Re: [PATCH] ASoC: fsl_sai: Set SAI Channel Mode to Output Mode

From: Shengjiu Wang
Date: Thu Sep 03 2020 - 01:38:49 EST


On Thu, Sep 3, 2020 at 11:42 AM Nicolin Chen <nicoleotsuka@xxxxxxxxx> wrote:
>
> On Thu, Sep 03, 2020 at 11:09:15AM +0800, Shengjiu Wang wrote:
> > Transmit data pins will output zero when slots are masked or channels
> > are disabled. In CHMOD TDM mode, transmit data pins are tri-stated when
> > slots are masked or channels are disabled. When data pins are tri-stated,
> > there is noise on some channels when FS clock value is high and data is
> > read while fsclk is transitioning from high to low.
> >
> > Signed-off-by: Cosmin-Gabriel Samoila <cosmin.samoila@xxxxxxx>
> > Signed-off-by: Shengjiu Wang <shengjiu.wang@xxxxxxx>
>
> Acked-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
>
> Though one nit inline:
>
> > ---
> > sound/soc/fsl/fsl_sai.c | 12 ++++++++++--
> > sound/soc/fsl/fsl_sai.h | 2 ++
> > 2 files changed, 12 insertions(+), 2 deletions(-)
> >
> > diff --git a/sound/soc/fsl/fsl_sai.c b/sound/soc/fsl/fsl_sai.c
> > index 62c5fdb678fc..33b194a5c1dc 100644
> > --- a/sound/soc/fsl/fsl_sai.c
> > +++ b/sound/soc/fsl/fsl_sai.c
> > @@ -486,6 +486,12 @@ static int fsl_sai_hw_params(struct snd_pcm_substream *substream,
> >
> > val_cr4 |= FSL_SAI_CR4_FRSZ(slots);
> >
> > + /* Output Mode - data pins transmit 0 when slots are masked
> > + * or channels are disabled
> > + */
>
> Coding style for multi-line comments. Yet, probably can simplify?
>
> /* Set to output mode to avoid tri-stated data pins */
Ok, will update in v2.

best regards
wang shengjiu