ASoC: core - pcm mutex per rtd

In preparation for ASoC DSP support.

The new DSP core allows DSP DAIs to be dynamically re-routed at runtime
between the PCM device end (or Frontend - FE) and the physical DAI
(Backend - BE) using regular kcontrols (just like a hardware CODEC).
The DSP core therefore must be able to call PCM operations for both the
Frontend and Backend(s) DAIs at the same time.

Currently we have a global pcm_mutex that is used to serialise
the ASoC PCM operations. This patch removes the global mutex
and adds a mutex per RTD allowing the PCM operations to be reentrant and
allow control of more than one DAI at at time. e.g. a frontend DSP hw_params()
could configure multiple backend hw_params() with similar or different
hw parameters at the same time.

Also fix the naming of soc_pcm_close.

Signed-off-by: Liam Girdwood <lrg@ti.com>

1 files changed, 23 insertions, 23 deletions

diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 932711a..e629372 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -44,7 +44,6 @@
 
 #define NAME_SIZE	32
 
-static DEFINE_MUTEX(pcm_mutex);
 static DECLARE_WAIT_QUEUE_HEAD(soc_pm_waitq);
 
 #ifdef CONFIG_DEBUG_FS
@@ -526,7 +525,7 @@ static int soc_pcm_apply_symmetry(struct snd_pcm_substream *substream)
  * then initialized and any private data can be allocated. This also calls
  * startup for the cpu DAI, platform, machine and codec DAI.
  */
-static int soc_pcm_open(struct snd_pcm_substream *substream)
+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;
@@ -537,7 +536,7 @@ static int soc_pcm_open(struct snd_pcm_substream *substream)
 	struct snd_soc_dai_driver *codec_dai_drv = codec_dai->driver;
 	int ret = 0;
 
-	mutex_lock(&pcm_mutex);
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
 	/* startup the audio subsystem */
 	if (cpu_dai->driver->ops->startup) {
@@ -667,7 +666,7 @@ static int soc_pcm_open(struct snd_pcm_substream *substream)
 	cpu_dai->active++;
 	codec_dai->active++;
 	rtd->codec->active++;
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return 0;
 
 config_err:
@@ -686,7 +685,7 @@ platform_err:
 	if (cpu_dai->driver->ops->shutdown)
 		cpu_dai->driver->ops->shutdown(substream, cpu_dai);
 out:
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return ret;
 }
 
@@ -701,7 +700,7 @@ static void close_delayed_work(struct work_struct *work)
 			container_of(work, struct snd_soc_pcm_runtime, delayed_work.work);
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
 
-	mutex_lock(&pcm_mutex);
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
 	pr_debug("pop wq checking: %s status: %s waiting: %s\n",
 		 codec_dai->driver->playback.stream_name,
@@ -716,7 +715,7 @@ static void close_delayed_work(struct work_struct *work)
 			SND_SOC_DAPM_STREAM_STOP);
 	}
 
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 }
 
 /*
@@ -724,7 +723,7 @@ static void close_delayed_work(struct work_struct *work)
  * freed here. The cpu DAI, codec DAI, machine and platform are also
  * shutdown.
  */
-static int soc_codec_close(struct snd_pcm_substream *substream)
+int soc_pcm_close(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_platform *platform = rtd->platform;
@@ -732,7 +731,7 @@ static int soc_codec_close(struct snd_pcm_substream *substream)
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
 	struct snd_soc_codec *codec = rtd->codec;
 
-	mutex_lock(&pcm_mutex);
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
 	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		cpu_dai->playback_active--;
@@ -777,7 +776,7 @@ static int soc_codec_close(struct snd_pcm_substream *substream)
 			SND_SOC_DAPM_STREAM_STOP);
 	}
 
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return 0;
 }
 
@@ -786,7 +785,7 @@ static int soc_codec_close(struct snd_pcm_substream *substream)
  * rate, etc.  This function is non atomic and can be called multiple times,
  * it can refer to the runtime info.
  */
-static int soc_pcm_prepare(struct snd_pcm_substream *substream)
+int soc_pcm_prepare(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_platform *platform = rtd->platform;
@@ -794,7 +793,7 @@ static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
 	int ret = 0;
 
-	mutex_lock(&pcm_mutex);
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
 	if (rtd->dai_link->ops && rtd->dai_link->ops->prepare) {
 		ret = rtd->dai_link->ops->prepare(substream);
@@ -847,7 +846,7 @@ static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 	snd_soc_dai_digital_mute(codec_dai, 0);
 
 out:
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return ret;
 }
 
@@ -856,7 +855,7 @@ out:
  * function can also be called multiple times and can allocate buffers
  * (using snd_pcm_lib_* ). It's non-atomic.
  */
-static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
+int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 				struct snd_pcm_hw_params *params)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
@@ -865,7 +864,7 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
 	int ret = 0;
 
-	mutex_lock(&pcm_mutex);
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
 	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_params) {
 		ret = rtd->dai_link->ops->hw_params(substream, params);
@@ -905,7 +904,7 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 	rtd->rate = params_rate(params);
 
 out:
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return ret;
 
 platform_err:
@@ -920,14 +919,14 @@ codec_err:
 	if (rtd->dai_link->ops && rtd->dai_link->ops->hw_free)
 		rtd->dai_link->ops->hw_free(substream);
 
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return ret;
 }
 
 /*
  * Frees resources allocated by hw_params, can be called multiple times
  */
-static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
+int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_platform *platform = rtd->platform;
@@ -935,7 +934,7 @@ static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
 	struct snd_soc_codec *codec = rtd->codec;
 
-	mutex_lock(&pcm_mutex);
+	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
 
 	/* apply codec digital mute */
 	if (!codec->active)
@@ -956,11 +955,11 @@ static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 	if (cpu_dai->driver->ops->hw_free)
 		cpu_dai->driver->ops->hw_free(substream, cpu_dai);
 
-	mutex_unlock(&pcm_mutex);
+	mutex_unlock(&rtd->pcm_mutex);
 	return 0;
 }
 
-static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_platform *platform = rtd->platform;
@@ -993,7 +992,7 @@ static int soc_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
  * If cpu_dai, codec_dai, platform driver has the delay callback, than
  * the runtime->delay will be updated accordingly.
  */
-static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
+snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
 {
 	struct snd_soc_pcm_runtime *rtd = substream->private_data;
 	struct snd_soc_platform *platform = rtd->platform;
@@ -1023,7 +1022,7 @@ static snd_pcm_uframes_t soc_pcm_pointer(struct snd_pcm_substream *substream)
 /* ASoC PCM operations */
 static struct snd_pcm_ops soc_pcm_ops = {
 	.open		= soc_pcm_open,
-	.close		= soc_codec_close,
+	.close		= soc_pcm_close,
 	.hw_params	= soc_pcm_hw_params,
 	.hw_free	= soc_pcm_hw_free,
 	.prepare	= soc_pcm_prepare,
@@ -1579,6 +1578,7 @@ static int soc_post_component_init(struct snd_soc_card *card,
 	rtd->dev.parent = card->dev;
 	rtd->dev.release = rtd_release;
 	rtd->dev.init_name = name;
+	mutex_init(&rtd->pcm_mutex);
 	ret = device_register(&rtd->dev);
 	if (ret < 0) {
 		dev_err(card->dev,