[RFC,v3,2/4] ASoC: Add multiple CPU DAI support for PCM ops

Commit Message

Bard Liao Jan. 16, 2020, 8:26 p.m. UTC

From: Shreyas NC <[e-mail]>

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 <[e-mail]>
Signed-off-by: Shreyas NC <[e-mail]>
Signed-off-by: Kuninori Morimoto <[e-mail]>
Signed-off-by: Bard Liao <[e-mail]>
---
 sound/soc/soc-pcm.c | 521 +++++++++++++++++++++++++++++---------------
 1 file changed, 348 insertions(+), 173 deletions(-)

Comments

Pierre-Louis Bossart Jan. 17, 2020, 11:10 a.m. UTC | #1

I noticed a couple of code changes, we should probably do a code 
refactor first and add those changes, then add the multi-cpu support.

> @@ -892,10 +979,17 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
>   component_err:
>   	soc_pcm_components_hw_free(substream, component);
>   
> -	snd_soc_dai_hw_free(cpu_dai, substream);
> -	cpu_dai->rate = 0;
> +	i = rtd->num_cpus;
>   
>   interface_err:
> +	for_each_rtd_cpu_dai_rollback(rtd, i, cpu_dai) {
> +		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
> +			continue;

maybe this check should be added to the existing code before adding 
multi-cpu support? it looks copy/pasted from the codec case, but is it a 
miss in the existing code?

> +
> +		snd_soc_dai_hw_free(cpu_dai, substream);
> +		cpu_dai->rate = 0;
> +	}
> +

[...]

> @@ -965,7 +1062,12 @@ static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
>   		snd_soc_dai_hw_free(codec_dai, substream);
>   	}
>   
> -	snd_soc_dai_hw_free(cpu_dai, substream);
> +	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
> +		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
> +			continue;
> +
> +		snd_soc_dai_hw_free(cpu_dai, substream);
> +	}

same here, the hw_free should be first made conditional on the stream 
being valid, before introducing multi-cpu-dai support?


> @@ -1672,18 +1804,32 @@ static void dpcm_runtime_merge_chan(struct snd_pcm_substream *substream,
>   
>   	for_each_dpcm_be(fe, stream, dpcm) {
>   		struct snd_soc_pcm_runtime *be = dpcm->be;
> -		struct snd_soc_dai_driver *cpu_dai_drv =  be->cpu_dai->driver;
> +		struct snd_soc_dai_driver *cpu_dai_drv;
>   		struct snd_soc_dai_driver *codec_dai_drv;
>   		struct snd_soc_pcm_stream *codec_stream;
>   		struct snd_soc_pcm_stream *cpu_stream;
> +		struct snd_soc_dai *dai;
> +		int i;
>   
> -		if (stream == SNDRV_PCM_STREAM_PLAYBACK)
> -			cpu_stream = &cpu_dai_drv->playback;
> -		else
> -			cpu_stream = &cpu_dai_drv->capture;
> +		for_each_rtd_cpu_dai(be, i, dai) {
> +			/*
> +			 * Skip CPUs which don't support the current stream
> +			 * type. See soc_pcm_init_runtime_hw() for more details
> +			 */
> +			if (!snd_soc_dai_stream_valid(dai, stream))
> +				continue;

and here as well, this is a new test that didn't exist before?


> @@ -2847,23 +3012,33 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
>   		playback = rtd->dai_link->dpcm_playback;
>   		capture = rtd->dai_link->dpcm_capture;
>   	} else {
> +		int stream_playback;
> +		int stream_capture;
>   		/* Adapt stream for codec2codec links */
> -		struct snd_soc_pcm_stream *cpu_capture = rtd->dai_link->params ?
> -			&cpu_dai->driver->playback : &cpu_dai->driver->capture;
> -		struct snd_soc_pcm_stream *cpu_playback = rtd->dai_link->params ?
> -			&cpu_dai->driver->capture : &cpu_dai->driver->playback;
> +		if (rtd->dai_link->params) {
> +			stream_playback = SNDRV_PCM_STREAM_CAPTURE;
> +			stream_capture  = SNDRV_PCM_STREAM_PLAYBACK;
> +		} else {
> +			stream_playback = SNDRV_PCM_STREAM_PLAYBACK;
> +			stream_capture  = SNDRV_PCM_STREAM_CAPTURE;
> +		}
>   
> -		for_each_rtd_codec_dai(rtd, i, codec_dai) {
> -			if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
> -			    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_PLAYBACK))

the logic for this entire block isn't easy to follow, maybe we should 
first move the cpu case out of the codec_dai loop and refactor the code 
before adding the multi-cpu case.

> -				playback = 1;
> -			if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
> -			    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_CAPTURE))
> -				capture = 1;
> +		playback = 1;
> +		capture = 1;
> +
> +		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
> +			if (!snd_soc_dai_stream_valid(cpu_dai, stream_playback))
> +				playback = 0;
> +			if (!snd_soc_dai_stream_valid(cpu_dai, stream_capture))
> +				capture = 0;
>   		}
>   
> -		capture = capture && cpu_capture->channels_min;
> -		playback = playback && cpu_playback->channels_min;

channels_min is no longer used so it's somewhat confusing if the new 
code is iso-functionality?
I'd prefer a code refactor that we can double check, then add the 
cpu_dai loop.

> +		for_each_rtd_codec_dai(rtd, i, codec_dai) {
> +			if (!snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK))
> +				playback = 0;
> +			if (!snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE))
> +				capture = 0;
> +		}
>   	}
>   
>   	if (rtd->dai_link->playback_only) {
> @@ -2977,7 +3152,7 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
>   out:
>   	dev_info(rtd->card->dev, "%s <-> %s mapping ok\n",
>   		 (rtd->num_codecs > 1) ? "multicodec" : rtd->codec_dai->name,
> -		 cpu_dai->name);
> +		 (rtd->num_cpus > 1) ? "multicpu" : rtd->cpu_dai->name);
>   	return ret;
>   }
>   
>

Liao, Bard Jan. 20, 2020, 11:01 a.m. UTC | #2

> -----Original Message-----
> From: Pierre-Louis Bossart [mailto:[e-mail]]
> Sent: Friday, January 17, 2020 7:11 PM
> To: Bard liao <[e-mail]>; [e-mail];
> [e-mail]
> Cc: [e-mail]; [e-mail];
> [e-mail]; Liao, Bard <[e-mail]>
> Subject: Re: [alsa-devel] [PATCH RFC v3 2/4] ASoC: Add multiple CPU DAI
> support for PCM ops
> 
> I noticed a couple of code changes, we should probably do a code refactor first
> and add those changes, then add the multi-cpu support.
> 
> > @@ -892,10 +979,17 @@ static int soc_pcm_hw_params(struct
> snd_pcm_substream *substream,
> >   component_err:
> >   	soc_pcm_components_hw_free(substream, component);
> >
> > -	snd_soc_dai_hw_free(cpu_dai, substream);
> > -	cpu_dai->rate = 0;
> > +	i = rtd->num_cpus;
> >
> >   interface_err:
> > +	for_each_rtd_cpu_dai_rollback(rtd, i, cpu_dai) {
> > +		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
> > +			continue;
> 
> maybe this check should be added to the existing code before adding multi-cpu
> support? it looks copy/pasted from the codec case, but is it a miss in the existing
> code?

Thanks Pierre for the review. My point is that we don't test
snd_soc_dai_stream_valid in the existing code since we assume the cpu dai
will support the set of all codec dais. For example, the cpu dai will
support both playback and capture  if a dai link with one cpu and two codecs
dai which support playback and capture separated. However, we may have
two cpus dai which support different directions in multi cpu dai link case.

I do see I miss a snd_soc_dai_stream_valid() test above.

> 
> > +
> > +		snd_soc_dai_hw_free(cpu_dai, substream);
> > +		cpu_dai->rate = 0;
> > +	}
> > +
> 
> [...]
> 
> > @@ -965,7 +1062,12 @@ static int soc_pcm_hw_free(struct
> snd_pcm_substream *substream)
> >   		snd_soc_dai_hw_free(codec_dai, substream);
> >   	}
> >
> > -	snd_soc_dai_hw_free(cpu_dai, substream);
> > +	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
> > +		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
> > +			continue;
> > +
> > +		snd_soc_dai_hw_free(cpu_dai, substream);
> > +	}
> 
> same here, the hw_free should be first made conditional on the stream being
> valid, before introducing multi-cpu-dai support?

Or adding multi-cpu-dai support first then checking stream?
The reason is we don't need to test snd_soc_dai_stream_valid if we don't
support multi-cpu-dai

> 
> 
> > @@ -1672,18 +1804,32 @@ static void dpcm_runtime_merge_chan(struct
> snd_pcm_substream *substream,
> >
> >   	for_each_dpcm_be(fe, stream, dpcm) {
> >   		struct snd_soc_pcm_runtime *be = dpcm->be;
> > -		struct snd_soc_dai_driver *cpu_dai_drv =  be->cpu_dai->driver;
> > +		struct snd_soc_dai_driver *cpu_dai_drv;
> >   		struct snd_soc_dai_driver *codec_dai_drv;
> >   		struct snd_soc_pcm_stream *codec_stream;
> >   		struct snd_soc_pcm_stream *cpu_stream;
> > +		struct snd_soc_dai *dai;
> > +		int i;
> >
> > -		if (stream == SNDRV_PCM_STREAM_PLAYBACK)
> > -			cpu_stream = &cpu_dai_drv->playback;
> > -		else
> > -			cpu_stream = &cpu_dai_drv->capture;
> > +		for_each_rtd_cpu_dai(be, i, dai) {
> > +			/*
> > +			 * Skip CPUs which don't support the current stream
> > +			 * type. See soc_pcm_init_runtime_hw() for more
> details
> > +			 */
> > +			if (!snd_soc_dai_stream_valid(dai, stream))
> > +				continue;
> 
> and here as well, this is a new test that didn't exist before?
> 
> 
> > @@ -2847,23 +3012,33 @@ int soc_new_pcm(struct snd_soc_pcm_runtime
> *rtd, int num)
> >   		playback = rtd->dai_link->dpcm_playback;
> >   		capture = rtd->dai_link->dpcm_capture;
> >   	} else {
> > +		int stream_playback;
> > +		int stream_capture;
> >   		/* Adapt stream for codec2codec links */
> > -		struct snd_soc_pcm_stream *cpu_capture = rtd->dai_link-
> >params ?
> > -			&cpu_dai->driver->playback : &cpu_dai->driver-
> >capture;
> > -		struct snd_soc_pcm_stream *cpu_playback = rtd->dai_link-
> >params ?
> > -			&cpu_dai->driver->capture : &cpu_dai->driver-
> >playback;
> > +		if (rtd->dai_link->params) {
> > +			stream_playback = SNDRV_PCM_STREAM_CAPTURE;
> > +			stream_capture  = SNDRV_PCM_STREAM_PLAYBACK;
> > +		} else {
> > +			stream_playback = SNDRV_PCM_STREAM_PLAYBACK;
> > +			stream_capture  = SNDRV_PCM_STREAM_CAPTURE;
> > +		}
> >
> > -		for_each_rtd_codec_dai(rtd, i, codec_dai) {
> > -			if (snd_soc_dai_stream_valid(codec_dai,
> SNDRV_PCM_STREAM_PLAYBACK) &&
> > -			    snd_soc_dai_stream_valid(cpu_dai,
> SNDRV_PCM_STREAM_PLAYBACK))
> 
> the logic for this entire block isn't easy to follow, maybe we should
> first move the cpu case out of the codec_dai loop and refactor the code
> before adding the multi-cpu case.

I will try to split the patch.

> 
> > -				playback = 1;
> > -			if (snd_soc_dai_stream_valid(codec_dai,
> SNDRV_PCM_STREAM_CAPTURE) &&
> > -			    snd_soc_dai_stream_valid(cpu_dai,
> SNDRV_PCM_STREAM_CAPTURE))
> > -				capture = 1;
> > +		playback = 1;
> > +		capture = 1;
> > +
> > +		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
> > +			if (!snd_soc_dai_stream_valid(cpu_dai,
> stream_playback))
> > +				playback = 0;
> > +			if (!snd_soc_dai_stream_valid(cpu_dai,
> stream_capture))
> > +				capture = 0;
> >   		}
> >
> > -		capture = capture && cpu_capture->channels_min;
> > -		playback = playback && cpu_playback->channels_min;
> 
> channels_min is no longer used so it's somewhat confusing if the new
> code is iso-functionality?

channels_min is to check if the stream is valid. It is  replaced by
snd_soc_dai_stream_valid().

> I'd prefer a code refactor that we can double check, then add the
> cpu_dai loop.
> 
> > +		for_each_rtd_codec_dai(rtd, i, codec_dai) {
> > +			if (!snd_soc_dai_stream_valid(codec_dai,
> SNDRV_PCM_STREAM_PLAYBACK))
> > +				playback = 0;
> > +			if (!snd_soc_dai_stream_valid(codec_dai,
> SNDRV_PCM_STREAM_CAPTURE))
> > +				capture = 0;
> > +		}
> >   	}
> >
> >   	if (rtd->dai_link->playback_only) {
> > @@ -2977,7 +3152,7 @@ int soc_new_pcm(struct snd_soc_pcm_runtime *rtd,
> int num)
> >   out:
> >   	dev_info(rtd->card->dev, "%s <-> %s mapping ok\n",
> >   		 (rtd->num_codecs > 1) ? "multicodec" : rtd->codec_dai->name,
> > -		 cpu_dai->name);
> > +		 (rtd->num_cpus > 1) ? "multicpu" : rtd->cpu_dai->name);
> >   	return ret;
> >   }
> >
> >

Patch

diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index 74d340d1c9f7..ae1017637e86 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -40,24 +40,28 @@ 
  */
 void snd_soc_runtime_activate(struct snd_soc_pcm_runtime *rtd, int stream)
 {
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i;
 
 	lockdep_assert_held(&rtd->card->pcm_mutex);
 
 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
-		cpu_dai->playback_active++;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+			cpu_dai->playback_active++;
 		for_each_rtd_codec_dai(rtd, i, codec_dai)
 			codec_dai->playback_active++;
 	} else {
-		cpu_dai->capture_active++;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+			cpu_dai->capture_active++;
 		for_each_rtd_codec_dai(rtd, i, codec_dai)
 			codec_dai->capture_active++;
 	}
 
-	cpu_dai->active++;
-	cpu_dai->component->active++;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		cpu_dai->active++;
+		cpu_dai->component->active++;
+	}
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 		codec_dai->active++;
 		codec_dai->component->active++;
@@ -76,24 +80,28 @@  void snd_soc_runtime_activate(struct snd_soc_pcm_runtime *rtd, int stream)
  */
 void snd_soc_runtime_deactivate(struct snd_soc_pcm_runtime *rtd, int stream)
 {
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i;
 
 	lockdep_assert_held(&rtd->card->pcm_mutex);
 
 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
-		cpu_dai->playback_active--;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+			cpu_dai->playback_active--;
 		for_each_rtd_codec_dai(rtd, i, codec_dai)
 			codec_dai->playback_active--;
 	} else {
-		cpu_dai->capture_active--;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+			cpu_dai->capture_active--;
 		for_each_rtd_codec_dai(rtd, i, codec_dai)
 			codec_dai->capture_active--;
 	}
 
-	cpu_dai->active--;
-	cpu_dai->component->active--;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		cpu_dai->active--;
+		cpu_dai->component->active--;
+	}
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 		codec_dai->component->active--;
 		codec_dai->active--;
@@ -233,7 +241,7 @@  static int soc_pcm_params_symmetry(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	unsigned int rate, channels, sample_bits, symmetry, i;
 
@@ -242,40 +250,60 @@  static int soc_pcm_params_symmetry(struct snd_pcm_substream *substream,
 	sample_bits = snd_pcm_format_physical_width(params_format(params));
 
 	/* reject unmatched parameters when applying symmetry */
-	symmetry = cpu_dai->driver->symmetric_rates ||
-		rtd->dai_link->symmetric_rates;
+	symmetry = rtd->dai_link->symmetric_rates;
+
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		symmetry |= cpu_dai->driver->symmetric_rates;
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai)
 		symmetry |= codec_dai->driver->symmetric_rates;
 
-	if (symmetry && cpu_dai->rate && cpu_dai->rate != rate) {
-		dev_err(rtd->dev, "ASoC: unmatched rate symmetry: %d - %d\n",
-				cpu_dai->rate, rate);
-		return -EINVAL;
+	if (symmetry) {
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (cpu_dai->rate && cpu_dai->rate != rate) {
+				dev_err(rtd->dev, "ASoC: unmatched rate symmetry: %d - %d\n",
+					cpu_dai->rate, rate);
+				return -EINVAL;
+			}
+		}
 	}
 
-	symmetry = cpu_dai->driver->symmetric_channels ||
-		rtd->dai_link->symmetric_channels;
+	symmetry = rtd->dai_link->symmetric_channels;
+
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		symmetry |= cpu_dai->driver->symmetric_channels;
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai)
 		symmetry |= codec_dai->driver->symmetric_channels;
 
-	if (symmetry && cpu_dai->channels && cpu_dai->channels != channels) {
-		dev_err(rtd->dev, "ASoC: unmatched channel symmetry: %d - %d\n",
-				cpu_dai->channels, channels);
-		return -EINVAL;
+	if (symmetry) {
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (cpu_dai->channels &&
+			    cpu_dai->channels != channels) {
+				dev_err(rtd->dev, "ASoC: unmatched channel symmetry: %d - %d\n",
+					cpu_dai->channels, channels);
+				return -EINVAL;
+			}
+		}
 	}
 
-	symmetry = cpu_dai->driver->symmetric_samplebits ||
-		rtd->dai_link->symmetric_samplebits;
+	symmetry = rtd->dai_link->symmetric_samplebits;
+
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		symmetry |= cpu_dai->driver->symmetric_samplebits;
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai)
 		symmetry |= codec_dai->driver->symmetric_samplebits;
 
-	if (symmetry && cpu_dai->sample_bits && cpu_dai->sample_bits != sample_bits) {
-		dev_err(rtd->dev, "ASoC: unmatched sample bits symmetry: %d - %d\n",
-				cpu_dai->sample_bits, sample_bits);
-		return -EINVAL;
+	if (symmetry) {
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (cpu_dai->sample_bits &&
+			    cpu_dai->sample_bits != sample_bits) {
+				dev_err(rtd->dev, "ASoC: unmatched sample bits symmetry: %d - %d\n",
+					cpu_dai->sample_bits, sample_bits);
+				return -EINVAL;
+			}
+		}
 	}
 
 	return 0;
@@ -284,14 +312,20 @@  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;
 	struct snd_soc_dai *codec_dai;
+	struct snd_soc_dai *cpu_dai;
 	unsigned int symmetry, i;
 
-	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;
+
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		symmetry = symmetry ||
+			cpu_dai->driver->symmetric_rates ||
+			cpu_dai->driver->symmetric_channels ||
+			cpu_dai->driver->symmetric_samplebits;
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai)
 		symmetry = symmetry ||
@@ -319,10 +353,10 @@  static void soc_pcm_set_msb(struct snd_pcm_substream *substream, int bits)
 static void soc_pcm_apply_msb(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i;
-	unsigned int bits = 0, cpu_bits;
+	unsigned int bits = 0, cpu_bits = 0;
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		for_each_rtd_codec_dai(rtd, i, codec_dai) {
@@ -332,7 +366,14 @@  static void soc_pcm_apply_msb(struct snd_pcm_substream *substream)
 			}
 			bits = max(codec_dai->driver->playback.sig_bits, bits);
 		}
-		cpu_bits = cpu_dai->driver->playback.sig_bits;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (cpu_dai->driver->playback.sig_bits == 0) {
+				cpu_bits = 0;
+				break;
+			}
+			cpu_bits = max(cpu_dai->driver->playback.sig_bits,
+				       bits);
+		}
 	} else {
 		for_each_rtd_codec_dai(rtd, i, codec_dai) {
 			if (codec_dai->driver->capture.sig_bits == 0) {
@@ -341,7 +382,13 @@  static void soc_pcm_apply_msb(struct snd_pcm_substream *substream)
 			}
 			bits = max(codec_dai->driver->capture.sig_bits, bits);
 		}
-		cpu_bits = cpu_dai->driver->capture.sig_bits;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (cpu_dai->driver->capture.sig_bits == 0) {
+				cpu_bits = 0;
+				break;
+			}
+			cpu_bits = max(cpu_dai->driver->capture.sig_bits, bits);
+		}
 	}
 
 	soc_pcm_set_msb(substream, bits);
@@ -354,22 +401,40 @@  static void soc_pcm_init_runtime_hw(struct snd_pcm_substream *substream)
 	struct snd_pcm_hardware *hw = &runtime->hw;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_dai *codec_dai;
-	struct snd_soc_dai_driver *cpu_dai_drv = rtd->cpu_dai->driver;
+	struct snd_soc_dai *cpu_dai;
+	struct snd_soc_dai_driver *cpu_dai_drv;
 	struct snd_soc_dai_driver *codec_dai_drv;
 	struct snd_soc_pcm_stream *codec_stream;
 	struct snd_soc_pcm_stream *cpu_stream;
 	unsigned int chan_min = 0, chan_max = UINT_MAX;
+	unsigned int cpu_chan_min = 0, cpu_chan_max = UINT_MAX;
 	unsigned int rate_min = 0, rate_max = UINT_MAX;
-	unsigned int rates = UINT_MAX;
+	unsigned int cpu_rate_min = 0, cpu_rate_max = UINT_MAX;
+	unsigned int rates = UINT_MAX, cpu_rates = UINT_MAX;
 	u64 formats = ULLONG_MAX;
 	int i;
 
-	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-		cpu_stream = &cpu_dai_drv->playback;
-	else
-		cpu_stream = &cpu_dai_drv->capture;
+	/* first calculate min/max only for CPUs in the DAI link */
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		if (!snd_soc_dai_stream_valid(cpu_dai,
+					      substream->stream))
+			continue;
+
+		cpu_dai_drv = cpu_dai->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(cpu_chan_min, cpu_stream->channels_min);
+		cpu_chan_max = min(cpu_chan_max, cpu_stream->channels_max);
+		cpu_rate_min = max(cpu_rate_min, cpu_stream->rate_min);
+		cpu_rate_max = min_not_zero(cpu_rate_max, cpu_stream->rate_max);
+		formats &= cpu_stream->formats;
+		cpu_rates = snd_pcm_rate_mask_intersect(cpu_stream->rates,
+							cpu_rates);
+	}
 
-	/* first calculate min/max only for CODECs in the DAI link */
+	/* second calculate min/max only for CODECs in the DAI link */
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 
 		/*
@@ -400,27 +465,28 @@  static void soc_pcm_init_runtime_hw(struct snd_pcm_substream *substream)
 
 	/*
 	 * chan min/max cannot be enforced if there are multiple CODEC DAIs
-	 * connected to a single CPU DAI, use CPU DAI's directly and let
+	 * connected to CPU DAI(s), use CPU DAI's directly and let
 	 * channel allocation be fixed up later
 	 */
 	if (rtd->num_codecs > 1) {
-		chan_min = cpu_stream->channels_min;
-		chan_max = cpu_stream->channels_max;
+		chan_min = cpu_chan_min;
+		chan_max = cpu_chan_max;
 	}
 
-	hw->channels_min = max(chan_min, cpu_stream->channels_min);
-	hw->channels_max = min(chan_max, cpu_stream->channels_max);
+	/* finally find a intersection between CODECs and CPUs */
+	hw->channels_min = max(chan_min, cpu_chan_min);
+	hw->channels_max = min(chan_max, cpu_chan_max);
 	if (hw->formats)
-		hw->formats &= formats & cpu_stream->formats;
+		hw->formats &= formats;
 	else
-		hw->formats = formats & cpu_stream->formats;
-	hw->rates = snd_pcm_rate_mask_intersect(rates, cpu_stream->rates);
+		hw->formats = formats;
+	hw->rates = snd_pcm_rate_mask_intersect(rates, cpu_rates);
 
 	snd_pcm_limit_hw_rates(runtime);
 
-	hw->rate_min = max(hw->rate_min, cpu_stream->rate_min);
+	hw->rate_min = max(hw->rate_min, cpu_rate_min);
 	hw->rate_min = max(hw->rate_min, rate_min);
-	hw->rate_max = min_not_zero(hw->rate_max, cpu_stream->rate_max);
+	hw->rate_max = min_not_zero(hw->rate_max, cpu_rate_max);
 	hw->rate_max = min_not_zero(hw->rate_max, rate_max);
 }
 
@@ -482,9 +548,10 @@  static int soc_pcm_open(struct snd_pcm_substream *substream)
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_component *component;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	const char *codec_dai_name = "multicodec";
+	const char *cpu_dai_name = "multicpu";
 	int i, ret = 0;
 
 	for_each_rtd_components(rtd, i, component)
@@ -496,11 +563,13 @@  static int soc_pcm_open(struct snd_pcm_substream *substream)
 	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	/* startup the audio subsystem */
-	ret = snd_soc_dai_startup(cpu_dai, substream);
-	if (ret < 0) {
-		dev_err(cpu_dai->dev, "ASoC: can't open interface %s: %d\n",
-			cpu_dai->name, ret);
-		goto out;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		ret = snd_soc_dai_startup(cpu_dai, substream);
+		if (ret < 0) {
+			dev_err(cpu_dai->dev, "ASoC: can't open interface %s: %d\n",
+				cpu_dai->name, ret);
+			goto interface_err;
+		}
 	}
 
 	ret = soc_pcm_components_open(substream, &component);
@@ -541,34 +610,39 @@  static int soc_pcm_open(struct snd_pcm_substream *substream)
 	if (rtd->num_codecs == 1)
 		codec_dai_name = rtd->codec_dai->name;
 
+	if (rtd->num_cpus == 1)
+		cpu_dai_name = rtd->cpu_dai->name;
+
 	if (soc_pcm_has_symmetry(substream))
 		runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;
 
 	ret = -EINVAL;
 	if (!runtime->hw.rates) {
 		printk(KERN_ERR "ASoC: %s <-> %s No matching rates\n",
-			codec_dai_name, cpu_dai->name);
+			codec_dai_name, cpu_dai_name);
 		goto config_err;
 	}
 	if (!runtime->hw.formats) {
 		printk(KERN_ERR "ASoC: %s <-> %s No matching formats\n",
-			codec_dai_name, cpu_dai->name);
+			codec_dai_name, cpu_dai_name);
 		goto config_err;
 	}
 	if (!runtime->hw.channels_min || !runtime->hw.channels_max ||
 	    runtime->hw.channels_min > runtime->hw.channels_max) {
 		printk(KERN_ERR "ASoC: %s <-> %s No matching channels\n",
-				codec_dai_name, cpu_dai->name);
+				codec_dai_name, cpu_dai_name);
 		goto config_err;
 	}
 
 	soc_pcm_apply_msb(substream);
 
 	/* Symmetry only applies if we've already got an active stream. */
-	if (cpu_dai->active) {
-		ret = soc_pcm_apply_symmetry(substream, cpu_dai);
-		if (ret != 0)
-			goto config_err;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		if (cpu_dai->active) {
+			ret = soc_pcm_apply_symmetry(substream, cpu_dai);
+			if (ret != 0)
+				goto config_err;
+		}
 	}
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
@@ -580,7 +654,7 @@  static int soc_pcm_open(struct snd_pcm_substream *substream)
 	}
 
 	pr_debug("ASoC: %s <-> %s info:\n",
-			codec_dai_name, cpu_dai->name);
+		 codec_dai_name, cpu_dai_name);
 	pr_debug("ASoC: rate mask 0x%x\n", runtime->hw.rates);
 	pr_debug("ASoC: min ch %d max ch %d\n", runtime->hw.channels_min,
 		 runtime->hw.channels_max);
@@ -608,8 +682,12 @@  static int soc_pcm_open(struct snd_pcm_substream *substream)
 component_err:
 	soc_pcm_components_close(substream, component);
 
-	snd_soc_dai_shutdown(cpu_dai, substream);
-out:
+	i = rtd->num_cpus;
+
+interface_err:
+	for_each_rtd_cpu_dai_rollback(rtd, i, cpu_dai)
+		snd_soc_dai_shutdown(cpu_dai, substream);
+
 	mutex_unlock(&rtd->card->pcm_mutex);
 
 	for_each_rtd_components(rtd, i, component) {
@@ -643,7 +721,7 @@  static int soc_pcm_close(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_component *component;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i;
 
@@ -652,17 +730,21 @@  static int soc_pcm_close(struct snd_pcm_substream *substream)
 	snd_soc_runtime_deactivate(rtd, substream->stream);
 
 	/* clear the corresponding DAIs rate when inactive */
-	if (!cpu_dai->active)
-		cpu_dai->rate = 0;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		if (!cpu_dai->active)
+			cpu_dai->rate = 0;
+	}
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 		if (!codec_dai->active)
 			codec_dai->rate = 0;
 	}
 
-	snd_soc_dai_digital_mute(cpu_dai, 1, substream->stream);
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		snd_soc_dai_digital_mute(cpu_dai, 1, substream->stream);
 
-	snd_soc_dai_shutdown(cpu_dai, substream);
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		snd_soc_dai_shutdown(cpu_dai, substream);
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai)
 		snd_soc_dai_shutdown(codec_dai, substream);
@@ -697,7 +779,7 @@  static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_component *component;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i, ret = 0;
 
@@ -731,11 +813,13 @@  static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 		}
 	}
 
-	ret = snd_soc_dai_prepare(cpu_dai, substream);
-	if (ret < 0) {
-		dev_err(cpu_dai->dev,
-			"ASoC: cpu DAI prepare error: %d\n", ret);
-		goto out;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		ret = snd_soc_dai_prepare(cpu_dai, substream);
+		if (ret < 0) {
+			dev_err(cpu_dai->dev,
+				"ASoC: cpu DAI prepare error: %d\n", ret);
+			goto out;
+		}
 	}
 
 	/* cancel any delayed stream shutdown that is pending */
@@ -751,7 +835,8 @@  static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 	for_each_rtd_codec_dai(rtd, i, codec_dai)
 		snd_soc_dai_digital_mute(codec_dai, 0,
 					 substream->stream);
-	snd_soc_dai_digital_mute(cpu_dai, 0, substream->stream);
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai)
+		snd_soc_dai_digital_mute(cpu_dai, 0, substream->stream);
 
 out:
 	mutex_unlock(&rtd->card->pcm_mutex);
@@ -796,7 +881,7 @@  static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_component *component;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i, ret = 0;
 
@@ -862,17 +947,19 @@  static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 		snd_soc_dapm_update_dai(substream, &codec_params, codec_dai);
 	}
 
-	ret = snd_soc_dai_hw_params(cpu_dai, substream, params);
-	if (ret < 0)
-		goto interface_err;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		ret = snd_soc_dai_hw_params(cpu_dai, substream, params);
+		if (ret < 0)
+			goto interface_err;
 
-	/* store the parameters for each DAIs */
-	cpu_dai->rate = params_rate(params);
-	cpu_dai->channels = params_channels(params);
-	cpu_dai->sample_bits =
-		snd_pcm_format_physical_width(params_format(params));
+		/* store the parameters for each DAI */
+		cpu_dai->rate = params_rate(params);
+		cpu_dai->channels = params_channels(params);
+		cpu_dai->sample_bits =
+			snd_pcm_format_physical_width(params_format(params));
 
-	snd_soc_dapm_update_dai(substream, params, cpu_dai);
+		snd_soc_dapm_update_dai(substream, params, cpu_dai);
+	}
 
 	for_each_rtd_components(rtd, i, component) {
 		ret = snd_soc_component_hw_params(component, substream, params);
@@ -892,10 +979,17 @@  static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 component_err:
 	soc_pcm_components_hw_free(substream, component);
 
-	snd_soc_dai_hw_free(cpu_dai, substream);
-	cpu_dai->rate = 0;
+	i = rtd->num_cpus;
 
 interface_err:
+	for_each_rtd_cpu_dai_rollback(rtd, i, cpu_dai) {
+		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
+			continue;
+
+		snd_soc_dai_hw_free(cpu_dai, substream);
+		cpu_dai->rate = 0;
+	}
+
 	i = rtd->num_codecs;
 
 codec_err:
@@ -920,20 +1014,23 @@  static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	bool playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	int i;
 
 	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
-	/* clear the corresponding DAIs parameters when going to be inactive */
-	if (cpu_dai->active == 1) {
-		cpu_dai->rate = 0;
-		cpu_dai->channels = 0;
-		cpu_dai->sample_bits = 0;
+	/* clear all CPU DAIs parameters when inactive */
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		if (cpu_dai->active == 1) {
+			cpu_dai->rate = 0;
+			cpu_dai->channels = 0;
+			cpu_dai->sample_bits = 0;
+		}
 	}
 
+	/* clear all CODEC DAIs parameters when inactive */
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 		if (codec_dai->active == 1) {
 			codec_dai->rate = 0;
@@ -965,7 +1062,12 @@  static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 		snd_soc_dai_hw_free(codec_dai, substream);
 	}
 
-	snd_soc_dai_hw_free(cpu_dai, substream);
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		if (!snd_soc_dai_stream_valid(cpu_dai, substream->stream))
+			continue;
+
+		snd_soc_dai_hw_free(cpu_dai, substream);
+	}
 
 	mutex_unlock(&rtd->card->pcm_mutex);
 	return 0;
@@ -975,7 +1077,7 @@  static int soc_pcm_trigger_start(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_component *component;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i, ret;
 
@@ -991,9 +1093,11 @@  static int soc_pcm_trigger_start(struct snd_pcm_substream *substream, int cmd)
 			return ret;
 	}
 
-	ret = snd_soc_dai_trigger(cpu_dai, substream, cmd);
-	if (ret < 0)
-		return ret;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		ret = snd_soc_dai_trigger(cpu_dai, substream, cmd);
+		if (ret < 0)
+			return ret;
+	}
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 		ret = snd_soc_dai_trigger(codec_dai, substream, cmd);
@@ -1008,7 +1112,7 @@  static int soc_pcm_trigger_stop(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_component *component;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i, ret;
 
@@ -1018,9 +1122,11 @@  static int soc_pcm_trigger_stop(struct snd_pcm_substream *substream, int cmd)
 			return ret;
 	}
 
-	ret = snd_soc_dai_trigger(cpu_dai, substream, cmd);
-	if (ret < 0)
-		return ret;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		ret = snd_soc_dai_trigger(cpu_dai, substream, cmd);
+		if (ret < 0)
+			return ret;
+	}
 
 	for_each_rtd_components(rtd, i, component) {
 		ret = snd_soc_component_trigger(component, substream, cmd);
@@ -1063,7 +1169,7 @@  static int soc_pcm_bespoke_trigger(struct snd_pcm_substream *substream,
 				   int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_dai *codec_dai;
 	int i, ret;
 
@@ -1073,9 +1179,11 @@  static int soc_pcm_bespoke_trigger(struct snd_pcm_substream *substream,
 			return ret;
 	}
 
-	ret = snd_soc_dai_bespoke_trigger(cpu_dai, substream, cmd);
-	if (ret < 0)
-		return ret;
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		ret = snd_soc_dai_bespoke_trigger(cpu_dai, substream, cmd);
+		if (ret < 0)
+			return ret;
+	}
 
 	return 0;
 }
@@ -1087,12 +1195,13 @@  static int soc_pcm_bespoke_trigger(struct snd_pcm_substream *substream,
 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_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;
 	snd_pcm_sframes_t delay = 0;
 	snd_pcm_sframes_t codec_delay = 0;
+	snd_pcm_sframes_t cpu_delay = 0;
 	int i;
 
 	/* clearing the previous total delay */
@@ -1103,7 +1212,11 @@  static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
 	/* base delay if assigned in pointer callback */
 	delay = runtime->delay;
 
-	delay += snd_soc_dai_delay(cpu_dai, substream);
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		cpu_delay = max(cpu_delay,
+				snd_soc_dai_delay(cpu_dai, substream));
+	}
+	delay += cpu_delay;
 
 	for_each_rtd_codec_dai(rtd, i, codec_dai) {
 		codec_delay = max(codec_delay,
@@ -1229,6 +1342,7 @@  static struct snd_soc_pcm_runtime *dpcm_get_be(struct snd_soc_card *card,
 {
 	struct snd_soc_pcm_runtime *be;
 	struct snd_soc_dai *dai;
+	struct snd_soc_dai *cpu_dai;
 	int i;
 
 	dev_dbg(card->dev, "ASoC: find BE for widget %s\n", widget->name);
@@ -1239,12 +1353,15 @@  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_each_rtd_cpu_dai(be, i, cpu_dai) {
+				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_each_rtd_codec_dai(be, i, dai) {
 				if (dai->playback_widget == widget)
@@ -1258,12 +1375,15 @@  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_each_rtd_cpu_dai(be, i, cpu_dai) {
+				dev_dbg(card->dev, "ASoC: try BE %s\n",
+					cpu_dai->capture_widget ?
+					cpu_dai->capture_widget->name :
+					"(not set)");
 
-			if (be->cpu_dai->capture_widget == widget)
-				return be;
+				if (cpu_dai->capture_widget == widget)
+					return be;
+			}
 
 			for_each_rtd_codec_dai(be, i, dai) {
 				if (dai->capture_widget == widget)
@@ -1313,8 +1433,10 @@  static bool dpcm_end_walk_at_be(struct snd_soc_dapm_widget *widget,
 			if (!rtd->dai_link->no_pcm)
 				continue;
 
-			if (rtd->cpu_dai->playback_widget == widget)
-				return true;
+			for_each_rtd_cpu_dai(rtd, i, dai) {
+				if (dai->playback_widget == widget)
+					return true;
+			}
 
 			for_each_rtd_codec_dai(rtd, i, dai) {
 				if (dai->playback_widget == widget)
@@ -1326,8 +1448,10 @@  static bool dpcm_end_walk_at_be(struct snd_soc_dapm_widget *widget,
 			if (!rtd->dai_link->no_pcm)
 				continue;
 
-			if (rtd->cpu_dai->capture_widget == widget)
-				return true;
+			for_each_rtd_cpu_dai(rtd, i, dai) {
+				if (dai->capture_widget == widget)
+					return true;
+			}
 
 			for_each_rtd_codec_dai(rtd, i, dai) {
 				if (dai->capture_widget == widget)
@@ -1370,10 +1494,18 @@  static int dpcm_prune_paths(struct snd_soc_pcm_runtime *fe, int stream,
 		unsigned int i;
 
 		/* is there a valid CPU DAI widget for this BE */
-		widget = dai_get_widget(dpcm->be->cpu_dai, stream);
+		do_prune = 1;
+		for_each_rtd_cpu_dai(dpcm->be, i, dai) {
+			widget = dai_get_widget(dai, stream);
 
-		/* prune the BE if it's no longer in our active list */
-		if (widget && widget_in_list(list, widget))
+			/*
+			 * The BE is pruned only if none of the cpu_dai
+			 * widgets are in the active list.
+			 */
+			if (widget && widget_in_list(list, widget))
+				do_prune = 0;
+		}
+		if (!do_prune)
 			continue;
 
 		/* is there a valid CODEC DAI widget for this BE */
@@ -1672,18 +1804,32 @@  static void dpcm_runtime_merge_chan(struct snd_pcm_substream *substream,
 
 	for_each_dpcm_be(fe, stream, dpcm) {
 		struct snd_soc_pcm_runtime *be = dpcm->be;
-		struct snd_soc_dai_driver *cpu_dai_drv =  be->cpu_dai->driver;
+		struct snd_soc_dai_driver *cpu_dai_drv;
 		struct snd_soc_dai_driver *codec_dai_drv;
 		struct snd_soc_pcm_stream *codec_stream;
 		struct snd_soc_pcm_stream *cpu_stream;
+		struct snd_soc_dai *dai;
+		int i;
 
-		if (stream == SNDRV_PCM_STREAM_PLAYBACK)
-			cpu_stream = &cpu_dai_drv->playback;
-		else
-			cpu_stream = &cpu_dai_drv->capture;
+		for_each_rtd_cpu_dai(be, i, dai) {
+			/*
+			 * Skip CPUs which don't support the current stream
+			 * type. See soc_pcm_init_runtime_hw() for more details
+			 */
+			if (!snd_soc_dai_stream_valid(dai, stream))
+				continue;
 
-		*channels_min = max(*channels_min, cpu_stream->channels_min);
-		*channels_max = min(*channels_max, cpu_stream->channels_max);
+			cpu_dai_drv =  dai->driver;
+			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+				cpu_stream = &cpu_dai_drv->playback;
+			else
+				cpu_stream = &cpu_dai_drv->capture;
+
+			*channels_min = max(*channels_min,
+					    cpu_stream->channels_min);
+			*channels_max = min(*channels_max,
+					    cpu_stream->channels_max);
+		}
 
 		/*
 		 * chan min/max cannot be enforced if there are multiple CODEC
@@ -1724,21 +1870,33 @@  static void dpcm_runtime_merge_rate(struct snd_pcm_substream *substream,
 
 	for_each_dpcm_be(fe, stream, dpcm) {
 		struct snd_soc_pcm_runtime *be = dpcm->be;
-		struct snd_soc_dai_driver *cpu_dai_drv =  be->cpu_dai->driver;
+		struct snd_soc_dai_driver *cpu_dai_drv;
 		struct snd_soc_dai_driver *codec_dai_drv;
 		struct snd_soc_pcm_stream *codec_stream;
 		struct snd_soc_pcm_stream *cpu_stream;
 		struct snd_soc_dai *dai;
 		int i;
 
-		if (stream == SNDRV_PCM_STREAM_PLAYBACK)
-			cpu_stream = &cpu_dai_drv->playback;
-		else
-			cpu_stream = &cpu_dai_drv->capture;
+		for_each_rtd_cpu_dai(be, i, dai) {
+			/*
+			 * Skip CPUs which don't support the current stream
+			 * type. See soc_pcm_init_runtime_hw() for more details
+			 */
+			if (!snd_soc_dai_stream_valid(dai, stream))
+				continue;
 
-		*rate_min = max(*rate_min, cpu_stream->rate_min);
-		*rate_max = min_not_zero(*rate_max, cpu_stream->rate_max);
-		*rates = snd_pcm_rate_mask_intersect(*rates, cpu_stream->rates);
+			cpu_dai_drv =  dai->driver;
+			if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+				cpu_stream = &cpu_dai_drv->playback;
+			else
+				cpu_stream = &cpu_dai_drv->capture;
+
+			*rate_min = max(*rate_min, cpu_stream->rate_min);
+			*rate_max = min_not_zero(*rate_max,
+						 cpu_stream->rate_max);
+			*rates = snd_pcm_rate_mask_intersect(*rates,
+						cpu_stream->rates);
+		}
 
 		for_each_rtd_codec_dai(be, i, dai) {
 			/*
@@ -1767,13 +1925,17 @@  static void dpcm_set_fe_runtime(struct snd_pcm_substream *substream)
 {
 	struct snd_pcm_runtime *runtime = substream->runtime;
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
-	struct snd_soc_dai_driver *cpu_dai_drv = cpu_dai->driver;
+	struct snd_soc_dai *cpu_dai;
+	struct snd_soc_dai_driver *cpu_dai_drv;
+	int i;
 
-	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
-		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback);
-	else
-		dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture);
+	for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+		cpu_dai_drv = cpu_dai->driver;
+		if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+			dpcm_init_runtime_hw(runtime, &cpu_dai_drv->playback);
+		else
+			dpcm_init_runtime_hw(runtime, &cpu_dai_drv->capture);
+	}
 
 	dpcm_runtime_merge_format(substream, &runtime->hw.formats);
 	dpcm_runtime_merge_chan(substream, &runtime->hw.channels_min,
@@ -1831,6 +1993,7 @@  static int dpcm_apply_symmetry(struct snd_pcm_substream *fe_substream,
 			snd_soc_dpcm_get_substream(be, stream);
 		struct snd_soc_pcm_runtime *rtd;
 		struct snd_soc_dai *codec_dai;
+		struct snd_soc_dai *cpu_dai;
 		int i;
 
 		/* A backend may not have the requested substream */
@@ -1845,11 +2008,13 @@  static int dpcm_apply_symmetry(struct snd_pcm_substream *fe_substream,
 			be_substream->runtime->hw.info |= SNDRV_PCM_INFO_JOINT_DUPLEX;
 
 		/* Symmetry only applies if we've got an active stream. */
-		if (rtd->cpu_dai->active) {
-			err = soc_pcm_apply_symmetry(fe_substream,
-						     rtd->cpu_dai);
-			if (err < 0)
-				return err;
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (cpu_dai->active) {
+				err = soc_pcm_apply_symmetry(fe_substream,
+							     cpu_dai);
+				if (err < 0)
+					return err;
+			}
 		}
 
 		for_each_rtd_codec_dai(rtd, i, codec_dai) {
@@ -2836,7 +3001,7 @@  static int dpcm_fe_dai_close(struct snd_pcm_substream *fe_substream)
 int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 {
 	struct snd_soc_dai *codec_dai;
-	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
+	struct snd_soc_dai *cpu_dai;
 	struct snd_soc_component *component;
 	struct snd_pcm *pcm;
 	char new_name[64];
@@ -2847,23 +3012,33 @@  int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 		playback = rtd->dai_link->dpcm_playback;
 		capture = rtd->dai_link->dpcm_capture;
 	} else {
+		int stream_playback;
+		int stream_capture;
 		/* Adapt stream for codec2codec links */
-		struct snd_soc_pcm_stream *cpu_capture = rtd->dai_link->params ?
-			&cpu_dai->driver->playback : &cpu_dai->driver->capture;
-		struct snd_soc_pcm_stream *cpu_playback = rtd->dai_link->params ?
-			&cpu_dai->driver->capture : &cpu_dai->driver->playback;
+		if (rtd->dai_link->params) {
+			stream_playback = SNDRV_PCM_STREAM_CAPTURE;
+			stream_capture  = SNDRV_PCM_STREAM_PLAYBACK;
+		} else {
+			stream_playback = SNDRV_PCM_STREAM_PLAYBACK;
+			stream_capture  = SNDRV_PCM_STREAM_CAPTURE;
+		}
 
-		for_each_rtd_codec_dai(rtd, i, codec_dai) {
-			if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK) &&
-			    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_PLAYBACK))
-				playback = 1;
-			if (snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE) &&
-			    snd_soc_dai_stream_valid(cpu_dai,   SNDRV_PCM_STREAM_CAPTURE))
-				capture = 1;
+		playback = 1;
+		capture = 1;
+
+		for_each_rtd_cpu_dai(rtd, i, cpu_dai) {
+			if (!snd_soc_dai_stream_valid(cpu_dai, stream_playback))
+				playback = 0;
+			if (!snd_soc_dai_stream_valid(cpu_dai, stream_capture))
+				capture = 0;
 		}
 
-		capture = capture && cpu_capture->channels_min;
-		playback = playback && cpu_playback->channels_min;
+		for_each_rtd_codec_dai(rtd, i, codec_dai) {
+			if (!snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_PLAYBACK))
+				playback = 0;
+			if (!snd_soc_dai_stream_valid(codec_dai, SNDRV_PCM_STREAM_CAPTURE))
+				capture = 0;
+		}
 	}
 
 	if (rtd->dai_link->playback_only) {
@@ -2977,7 +3152,7 @@  int soc_new_pcm(struct snd_soc_pcm_runtime *rtd, int num)
 out:
 	dev_info(rtd->card->dev, "%s <-> %s mapping ok\n",
 		 (rtd->num_codecs > 1) ? "multicodec" : rtd->codec_dai->name,
-		 cpu_dai->name);
+		 (rtd->num_cpus > 1) ? "multicpu" : rtd->cpu_dai->name);
 	return ret;
 }