Re: [PATCH 0/3] ASoC: core: Two step component registration

[Cezary Rojewski <cezary.rojewski@intel.com>]

On 2020-07-31 5:58 PM, Lars-Peter Clausen wrote:
> On 7/31/20 5:47 PM, Cezary Rojewski wrote:
>> On 2020-07-31 5:07 PM, Pierre-Louis Bossart wrote:
>>> On 7/31/20 9:41 AM, Cezary Rojewski wrote:
>>>> Provide a mechanism for true two-step component registration. This
>>>> mimics device registration flow where initialization is the first step
>>>> while addition goes as second in line. Drivers may choose to modify
>>>> component's fields before registering component to ASoC subsystem via
>>>> snd_soc_add_component.
>>>
>>> I must admit I don't see where this might be used for Intel 
>>> platforms, we've been happily using snd_soc_register_component() 
>>> without hitting limitations.
>>
>> Patchset targets entire ASoC framework, not Intel catalog. As 
>> _initialize and _add are already in place, having a two-step 
>> registration is cohesive with other "frameworks" e.g. device one.
>>
>> New to ASoC? Trying to learn soc-components? Guess what, 
>> creation/registration procedure is exactly the same as one you're used 
>> to already!
>>
>>> Also the only two uses of snd_soc_add_component() seem mainly driven 
>>> by memory allocation - and avoiding a devm_kzalloc in 
>>> snd_soc_register_component().
>>
>> In general, code quality and improvements to its flow should not 
>> require ton of usages. But hey, you got two already.
>>
>>> Out of curiosity, can you provide an example where this two-step 
>>> would be required or beneficial? Thanks!
>>
>> Overridding component->name which is currently always tied to 
>> fmt_single_name so you may choose a different name than the ->dev one.
> 
> For what it is worth, I think this is a sensible change for the outlined 
> reasons. It's something I've always had in the back of my mind, but 
> there was never enough of a need to actually do it.
> 
> One change I'd like to see is the addition of snd_soc_component_alloc(), 
> which combines the step of kzalloc() and snd_soc_component_init() as 
> these will be done pretty much always in lockstep. And it also matches 
> the APIs that other frameworks offer.
> 
> - Lars
> 

Nice, so it's not just me imagining things : D

In general granular registration is robust and scales well into the 
future. Components functionality will only grow in time so I bet 
usecases don't end on my example.

I'd suggest transition to _alloc/_init/other being separated from this 
patchset - let it serve as a middle step.

Czarek