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 ?

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