Re: [PATCH 0/3] ASoC: grace time for DPCM cleanup

[Jerome Brunet <jbrunet@xxxxxxxxxxxx>]

On Thu 09 May 2024 at 05:50, Kuninori Morimoto <kuninori.morimoto.gx@xxxxxxxxxxx> wrote:

> Hi Jerome
>
> I need your help
>
>> > I have tested this series on an Amlogic device (vim3l)
>> > This brings warnings for cases which are perfectly fine.
>> > 
>> > For example, one of the DPCM backends is the TDM interface. This
>> > interface is capable of both playback and capture. It can be associated
>> > with any i2s/TDM codec.
>> > 
>> > The codec may do playback and capture too, but it
>> > may also do a single direction. Then usual example is the hdmi codec
>> > which does playback only.
>> > 
>> > In this case I get:
>> >  axg-sound-card sound: CPU capture is available but Codec capture is not (be.dai-link-6) Please update Codec driver
>> > 
>> > I don't think this is right.
>> 
>> Hmm..., I'm confusing
>> Does it mean you want to use "playback only" on it ?
>> If so, did you get below warning too ?
>> 	 "both playback/capture are available, but not using playback_only flag (%s)\n",
>>

I've checked. No such trace, no.

>> If not, can you please fill below ?
>> 
>> Card
>> 	dpcm_playback = (0 or 1)
>> 	dpcm_capture  = (0 or 1)
>> 	playback_only = (0 or 1)
>> 	capture_only  = (0 or 1)
>> BE.CPU
>> 	playback = (available, not available)
>> 	capture  = (available, not available)
>> BE.Codec
>> 	playback = (available, not available)
>> 	capture  = (available, not available)
>> Expect
>> 	playback = (available, not available)
>> 	capture  = (available, not available)

I'm not too sure I undestand this. I'll try to illustrate the case
raising the warning as precisely as possible bellow

>
> I need feedback from you, it is still not clear for me.

Sorry. There are some national holidays in France. I'm not spending much
time near the keyboard ATM

> But I noticed that we want to update below. I'm happy if it can solve your
> issue.
>
> -	if (has_playback && !has_playback_both)
> +	if (has_playback && !has_playback_both && !dai_link->capture_only)
> 		dev_warn(rtd->card->dev, ...)
>
> -	if (has_capture && !has_capture_both)
> +	if (has_capture && !has_capture_both && !dai_link->playback_only)
> 		dev_warn(rtd->card->dev, ...)
>

Honestly I'm a bit lost in all these flag :/

Some for BE error reported here is the full picture

     PCM
 =====|=====
      V
    --------
    |CPU FE| This CPU (FIFO) does Playback only. 
    --------
      |  Because of the CPU, link a playback only one
      V
    ----------
    |Codec FE| Using Dummy here
    ----------
      |
      V
    ~~~~~~~~~~
    |Routing |
    ~~~~~~~~~~
      ^
      |
      V
    --------
    |CPU BE|  This is the TDM interface. Capable of both Playback and
    --------  Capture. Through routing it can be connected to Playback
      ^       and/or Capture FE CPUs.
      |
      |
      V
    -------------
    |BE Codec(s)| Possibly N codecs, supporting both direction, or a
    ------------- Single one, or one direction each. In this particular case
      |           it is Playback only C2C.
      |
 ---- V ------------------ From Here, it is specific to HDMI -------------
    ~~~~~~~~~~~~~
    |C2C Routing| SoC has routing has mux between the different TDM
    ~~~~~~~~~~~~~ interfaces and the HDMI controller
      |
      |
      V
    ---------
    |C2C CPU|     This is a playback only CPU for HDMI
    ---------
      |
      V
    -----------
    |HDMI Codec|  The usual HDMI codec, playback only
    -----------

Better picture are available in the SoC doc.
There is publicly available datasheet here [1]

Audio paths are displayed in Section 9, page 807, Figure 9-1.
A TDM interface in this figure is combination of a TDMOUT and a TDMIN
(axg-tdm-formatter.c). The axg-tdm-interface.c joins them because they
use the same pads and clocks.

[1]: https://dl.khadas.com/products/vim3l/datasheet/s905d3_datasheet_0.2_wesion.pdf

>
>
> Thank you for your help !!
>
> Best regards
> ---
> Renesas Electronics
> Ph.D. Kuninori Morimoto


-- 
Jerome