Re: [PATCH v2 1/3] ASoC: soc-acpi: add comp_ids field for machine driver matching

[Cezary Rojewski]

On 2021-10-07 3:35 PM, Brent Lu wrote:

...

>   
> +static bool snd_soc_acpi_id_present(struct snd_soc_acpi_mach *machine)
> +{
> +	struct snd_soc_acpi_codecs *comp_ids = machine->comp_ids;
> +	int i;
> +
> +	if (machine->id[0]) {
> +		if (acpi_dev_present(machine->id, NULL, -1))
> +			return true;
> +	}
> +
> +	if (comp_ids) {
> +		for (i = 0; i < comp_ids->num_codecs; i++) {
> +			if (acpi_dev_present(comp_ids->codecs[i], NULL, -1))
> +				return true;
> +		}
> +	}
> +
> +	return false;
> +}

In cover letter you mention:
"- can use 'comp_ids' field alone to enumerate driver"

which leads me to an opinion that field 'id' should be removed, 
entirely. With 'comp_ids' added, 'id' is basically rendered 
optional/redundant.

> +
>   struct snd_soc_acpi_mach *
>   snd_soc_acpi_find_machine(struct snd_soc_acpi_mach *machines)
>   {
>   	struct snd_soc_acpi_mach *mach;
>   	struct snd_soc_acpi_mach *mach_alt;
>   
> -	for (mach = machines; mach->id[0]; mach++) {
> -		if (acpi_dev_present(mach->id, NULL, -1)) {
> +	for (mach = machines; mach->id[0] || mach->comp_ids; mach++) {

Such loops are hard to maintain i.e. 'comp_ids' acts here like a flex 
array that follows 'id'. Removal of 'id' field and streamlining code to 
only use 'comp_ids' should make this loop more intuitive.

> +		if (snd_soc_acpi_id_present(mach)) {
>   			if (mach->machine_quirk) {
>   				mach_alt = mach->machine_quirk(mach);
>   				if (!mach_alt)