[PATCH] ASoC: mediatek: mt8195: Re-add codec entry for ETDM1_OUT_BE dai link

[Chen-Yu Tsai]

On Fri, Jun 21, 2024 at 12:28 PM Chen-Yu Tsai <wenst at chromium.org> wrote:
>
> On Thu, Jun 20, 2024 at 6:27 PM AngeloGioacchino Del Regno
> <angelogioacchino.delregno at collabora.com> wrote:
> >
> > Il 20/06/24 11:25, Chen-Yu Tsai ha scritto:
> > > This partially reverts commit e70b8dd26711704b1ff1f1b4eb3d048ba69e29da.
> > >
> > > Said commit removes the codec entry for the ETDM1_OUT_BE dai link for
> > > some reason. This does not have the intended effect, as the remaining
> > > DAILINK_COMP_ARRAY(COMP_EMPTY()) platform entry becomes the codec
> > > entry, and the platform entry is completely gone.
> > >
> > > This causes in a KASAN out-of-bounds warning in mtk_soundcard_common_probe()
> > > in sound/soc/mediatek/common/mtk-soundcard-driver.c:
> > >
> > >       for_each_card_prelinks(card, i, dai_link) {
> > >               if (adsp_node && !strncmp(dai_link->name, "AFE_SOF", strlen("AFE_SOF")))
> > >                       dai_link->platforms->of_node = adsp_node;
> > >               else if (!dai_link->platforms->name && !dai_link->platforms->of_node)
> > >                       dai_link->platforms->of_node = platform_node;
> > >       }
> > >
> > > where the code expects the platforms array to have space for at least one entry.
> > >
> > > Re-add the entry so that dai_link->platforms has space.
> > >
> >
> > Ok, but wait a minute... the commit that you're pointing at in the Fixes tag is
> > a commit that fixes a problem identified in commit
> >
> > 13f58267cda3 ("ASoC: soc.h: don't create dummy Component via COMP_DUMMY()")
> >
> > to keep it short, after that one, without removing the COMP_DUMMY(), the audio
> > was broken in .. some way, I don't currently remember specifically what was
> > happening, but I had no sound at all.

In a way, by removing COMP_DUMMY() completely, you effectively replaced it
with COMP_EMPTY() (from the platform entry), while the platform entry
effectively became COMP_DUMMY() (which is equal to a completely empty
entry).

> Right. But this adds back "COMP_EMPTY()", not COMP_DUMMY().
>
> I guess I shouldn't say this is a partial revert.
>
> After painstakingly messing with the mixer controls, I tested all three
> audio paths (speaker, headphone, DP) and they all work correctly.
>
> I'll send a v2 updating the commit message.
>
> ChenYu
>
> > If the problem is not showing up anymore, backporting this commit to the kernels
> > kernels affected by the issue that I solved... will break sound!
> >
> > So... well.. that's the "some reason".... :-)
> >
> > Cheers,
> > Angelo
> >
> > > Fixes: e70b8dd26711 ("ASoC: mediatek: mt8195: Remove afe-dai component and rework codec link")
> > > Signed-off-by: Chen-Yu Tsai <wenst at chromium.org>
> > > ---
> > >   sound/soc/mediatek/mt8195/mt8195-mt6359.c | 1 +
> > >   1 file changed, 1 insertion(+)
> > >
> > > diff --git a/sound/soc/mediatek/mt8195/mt8195-mt6359.c b/sound/soc/mediatek/mt8195/mt8195-mt6359.c
> > > index ca8751190520..2832ef78eaed 100644
> > > --- a/sound/soc/mediatek/mt8195/mt8195-mt6359.c
> > > +++ b/sound/soc/mediatek/mt8195/mt8195-mt6359.c
> > > @@ -827,6 +827,7 @@ SND_SOC_DAILINK_DEFS(ETDM2_IN_BE,
> > >
> > >   SND_SOC_DAILINK_DEFS(ETDM1_OUT_BE,
> > >                    DAILINK_COMP_ARRAY(COMP_CPU("ETDM1_OUT")),
> > > +                  DAILINK_COMP_ARRAY(COMP_EMPTY()),
> > >                    DAILINK_COMP_ARRAY(COMP_EMPTY()));
> > >
> > >   SND_SOC_DAILINK_DEFS(ETDM2_OUT_BE,
> >