Re: [PATCH v4 1/3] driver core: platform: remove software node on release()

[Andy Shevchenko <andriy.shevchenko@intel.com>]

On Thu, Apr 30, 2026 at 09:46:04AM +0200, Bartosz Golaszewski wrote:
> If we pass a software node to a newly created device using struct
> platform_device_info, it will not be removed when the device is
> released. This may happen when a module creating the device is removed
> or on failure in platform_device_add().
> 
> When we try to reuse that software node in a subsequent call to
> platform_device_register_full(), it will fails with -EBUSY. Add the
> missing call to device_remove_software_node() in release path.
> 
> In addition to the above change, make sure that we still function
> correctly if a software node is used as the primary firmware node as
> well as disallow using two software nodes for platform devices as
> device_add_software_node() does not handle this case correctly (in fact
> a comment inside it states that only one software node per device is
> allowed but it will not bail out if two are used so we need to handle it
> here).

...

> -	if (pdevinfo->swnode && pdevinfo->properties)
> +	/*
> +	 * Only one software node per device is allowed. Make sure we don't
> +	 * accept or create two.
> +	 */
> +	if ((pdevinfo->swnode && pdevinfo->properties) ||
> +	    (pdevinfo->swnode && is_software_node(pdevinfo->fwnode)) ||
> +	    (pdevinfo->properties && is_software_node(pdevinfo->fwnode)))
>  		return ERR_PTR(-EINVAL);

This makes me think of why we have these many ways of doing things...
Perhaps we should kill pdevinfo::properties completely?

Second thought is what about actually refusing this on the level of
device_add_software_node()? And looking at it, we have that check
there, why do we need it here then? Did we miss to check error code from
device_add_software_node() somewhere?

-- 
With Best Regards,
Andy Shevchenko