Re: [PATCH v6 02/14] ASoC: sun4i-i2s: Change set_chan_cfg() params

["Clément Péron" <peron.clem@gmail.com>]

Hi Maxime,

On Mon, 5 Oct 2020 at 14:13, Maxime Ripard <maxime@cerno.tech> wrote:
>
> On Sat, Oct 03, 2020 at 04:19:38PM +0200, Clément Péron wrote:
> > As slots and slot_width can be set manually using set_tdm().
> > These values are then kept in sun4i_i2s struct.
> > So we need to check if these values are setted or not
> > in the struct.
> >
> > Avoid to check for this logic in set_chan_cfg(). This will
> > duplicate the same check instead pass the required values
> > as params to set_chan_cfg().
> >
> > This will also avoid a bug when we will enable 20/24bits support,
> > i2s->slot_width is not actually used in the lrck_period computation.
> >
> > Suggested-by: Samuel Holland <samuel@sholland.org>
> > Signed-off-by: Clément Péron <peron.clem@gmail.com>
> > ---
> >  sound/soc/sunxi/sun4i-i2s.c | 36 ++++++++++++++----------------------
> >  1 file changed, 14 insertions(+), 22 deletions(-)
> >
> > diff --git a/sound/soc/sunxi/sun4i-i2s.c b/sound/soc/sunxi/sun4i-i2s.c
> > index c5ccd423e6d3..1f577dbc20a6 100644
> > --- a/sound/soc/sunxi/sun4i-i2s.c
> > +++ b/sound/soc/sunxi/sun4i-i2s.c
> > @@ -177,8 +177,9 @@ struct sun4i_i2s_quirks {
> >       unsigned long (*get_bclk_parent_rate)(const struct sun4i_i2s *);
> >       s8      (*get_sr)(const struct sun4i_i2s *, int);
> >       s8      (*get_wss)(const struct sun4i_i2s *, int);
> > -     int     (*set_chan_cfg)(const struct sun4i_i2s *,
> > -                             const struct snd_pcm_hw_params *);
> > +     int     (*set_chan_cfg)(const struct sun4i_i2s *i2s,
> > +                             unsigned int channels,  unsigned int slots,
> > +                             unsigned int slot_width);
> >       int     (*set_fmt)(const struct sun4i_i2s *, unsigned int);
> >  };
> >
> > @@ -414,10 +415,9 @@ static s8 sun8i_i2s_get_sr_wss(const struct sun4i_i2s *i2s, int width)
> >  }
> >
> >  static int sun4i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> > -                               const struct snd_pcm_hw_params *params)
> > +                               unsigned int channels, unsigned int slots,
> > +                               unsigned int slot_width)
> >  {
> > -     unsigned int channels = params_channels(params);
> > -
> >       /* Map the channels for playback and capture */
> >       regmap_write(i2s->regmap, SUN4I_I2S_TX_CHAN_MAP_REG, 0x76543210);
> >       regmap_write(i2s->regmap, SUN4I_I2S_RX_CHAN_MAP_REG, 0x00003210);
> > @@ -434,15 +434,11 @@ static int sun4i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> >  }
> >
> >  static int sun8i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> > -                               const struct snd_pcm_hw_params *params)
> > +                               unsigned int channels, unsigned int slots,
> > +                               unsigned int slot_width)
> >  {
> > -     unsigned int channels = params_channels(params);
> > -     unsigned int slots = channels;
> >       unsigned int lrck_period;
> >
> > -     if (i2s->slots)
> > -             slots = i2s->slots;
> > -
> >       /* Map the channels for playback and capture */
> >       regmap_write(i2s->regmap, SUN8I_I2S_TX_CHAN_MAP_REG, 0x76543210);
> >       regmap_write(i2s->regmap, SUN8I_I2S_RX_CHAN_MAP_REG, 0x76543210);
> > @@ -467,11 +463,11 @@ static int sun8i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> >       case SND_SOC_DAIFMT_DSP_B:
> >       case SND_SOC_DAIFMT_LEFT_J:
> >       case SND_SOC_DAIFMT_RIGHT_J:
> > -             lrck_period = params_physical_width(params) * slots;
> > +             lrck_period = slot_width * slots;
> >               break;
> >
> >       case SND_SOC_DAIFMT_I2S:
> > -             lrck_period = params_physical_width(params);
> > +             lrck_period = slot_width;
> >               break;
> >
> >       default:
> > @@ -490,15 +486,11 @@ static int sun8i_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> >  }
> >
> >  static int sun50i_h6_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> > -                                   const struct snd_pcm_hw_params *params)
> > +                                   unsigned int channels, unsigned int slots,
> > +                                   unsigned int slot_width)
> >  {
> > -     unsigned int channels = params_channels(params);
> > -     unsigned int slots = channels;
> >       unsigned int lrck_period;
> >
> > -     if (i2s->slots)
> > -             slots = i2s->slots;
> > -
> >       /* Map the channels for playback and capture */
> >       regmap_write(i2s->regmap, SUN50I_H6_I2S_TX_CHAN_MAP0_REG, 0xFEDCBA98);
> >       regmap_write(i2s->regmap, SUN50I_H6_I2S_TX_CHAN_MAP1_REG, 0x76543210);
> > @@ -525,11 +517,11 @@ static int sun50i_h6_i2s_set_chan_cfg(const struct sun4i_i2s *i2s,
> >       case SND_SOC_DAIFMT_DSP_B:
> >       case SND_SOC_DAIFMT_LEFT_J:
> >       case SND_SOC_DAIFMT_RIGHT_J:
> > -             lrck_period = params_physical_width(params) * slots;
> > +             lrck_period = slot_width * slots;
> >               break;
> >
> >       case SND_SOC_DAIFMT_I2S:
> > -             lrck_period = params_physical_width(params);
> > +             lrck_period = slot_width;
> >               break;
> >
> >       default:
> > @@ -565,7 +557,7 @@ static int sun4i_i2s_hw_params(struct snd_pcm_substream *substream,
> >       if (i2s->slot_width)
> >               slot_width = i2s->slot_width;
> >
> > -     ret = i2s->variant->set_chan_cfg(i2s, params);
> > +     ret = i2s->variant->set_chan_cfg(i2s, channels, slots, slot_width);
>
> Isn't slots and slot_width set to 0 here ?

No, there is still a check before calling the set_cfg function.

  unsigned int slot_width = params_physical_width(params);
  unsigned int channels = params_channels(params);
  unsigned int slots = channels;

  if (i2s->slots)
  slots = i2s->slots;

  if (i2s->slot_width)
  slot_width = i2s->slot_width;

ret = i2s->variant->set_chan_cfg(i2s, channels, slots, slot_width);

So slot_width will be equal to params_physical_width(params);
like before

Clement

>
> And therefore, wouldn't we set lrck_period to 0 if we're using any
> format but I2S?
>
> More importantly, I'm not really convinced this needs to be done, and it
> introduces some side effects that are not explained.
>
> Maxime