Re: [PATCH v3 1/8] driver core: add a faux bus for use when a simple device/bus is needed

[Zijun Hu]

On 2/7/2025 1:38 AM, Greg Kroah-Hartman wrote:
> +#include "base.h"
> +
> +#define MAX_FAUX_NAME_SIZE	256	/* Max size of a faux_device name */

Remove this macro?

> ++ */

<snip>

> +struct faux_device *faux_device_create_with_groups(const char *name,
> +						   const struct faux_device_ops *faux_ops,
> +						   const struct attribute_group **groups)
> +{
> +	struct device *dev;
> +	struct faux_object *faux_obj;
> +	struct faux_device *faux_dev;
> +	int name_size;

Remove @name_size?

> +	int ret;
> +
> +	name_size = strlen(name);
> +	if (name_size > MAX_FAUX_NAME_SIZE)
> +		return NULL;
> +

Remove above block related to @name_size

> +	faux_obj = kzalloc(sizeof(*faux_obj) + name_size + 1, GFP_KERNEL);

faux_obj = kzalloc(sizeof(*faux_obj), GFP_KERNEL);

> +	if (!faux_obj)
> +		return NULL;
> +
> +	/* Save off the callbacks so we can use them in the future */
> +	faux_obj->faux_ops = faux_ops;
> +
> +	/* Initialize the device portion and register it with the driver core */
> +	faux_dev = &faux_obj->faux_dev;
> +	dev = &faux_dev->dev;
> +
> +	device_initialize(dev);
> +	dev->release = faux_device_release;
> +	dev->parent = &faux_bus_root;
> +	dev->bus = &faux_bus_type;
> +	dev->groups = groups;
> +	dev_set_name(dev, "%s", name);
> +
> +	ret = device_add(dev);
> +	if (ret) {
> +		pr_err("%s: device_add for faux device '%s' failed with %d\n",
> +		       __func__, name, ret);
> +		put_device(dev);
> +		return NULL;
> +	}
> +
> +	return faux_dev;
> +}
> +EXPORT_SYMBOL_GPL(faux_device_create_with_groups);

<snip>

> ++int __init faux_bus_init(void)
> +{
> +	int ret;
> +
> +	ret = device_register(&faux_bus_root);
> +	if (ret) {
> +		put_device(&faux_bus_root);
> +		return ret;
> +	}
> +
> +	ret = bus_register(&faux_bus_type);
> +	if (ret)
> +		goto error_bus;
> +
> +	ret = driver_register(&faux_driver);
> +	if (ret)
> +		goto error_driver;
> +
> +	return ret;

return 0;

> +
> +error_driver:
> +	bus_unregister(&faux_bus_type);
> +
> +error_bus:
> +	device_unregister(&faux_bus_root);
> +	return ret;
> +}

<snip>