Re: [PATCH v4 15/23] ASoC: soc-core: Identify 'no_pcm' DAI links for DPCM

From: Sameer Pujar
Date: Tue Jun 30 2020 - 04:04:02 EST




On 6/30/2020 11:37 AM, Kuninori Morimoto wrote:
External email: Use caution opening links or attachments


Hi Sameer

PCM devices are created for dai links with 'no-pcm' flag as '0'.
Such DAI links have CPU component which implement pcm_construct()
and pcm_destruct() callbacks. Based on this, current patch exposes
a helper function to identify such components and populate 'no_pcm'
flag for DPCM DAI link.

This helps to have BE<->BE component links where PCM devices need
not be created for CPU components involved in the links.

Signed-off-by: Sameer Pujar <spujar@xxxxxxxxxx>
---
(snip)
+bool soc_component_is_pcm(struct snd_soc_dai_link_component *dlc)
+{
+ struct snd_soc_component *component;
+ struct snd_soc_dai *dai;
+
+ for_each_component(component) {
+ if (!component->driver)
+ continue;
+
+ for_each_component_dais(component, dai) {
+ if (!dai->name || !dlc->dai_name)
+ continue;
+
+ if (strcmp(dai->name, dlc->dai_name))
+ continue;
+
+ if (component->driver->pcm_construct)
+ return true;
+ }
+ }
+
+ return false;
+}
At least my CPU driver doesn't use component:pcm_construct
but is using DAI:pcm_new for some reasons.
I'm not sure checking DAI:pcm here is enough, or not...

OK. If adding DAI:pcm_new above here is not sufficient, then a flag can be used to describe FE component? or is there a better alternative?

Thank you for your help !!

Best regards
---
Kuninori Morimoto