of PCS, the link will be established again as the PCS came back
> > and is now available to phylink.
> > 
> > Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
> > ---
> 
> [...]
> 
> > @@ -2151,6 +2204,10 @@ void phylink_destroy(struct phylink *pl)
> >  	if (pl->link_gpio)
> >  		gpiod_put(pl->link_gpio);
> >  
> > +	/* Unregister notifier for late PCS attach */
> > +	if (pl->fwnode_pcs_nb.notifier_call)
> > +		unregister_fwnode_pcs_notifier(&pl->fwnode_pcs_nb);
> 
> I wanted to try this out, but I get :
> 
> drivers/net/phy/phylink.c:2218:17: error: implicit declaration of function ‘unregister_fwnode_pcs_notifier’; did you mean ‘register_fwnode_pcs_notifier’? [-Werror=implicit-function-declaration]
>  2218 |                 unregister_fwnode_pcs_notifier(&pl->fwnode_pcs_nb);
>       |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>       |                 register_fwnode_pcs_notifier
> 
> I guess you either need to stub this, or there's a missing Kconfig
> dependency somewhere
>

Hi yes if you want toi test just enable CONFIG_FWNODE_PCS. I forgot to add
the static declaration for unregister_fwnode_pcs_notifier. 

-- 
	Ansuel