Re: [PATCH 3/3] soundwire: bus_type: add sdw_master_device support

[Vinod Koul]

On 30-04-20, 02:51, Bard Liao wrote:
> @@ -24,9 +24,14 @@ int sdw_bus_master_add(struct sdw_bus *bus, struct device *parent,
>  	struct sdw_master_prop *prop = NULL;
>  	int ret;
>  
> -	if (!bus->dev) {
> -		pr_err("SoundWire bus has no device\n");
> -		return -ENODEV;

This check is removed and not moved into sdw_master_device_add() either,
can you add here or in patch 1 and keep checking the parent device please

> +int sdw_master_device_add(struct sdw_bus *bus, struct device *parent,
> +			  struct fwnode_handle *fwnode)
> +{
> +	struct sdw_master_device *md;
> +	int ret;
> +
> +	if (!bus)
> +		return -EINVAL;
> +
> +	/*
> +	 * Unlike traditional devices, there's no allocation here since the
> +	 * sdw_master_device is embedded in the bus structure.
> +	 */

Looking at this and empty sdw_master_device_release() above, makes me
wonder if it is a wise move? Should we rather allocate the
sdw_master_device() and then free that up in sdw_master_device_release()
or it is really overkill given that this is called when we remove the
sdw_bus instance as well...

> +	md = &bus->md;
> +	md->dev.bus = &sdw_bus_type;
> +	md->dev.type = &sdw_master_type;
> +	md->dev.parent = parent;
> +	md->dev.of_node = parent->of_node;
> +	md->dev.fwnode = fwnode;
> +	md->dev.dma_mask = parent->dma_mask;
> +
> +	dev_set_name(&md->dev, "sdw-master-%d", bus->link_id);

This give nice sdw-master-0. In DT this comes from reg property. I dont
seem to recall if the ACPI/Disco spec treats link_id as unique across
the system, can you check that please, if not we would need to update
this.

-- 
~Vinod