We can have a snd_soc_dai i.e, cpu_dai and codec_dai, shared among two or more dai_links by avoiding shutting-down/powering-up if the dai is already in an appropriate state. For that, we change semantics of the snd_soc_dai.active flag from indicator to reference counter.

This patch only attempts to block duplicate startup/shutdown and the mute callbacks, presuming currently no dai driver anticipates 'dai reuse'.

Signed-off-by: Jassi Brar jassi.brar@samsung.com --- include/sound/soc.h | 2 +- sound/soc/soc-core.c | 47 ++++++++++++++++++++++++++++------------------- 2 files changed, 29 insertions(+), 20 deletions(-)

The codec->active can also be deducted by codec_dai->capture/playback.active So, we can get rid of snd_soc_codec.active field as well to reduce number of variables we have to manage in future while making delicate changes in ASoC.

diff --git a/include/sound/soc.h b/include/sound/soc.h index 27a2ad9..f792c18 100644 --- a/include/sound/soc.h +++ b/include/sound/soc.h @@ -375,7 +375,7 @@ struct snd_soc_pcm_stream { unsigned int rate_max; /* max rate */ unsigned int channels_min; /* min channels */ unsigned int channels_max; /* max channels */ - unsigned int active:1; /* stream is in use */ + unsigned int active; /* num of active users of the stream */ };

/* SoC audio ops */ diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c index 2b66719..459f1f5 100644 --- a/sound/soc/soc-core.c +++ b/sound/soc/soc-core.c @@ -352,7 +352,7 @@ static int soc_pcm_open(struct snd_pcm_substream *substream) mutex_lock(&pcm_mutex);

/* startup the audio subsystem */ - if (cpu_dai->ops->startup) { + if (cpu_dai->active == 0 && cpu_dai->ops->startup) { ret = cpu_dai->ops->startup(substream, cpu_dai); if (ret < 0) { printk(KERN_ERR "asoc: can't open interface %s\n", @@ -369,7 +369,7 @@ static int soc_pcm_open(struct snd_pcm_substream *substream) } }

- if (codec_dai->ops->startup) { + if (codec_dai->active == 0 && codec_dai->ops->startup) { ret = codec_dai->ops->startup(substream, codec_dai); if (ret < 0) { printk(KERN_ERR "asoc: can't open codec %s\n", @@ -454,11 +454,15 @@ static int soc_pcm_open(struct snd_pcm_substream *substream) pr_debug("asoc: min rate %d max rate %d\n", runtime->hw.rate_min, runtime->hw.rate_max);

- if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) - cpu_dai->playback.active = codec_dai->playback.active = 1; - else - cpu_dai->capture.active = codec_dai->capture.active = 1; - cpu_dai->active = codec_dai->active = 1; + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + cpu_dai->playback.active++; + codec_dai->playback.active++; + } else { + cpu_dai->capture.active++; + codec_dai->capture.active++; + } + cpu_dai->active++; + codec_dai->active++; card->codec->active++; mutex_unlock(&pcm_mutex); return 0; @@ -534,27 +538,28 @@ static int soc_codec_close(struct snd_pcm_substream *substream)

mutex_lock(&pcm_mutex);

- if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) - cpu_dai->playback.active = codec_dai->playback.active = 0; - else - cpu_dai->capture.active = codec_dai->capture.active = 0; - - if (codec_dai->playback.active == 0 && - codec_dai->capture.active == 0) { - cpu_dai->active = codec_dai->active = 0; + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { + cpu_dai->playback.active--; + codec_dai->playback.active--; + } else { + cpu_dai->capture.active--; + codec_dai->capture.active--; } + + cpu_dai->active--; + codec_dai->active--; codec->active--;

/* Muting the DAC suppresses artifacts caused during digital * shutdown, for example from stopping clocks. */ - if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) + if (codec_dai->active == 0 && substream->stream == SNDRV_PCM_STREAM_PLAYBACK) snd_soc_dai_digital_mute(codec_dai, 1);

- if (cpu_dai->ops->shutdown) + if (cpu_dai->active == 0 && cpu_dai->ops->shutdown) cpu_dai->ops->shutdown(substream, cpu_dai);

- if (codec_dai->ops->shutdown) + if (codec_dai->active == 0 && codec_dai->ops->shutdown) codec_dai->ops->shutdown(substream, codec_dai);

if (machine->ops && machine->ops->shutdown) @@ -563,6 +568,10 @@ static int soc_codec_close(struct snd_pcm_substream *substream) if (platform->pcm_ops->close) platform->pcm_ops->close(substream);

+ /* Skip DAPM if codec is still active via some other dai_link */ + if (codec_dai->active) + goto exit; + if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) { /* start delayed pop wq here for playback streams */ codec_dai->pop_wait = 1; @@ -574,7 +583,7 @@ static int soc_codec_close(struct snd_pcm_substream *substream) codec_dai->capture.stream_name, SND_SOC_DAPM_STREAM_STOP); } - +exit: mutex_unlock(&pcm_mutex); return 0; }