[alsa-devel] Counting links in simple-card

[Daniel Baluta]

On Wed, Oct 9, 2019 at 3:18 AM Kuninori Morimoto
<kuninori.morimoto.gx at renesas.com> wrote:
>
>
> Hi Daniel
>
> > >      * ex1)
> > >      * CPU0 --- Codec0
> > >      * CPU1 --- Codec1
> > >      * CPU2 -----/
> > >      * CPU3 --- Codec2
> > >      *
> > >      *    => 5 links = 2xCPU-Codec + 2xCPU-dummy + 1xdummy-Codec
> > >      *    => 7 DAIs  = 4xCPU + 3xCodec
> > >      *    => 1 ccnf  = 1xdummy-Codec
> > >
> > >
> > > So, I don't understand exactly how did you get the formula for links. AFAICT
> > > there should be 3 x CPU-Codec + 1 x CPU-dummy.
>
> CPU1/CPU2 and Codec1 are using DPCM.
> Thus, it is...
>
>  2xCPU-Codec:
>         CPU0 - Codec0
>         CPU3 - Codec2
>
>  2xCPU-dummy:
>         CPU1 - dummy
>         CPU2 - dummy
>
>  1xdummy-Codec:
>         dummy - Codec1
>
>
> > Also, I wonder how can i use simple-card to create just a backend link
> > CPU-dummy + Codec :).
> >
> > Is this supported?
>
> Do you mean CPU-dummy + dummy-Codec ?
> But anyway, simple-card/audio-graph DPCM support is very limited.
> Unfortunately it doesn't have flexibility...


Yes, exactly. I need 1 DAI link with 1 FE + 1 BE for DSP / SOF  usecase.