Re: [PATCH v4 2/3] ASoC: Add multiple CPU DAI support for PCM ops

[Shreyas NC <shreyas.nc@intel.com>]

> > @@ -313,13 +333,18 @@ static int soc_pcm_params_symmetry(struct snd_pcm_substream *substream,
> >  static bool soc_pcm_has_symmetry(struct snd_pcm_substream *substream)
> >  {
> >  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
> > -	struct snd_soc_dai_driver *cpu_driver = rtd->cpu_dai->driver;
> >  	struct snd_soc_dai_link *link = rtd->dai_link;
> > -	unsigned int symmetry, i;
> > +	unsigned int symmetry = 0, i;
> 
> No need to init this to zero you are explicitly setting it
> straight after.
> 

yes, will fix it.

> > @@ -427,30 +466,55 @@ static void soc_pcm_init_runtime_hw(struct snd_pcm_substream *substream)
> >  		rates = snd_pcm_rate_mask_intersect(codec_stream->rates, rates);
> >  	}
> >  
> > +	for (i = 0; i < rtd->num_cpu_dai; i++) {
> > +		cpu_dai_drv = rtd->cpu_dais[i]->driver;
> > +
> > +		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
> > +			cpu_stream = &cpu_dai_drv->playback;
> > +		else
> > +			cpu_stream = &cpu_dai_drv->capture;
> > +
> > +		cpu_chan_min = max(hw->channels_min,
> > +					cpu_stream->channels_min);
> > +		cpu_chan_max = min(hw->channels_max,
> > +					cpu_stream->channels_max);
> 
> At the end of the loop cpu_chan_min and cpu_chan_max will only
> have considered the channels_min/max from the last cpu DAI, is
> that the behaviour you wanted?
> 
> > +
> > +		if (hw->formats)
> > +			hw->formats &= cpu_stream->formats;
> > +		else
> > +			hw->formats = cpu_stream->formats;
> > +
> > +		cpu_rates = snd_pcm_rate_mask_intersect(cpu_rates,
> > +						cpu_stream->rates);
> > +
> > +		cpu_rate_min = max(hw->rate_min, cpu_stream->rate_min);
> > +		cpu_rate_max = min_not_zero(hw->rate_max, cpu_stream->rate_max);
> 
> Same here with cpu_rate_min and cpu_rate_max all the first n-1 CPU
> DAIs are ignored and only the last DAI is considered.
> 

This is not intended, will fix this and the previous comment.

> > @@ -1162,7 +1292,7 @@ static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
> >  	struct snd_soc_pcm_runtime *rtd = substream->private_data;
> >  	struct snd_soc_component *component;
> >  	struct snd_soc_rtdcom_list *rtdcom;
> > -	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
> > +	struct snd_soc_dai *cpu_dai;
> >  	struct snd_soc_dai *codec_dai;
> >  	struct snd_pcm_runtime *runtime = substream->runtime;
> >  	snd_pcm_uframes_t offset = 0;
> > @@ -1182,8 +1312,12 @@ static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
> >  		break;
> >  	}
> >  
> > -	if (cpu_dai->driver->ops->delay)
> > -		delay += cpu_dai->driver->ops->delay(substream, cpu_dai);
> > +	for (i = 0; i < rtd->num_cpu_dai; i++) {
> > +		cpu_dai = rtd->cpu_dais[i];
> > +		if (cpu_dai->driver->ops->delay)
> > +			delay += cpu_dai->driver->ops->delay(substream,
> > +								cpu_dai);
> > +	}
> 
> Should we be adding these delays? Wouldn't it be better to use
> the max CPU DAI delay as we do for the CODECs, or is there a
> reason these are additive?
> 

Yes, this has to be fixed. I thought I had fixed this in the earlier
reviews :(

> >  			if (!be->dai_link->no_pcm)
> >  				continue;
> >  
> > -			dev_dbg(card->dev, "ASoC: try BE %s\n",
> > -				be->cpu_dai->capture_widget ?
> > -				be->cpu_dai->capture_widget->name : "(not set)");
> > +			for (i = 0; i < be->num_cpu_dai; i++) {
> > +				struct snd_soc_dai *cpu_dai = be->cpu_dais[i];
> >  
> > -			if (be->cpu_dai->capture_widget == widget)
> > -				return be;
> > +				dev_dbg(card->dev, "ASoC: try BE %s\n",
> > +					cpu_dai->capture_widget ?
> > +					cpu_dai->capture_widget->name : "(not set)");
> > +
> > +				if (cpu_dai->capture_widget == widget)
> > +					return be;
> > +			}
> >  
> >  			for (i = 0; i < be->num_codecs; i++) {
> >  				struct snd_soc_dai *dai = be->codec_dais[i];
> 
> I still think you need to get Liam or someone to review this DPCM
> stuff. Multi-CPU DAIs feels like it could be a tricky thing to
> merge with DPCM and I am not sure I am confident enough in me
> reviewing it right.
> 

Sure, makes sense :)

Thanks for the review!

--Shreyas

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