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

[Maxime Chevallier]

On 6/15/26 16:10, Christian Marangi wrote:
> 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 at 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. 

I'll give it a go with this yeah, I have a few devices here I'd like to
try this on.

Can you CC me for the next rounds ?

Maxime

>