Re: [PATCH net-next 2/6] net: wan: framer: make framer_class constant

[Simon Horman <horms@kernel.org>]

+ Herve Codina <herve.codina@bootlin.com>

On Sat, Mar 02, 2024 at 02:05:58PM -0300, Ricardo B. Marliere wrote:
> Since commit 43a7206b0963 ("driver core: class: make class_register() take
> a const *"), the driver core allows for struct class to be in read-only
> memory, so move the framer_class structure to be declared at build time
> placing it into read-only memory, instead of having to be dynamically
> allocated at boot time.
> 
> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Signed-off-by: Ricardo B. Marliere <ricardo@marliere.net>

Reviewed-by: Simon Horman <horms@kernel.org>

> ---
>  drivers/net/wan/framer/framer-core.c | 21 +++++++++------------
>  1 file changed, 9 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/net/wan/framer/framer-core.c b/drivers/net/wan/framer/framer-core.c
> index 33b358b99f70..f547c22e26ac 100644
> --- a/drivers/net/wan/framer/framer-core.c
> +++ b/drivers/net/wan/framer/framer-core.c
> @@ -18,7 +18,12 @@
>  #include <linux/regulator/consumer.h>
>  #include <linux/slab.h>
>  
> -static struct class *framer_class;
> +static void framer_release(struct device *dev);
> +static const struct class framer_class = {
> +	.name = "framer",
> +	.dev_release = framer_release,
> +};
> +
>  static DEFINE_MUTEX(framer_provider_mutex);
>  static LIST_HEAD(framer_provider_list);
>  static DEFINE_IDA(framer_ida);
> @@ -627,7 +632,7 @@ struct framer *framer_create(struct device *dev, struct device_node *node,
>  	INIT_DELAYED_WORK(&framer->polling_work, framer_polling_work);
>  	BLOCKING_INIT_NOTIFIER_HEAD(&framer->notifier_list);
>  
> -	framer->dev.class = framer_class;
> +	framer->dev.class = &framer_class;
>  	framer->dev.parent = dev;
>  	framer->dev.of_node = node ? node : dev->of_node;
>  	framer->id = id;
> @@ -741,7 +746,7 @@ struct framer *framer_provider_simple_of_xlate(struct device *dev,
>  	struct class_dev_iter iter;
>  	struct framer *framer;
>  
> -	class_dev_iter_init(&iter, framer_class, NULL, NULL);
> +	class_dev_iter_init(&iter, &framer_class, NULL, NULL);
>  	while ((dev = class_dev_iter_next(&iter))) {
>  		framer = dev_to_framer(dev);
>  		if (args->np != framer->dev.of_node)
> @@ -870,14 +875,6 @@ static void framer_release(struct device *dev)
>  
>  static int __init framer_core_init(void)
>  {
> -	framer_class = class_create("framer");
> -	if (IS_ERR(framer_class)) {
> -		pr_err("failed to create framer class (%pe)\n", framer_class);
> -		return PTR_ERR(framer_class);
> -	}
> -
> -	framer_class->dev_release = framer_release;
> -
> -	return 0;
> +	return class_register(&framer_class);
>  }
>  device_initcall(framer_core_init);
> 
> -- 
> 2.43.0
> 
>