[alsa-devel] Converting a non BE to BE inside soc_check_tplg_fes

[Daniel Baluta]

Hi Liam,

I continued with the investigation and found really interesting
things. See below:

On Tue, Nov 26, 2019 at 5:32 PM Liam Girdwood
<liam.r.girdwood at linux.intel.com> wrote:
>
> On Mon, 2019-11-25 at 18:45 +0200, Daniel Baluta wrote:
> > Hi all,
> >
> > I am trying how a non-BE link is converted to a BE link
> > inside soc_check_tplg_fes.
> >
> > soc_check_tplg_fes
> > => for all components that have ignore_machine setup to card name
> >      => dai_link->platforms->name = component->name;
> >      => dai_link->no_pcm = 1;
> >
> > But the thing is that the link is a true non-DPCM link, than fields
> > like dpcm_playback/dpcm_capture are not set and playback/record
> > substreams are no created.
>
> These fields should be being populated by topology since they are
> runtime configuration on a non DPCM PCM device.
>
> >
> > The question is: is this supposed to be working with non-DPCM links?
>
> Yes, it "should do" and did when I last tested - there were some non
> DPCM Intel machine drivers that needed to work (grep -L no_pcm
> sound/soc/intel/boards/*.c), but I am not as up to date as other on the
> SOF driver core now. So if it's not working, it could be a regression
> (as these non DPCM boards are not used now IIRC).

Did you somehow tested it between March 27 and April 19. I think
in this window span it should have worked.

The history is like this:

commit 45f8cb57da0d7a9ead4b39d7f5def333a5b0c08b
Author: Liam Girdwood <liam.r.girdwood at linux.intel.com>
Date:   Tue Mar 27 14:30:40 2018 +0100

    ASoC: core: Allow topology to override machine driver FE DAI link config.


This patch introduced the overriding FE capability. This patch
contains something like this;

+                       /* convert non BE into BE */
+                       dai_link->no_pcm = 1;
+                       dai_link->dpcm_playback = 1;
+                       dai_link->dpcm_capture = 1;

then the patch got reverted by:

commit 291bfb928863d496e25c785e132a8fbfb32341a8
Author: Mark Brown <broonie at kernel.org>
Date:   Thu Apr 19 12:14:10 2018 +0100

    ASoC: topology: Revert recent changes while boot errors are investigated

and then when it got reinstantiated with:

commit a655de808cbde6c58b3298e704d786b53f59fb5d
Author: Liam Girdwood <liam.r.girdwood at linux.intel.com>
Date:   Mon Jul 2 16:59:54 2018 +0100

    ASoC: core: Allow topology to override machine driver FE DAI link config.

it does have some changes one of them is that
dpcm_playback/dpcm_capture are no longer
set.

+                       /* convert non BE into BE */
+                       dai_link->no_pcm = 1;

Do you remember what was the root cause that caused the crash?

I would like to re-add the following lines:

+                       dai_link->dpcm_playback = 1;
+                       dai_link->dpcm_capture = 1;

With these two lines added back the non-DPCM link works well for me.

Thanks a lot for your help.

Can someone at Intel test following machine drivers for SOF:

sound/soc/intel/boards/byt-max98090.c
sound/soc/intel/boards/byt-rt5640.c

I would expect them not to work for SOF case.