Re: [PATCH v3 1/3] driver core: platform: remove software node on release()

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

On Tue, Apr 28, 2026 at 11:20:26AM +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).

...

> +	device_remove_software_node(dev);
>  	of_node_put(pa->pdev.dev.of_node);

So, why do we decide not to convert this to fwnode_handle_put() (and respective
_get() elsewhere)?

...

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

^^^ left for the context.

...

> +	/*
> +	 * If the primary firmware node is a software node and there's no
> +	 * secondary firmware node, the primary will be affected by the call
> +	 * to device_remove_software_node() in platform_device_release() and
> +	 * its reference count will be dropped by one. Take another reference
> +	 * here to make it have no effect.
> +	 */
> +	if (is_software_node(pdevinfo->fwnode) && !pdevinfo->swnode)
> +		fwnode_handle_get(pdevinfo->fwnode);

IIUC the `is_software_node(pdevinfo->fwnode) && pdevinfo->swnode` may not
happen here due to the above check. If I haven't missed anything, this check
is simply

	if (is_software_node(pdevinfo->fwnode))

-- 
With Best Regards,
Andy Shevchenko