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

On Tue, May 08, 2018 at 04:15:34PM +0530, Shreyas NC wrote:

Add support in PCM operations to invoke multiple cpu dais as we do for multiple codec dais. Also the symmetry calculations are updated to reflect multiple cpu dais.

Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Shreyas NC shreyas.nc@intel.com

---

sound/soc/soc-pcm.c | 487 +++++++++++++++++++++++++++++++++++----------------- 1 file changed, 326 insertions(+), 161 deletions(-)

Getting down to the last few comments from me :-)

@@ -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.

• symmetry = cpu_driver->symmetric_rates || link->symmetric_rates ||

• cpu_driver->symmetric_channels || link->symmetric_channels ||
  

• cpu_driver->symmetric_samplebits || link->symmetric_samplebits;
  

• symmetry = link->symmetric_rates || link->symmetric_channels ||

• 	link->symmetric_samplebits;
  

@@ -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.

@@ -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?

for (i = 0; i < rtd->num_codecs; i++) { codec_dai = rtd->codec_dais[i]; @@ -1306,12 +1440,16 @@ static struct snd_soc_pcm_runtime *dpcm_get_be(struct snd_soc_card *card, if (!be->dai_link->no_pcm) continue;

• 	dev_dbg(card->dev, "ASoC: try BE : %s\n",
  

• 		be->cpu_dai->playback_widget ?
  

• 		be->cpu_dai->playback_widget->name : "(not set)");
  

• 	for (i = 0; i < be->num_cpu_dai; i++) {
  

• 		struct snd_soc_dai *cpu_dai = be->cpu_dais[i];
  

• 		dev_dbg(card->dev, "ASoC: try BE : %s\n",
  

• 			cpu_dai->playback_widget ?
  

• 			cpu_dai->playback_widget->name : "(not set)");
  
  

• 	if (be->cpu_dai->playback_widget == widget)
  

• 		return be;
  

• 		if (cpu_dai->playback_widget == widget)
  

• 			return be;
  

• 	}
  
  for (i = 0; i < be->num_codecs; i++) {
  	struct snd_soc_dai *dai = be->codec_dais[i];
  

@@ -1326,12 +1464,16 @@ static struct snd_soc_pcm_runtime *dpcm_get_be(struct snd_soc_card *card, 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.

Thanks, Charles