Re: [PATCH] ASoC: soc-pcm: Revert "call snd_soc_component_open/close() once"

[Kai Vehmanen <kai.vehmanen@linux.intel.com>]

Hey,

On Tue, 3 Mar 2020, Kuninori Morimoto wrote:

> Kai Vehmanen wrote:
>> int snd_soc_component_close(struct snd_soc_component *component,
>> »       »       »           struct snd_pcm_substream *substream)
>> {
>> 	/* 
>> 	 * lookup substream from "component->substream_List", 
>> 	 * only call driver->close() if found
>> 	 */
>> ...
>> 
>> ... this is arguably more code, but makes the state created in 
>> snd_soc_component_open() explicit. Upon error in middle of 
>
> But, 1 point I still not yet understand.
> 
> close() will be called 1) when open failed, or, 2) normal close.
> If my understanding was correct, your code is caring that
> 2) normal close() might be called without open().

it also covers case (1) when open fails. So instead of the currently 
merged error case rollback code in soc_pcm_components_open(), we'd just 
call snd_pcm_components_close(substream) directly in case 
of error. With tracking of opened substreams in soc-component.c, close() 
is safe to call also in error case.

But you are right, I don't really see how (2) could be hit, so we are 
essentially talking about how to avoid the <10 lines of rollback code in 
soc_pcm_components_open(). :)

That considered, I'm fine if you can come up with a cleaner version to 
handle just case (1), without tracking substreams. Maybe worth a try and 
if it doesn't work (e.g. with ID/tag), we can look at substream tracking.

Br, Kai