Re: [alsa-devel] [PATCH] ASoC: soc-core: Set dpcm_playback / dpcm_capture

[Pierre-Louis Bossart]

On 12/4/19 5:29 PM, Sridharan, Ranjani wrote:
> On Wed, Dec 4, 2019 at 7:16 AM Daniel Baluta <daniel.baluta@xxxxxxx> wrote:
>
> > When converting a normal link to a DPCM link we need
> > to set dpcm_playback / dpcm_capture otherwise playback/capture
> > streams will not be created resulting in errors like this:
> >
> > [   36.039111]  sai1-wm8960-hifi: ASoC: no backend playback stream
> >
> > Fixes: a655de808cbde ("ASoC: core: Allow topology to override machine
> > driver FE DAI link config")
> > Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxx>
> > ---
> >   sound/soc/soc-core.c | 2 ++
> >   1 file changed, 2 insertions(+)
> >
> > diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
> > index 977a7bfad519..f89cf9d0860c 100644
> > --- a/sound/soc/soc-core.c
> > +++ b/sound/soc/soc-core.c
> > @@ -1872,6 +1872,8 @@ static void soc_check_tplg_fes(struct snd_soc_card
> > *card)
> >
> >                          /* convert non BE into BE */
> >                          dai_link->no_pcm = 1;
> > +                       dai_link->dpcm_playback = 1;
> > +                       dai_link->dpcm_capture = 1;
> Hi Daniel,
>
> Typically, for Intel platforms, this information comes from the machine
> driver and there are some DAI links that have either playback or capture
> set. But this change would set both for all DAI links.
> Not sure if this is the right thing to do.

I am with Ranjani, I don't get why we'd set the full-duplex mode by 
default. but to be honest I never quite understood what this code is 
supposed to do...