Re: [PATCH v4 1/2] software node: return -ENOTCONN when referenced swnode is not registered yet

Bartosz Golaszewski
2026-04-08T15:52:09Z

On Wed, 8 Apr 2026 17:28:46 +0200, Danilo Krummrich <dakr@kernel.org> said:
> On Wed Apr 8, 2026 at 9:19 AM CEST, Bartosz Golaszewski wrote:
>> On Tue, Apr 7, 2026 at 3:28 PM Bartosz Golaszewski
>> <bartosz.golaszewski@oss.qualcomm.com> wrote:
>>>
>>> It's possible that at the time of resolving a reference to a remote
>>> software node, the node we know exists is not yet registered as a full
>>> firmware node. We currently return -ENOENT in this case but the same
>>> error code is also returned in some other cases, like the reference
>>> property with given name not existing in the property list of the local
>>> software node.
>>>
>>> It makes sense to let users know that we're dealing with an unregistered
>>> software node so that they can defer probe - the situation is somewhat
>>> similar to there existing a firmware node to which no device is bound
>>> yet - which is valid grounds for probe deferral. To that end: use
>>> -ENOTCONN to indicate the software node is "not connected".
>>>
>>> Acked-by: Andy Shevchenko <andy@kernel.org>
>>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
>>> ---
>>
>> Hi Danilo!
>>
>> With Andy's Ack, do you think you could still queue this for v7.1?
>
> Yeah, that should work, but I have a question about the patch.
>
> The comment added to fwnode_property_get_reference_args() says:
>
> + * %-ENOTCONN when the remote firmware node is a software node that
> + * has not been registered as a firmware node yet
>
> This seems like a bit of a layering violation to me, as it makes it explicit
> that this error code indicates a software node, while
> fwnode_property_get_reference_args() itself should be agnostic.
>
> The caller can easily derive more specific semantics with an is_software_node()
> check as you already do in the GPIO code.
>
> Can we describe the same condition, but without explicitly naming the backend?
>

Yes, sure. It can be something like:

%-ENOTCONN when the remote firmware node exists but has not been
registered yet.

Does this sound good and doo you want me to resend or can you change it
when applying?

Bart