Re: [PATCH 15/15] ASoC: soc-pcm: indicate warning if DPCM BE Codec has no settings

[Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx>]

Hi Jerome

Thank you for your feedback

> 	DPCM
> 		[CPU/xxxx]-[xxxx/Codec]
> 		^^^^                   (A)
(snip)
> 	DPCM
> 		[CPU/xxxx]-[xxxx/Codec]
> 		^^^^^^^^^   ^^^^^^^^^^ (B)
(snip)
> > 	if ((dai_link->no_pcm) &&
>                          ^ Actually my comment applies to all links, DPCM backend or not
(snip)
> A codec that does not support playback and does not support capture does
> not support much, does it ? ;)

Unfortunately, some codec which is used on DPCM BE doesn't have
.channels_min = 1 settings which is used on snd_soc_dai_stream_valid().
At least Intel is using it. For both Playback/Capture.

But it *was* no problem, because (A) part was not checked before.

Because of this background, [01/15] patch is using dummy Codec
to avoid (B) check.

[15/15] patch will indicate WARNING for such codec driver
instead of just avoiding.
At least, below are the drivers. It is mentioned in git-log.

	sound/soc/codecs/hda.c
	sound/pci/hda/patch_hdmi.c

dai_link->no_pcm only is OK I think, because it needs to keep
compatibility and try to indicates warning for (A) and/or (B) part.
If such things happen on FE side, it is just error, not warning.

>           (!cpu_play_t && !codec_capture_t)) { 
>
> Then at first glance, maybe ... CPU and codec seem to exclude each other but
> that will only work as long as DCPM is limited to a single CPU per link.

Hmm ?? I'm confusing
Did you copy-and-paste miss ??
I have never indicate this pair

+ I have indicated before
- I have not

+	( cpu_capture_t && !codec_capture_t)	// in [15/15] patch
+	(!codec_play_t  && !codec_capture_t)	// in previous mail
-	(!cpu_play_t    && !codec_capture_t)

and I'm sorry but I can't understand what you want to tell me.
Do you mean Multi-CPU case ?
If you can indicate Image or code, it can more help me.

Thank you for your help !!

Best regards
---
Renesas Electronics
Ph.D. Kuninori Morimoto