[alsa-devel] [PATCH 06/14] soundwire: add support for sdw_slave_type

[Cezary Rojewski]

On 2019-10-23 23:28, Pierre-Louis Bossart wrote:
> diff --git a/drivers/soundwire/bus_type.c b/drivers/soundwire/bus_type.c
> index 9a0fd3ee1014..5df095f4e12f 100644
> --- a/drivers/soundwire/bus_type.c
> +++ b/drivers/soundwire/bus_type.c
> @@ -49,9 +49,16 @@ int sdw_slave_modalias(const struct sdw_slave *slave, char *buf, size_t size)
>   
>   static int sdw_uevent(struct device *dev, struct kobj_uevent_env *env)
>   {
> -	struct sdw_slave *slave = to_sdw_slave_device(dev);
> +	struct sdw_slave *slave;
>   	char modalias[32];
>   
> +	if (is_sdw_slave(dev)) {
> +		slave = to_sdw_slave_device(dev);
> +	} else {
> +		dev_warn(dev, "uevent for unknown Soundwire type\n");
> +		return -EINVAL;
> +	}
> +
>   	sdw_slave_modalias(slave, modalias, sizeof(modalias));
>   
>   	if (add_uevent_var(env, "MODALIAS=%s", modalias))

Positive evaluation of is_sdw_slave() check is required for function to 
continue, thus you might as well do:

if (!is_sdw_slave(dev)) {
	dev_warn();
	return -EINVAL;
}

slave = to_sdw_slave_device(dev);
(...)

Czarek