ASoC: core: Move pcm_mutex up to card level from snd_soc_pcm_runtime

The pcm_mutex is used to prevent concurrent execution of snd_pcm_ops
callbacks. This works fine most of the cases but it can not handle setups
when the same DAI is used by different rtd, for example:
pcm3168a have two DAIs: one for Playback and one for Capture.
If the codec is connected to a single CPU DAI we need to have two dai_link
to support both playback and capture.

In this case the snd_pcm_ops callbacks can be executed in parallel causing
unexpected races in DAI drivers.

By moving the pcm_mutex up to card level this can be solved
while - hopefully - not breaking other setups.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>

include/sound/soc.h

@@ -1021,6 +1021,10 @@ struct snd_soc_card {
 	struct mutex mutex;
 	struct mutex dapm_mutex;
 
+	/* Mutex for PCM operations */
+	struct mutex pcm_mutex;
+	enum snd_soc_pcm_subclass pcm_subclass;
+
 	int id_hint;
 	bool instantiated;
 	bool topology_shortname_created;
@@ -1121,8 +1125,6 @@ struct snd_soc_pcm_runtime {
 	struct device *dev;
 	struct snd_soc_card *card;
 	struct snd_soc_dai_link *dai_link;
-	struct mutex pcm_mutex;
-	enum snd_soc_pcm_subclass pcm_subclass;
 	struct snd_pcm_ops ops;
 
 	/* Dynamic PCM BE runtime data */

sound/soc/soc-compress.c

@@ -80,7 +80,7 @@ static int soc_compr_open(struct snd_compr_stream *cstream)
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->startup) {
 		ret = cpu_dai->driver->cops->startup(cstream, cpu_dai);
@@ -108,7 +108,7 @@ static int soc_compr_open(struct snd_compr_stream *cstream)
 
 	snd_soc_runtime_activate(rtd, cstream->direction);
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 
 	return 0;
 
@@ -118,7 +118,7 @@ machine_err:
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->shutdown)
 		cpu_dai->driver->cops->shutdown(cstream, cpu_dai);
 out:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -224,7 +224,7 @@ 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_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	dev_dbg(rtd->dev,
 		"Compress ASoC: pop wq checking: %s status: %s waiting: %s\n",
@@ -239,7 +239,7 @@ static void close_delayed_work(struct work_struct *work)
 					  SND_SOC_DAPM_STREAM_STOP);
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 }
 
 static int soc_compr_free(struct snd_compr_stream *cstream)
@@ -249,7 +249,7 @@ static int soc_compr_free(struct snd_compr_stream *cstream)
 	struct snd_soc_dai *codec_dai = rtd->codec_dai;
 	int stream;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	if (cstream->direction == SND_COMPRESS_PLAYBACK)
 		stream = SNDRV_PCM_STREAM_PLAYBACK;
@@ -292,7 +292,7 @@ static int soc_compr_free(struct snd_compr_stream *cstream)
 					  SND_SOC_DAPM_STREAM_STOP);
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return 0;
 }
 
@@ -355,7 +355,7 @@ static int soc_compr_trigger(struct snd_compr_stream *cstream, int cmd)
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int ret = 0, __ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
@@ -384,7 +384,7 @@ static int soc_compr_trigger(struct snd_compr_stream *cstream, int cmd)
 	}
 
 out:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -474,7 +474,7 @@ static int soc_compr_set_params(struct snd_compr_stream *cstream,
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int ret = 0, __ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	/*
 	 * First we call set_params for the CPU DAI, then the component
@@ -518,14 +518,14 @@ static int soc_compr_set_params(struct snd_compr_stream *cstream,
 
 	/* cancel any delayed stream shutdown that is pending */
 	rtd->pop_wait = 0;
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 
 	cancel_delayed_work_sync(&rtd->delayed_work);
 
 	return ret;
 
 err:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -609,7 +609,7 @@ static int soc_compr_get_params(struct snd_compr_stream *cstream,
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int ret = 0, __ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->get_params) {
 		ret = cpu_dai->driver->cops->get_params(cstream, params, cpu_dai);
@@ -630,7 +630,7 @@ static int soc_compr_get_params(struct snd_compr_stream *cstream,
 	}
 
 err:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -642,7 +642,7 @@ static int soc_compr_get_caps(struct snd_compr_stream *cstream,
 	struct snd_soc_rtdcom_list *rtdcom;
 	int ret = 0, __ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
@@ -656,7 +656,7 @@ static int soc_compr_get_caps(struct snd_compr_stream *cstream,
 			ret = __ret;
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -668,7 +668,7 @@ static int soc_compr_get_codec_caps(struct snd_compr_stream *cstream,
 	struct snd_soc_rtdcom_list *rtdcom;
 	int ret = 0, __ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
@@ -682,7 +682,7 @@ static int soc_compr_get_codec_caps(struct snd_compr_stream *cstream,
 			ret = __ret;
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -694,7 +694,7 @@ static int soc_compr_ack(struct snd_compr_stream *cstream, size_t bytes)
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int ret = 0, __ret;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->ack) {
 		ret = cpu_dai->driver->cops->ack(cstream, bytes, cpu_dai);
@@ -715,7 +715,7 @@ static int soc_compr_ack(struct snd_compr_stream *cstream, size_t bytes)
 	}
 
 err:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -728,7 +728,7 @@ static int soc_compr_pointer(struct snd_compr_stream *cstream,
 	int ret = 0, __ret;
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	if (cpu_dai->driver->cops && cpu_dai->driver->cops->pointer)
 		cpu_dai->driver->cops->pointer(cstream, tstamp, cpu_dai);
@@ -745,7 +745,7 @@ static int soc_compr_pointer(struct snd_compr_stream *cstream,
 			ret = __ret;
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -757,7 +757,7 @@ static int soc_compr_copy(struct snd_compr_stream *cstream,
 	struct snd_soc_rtdcom_list *rtdcom;
 	int ret = 0;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
@@ -770,7 +770,7 @@ static int soc_compr_copy(struct snd_compr_stream *cstream,
 		break;
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 

sound/soc/soc-core.c

@@ -1352,7 +1352,6 @@ static int soc_post_component_init(struct snd_soc_pcm_runtime *rtd,
 	rtd->dev->groups = soc_dev_attr_groups;
 	dev_set_name(rtd->dev, "%s", name);
 	dev_set_drvdata(rtd->dev, rtd);
-	mutex_init(&rtd->pcm_mutex);
 	INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_PLAYBACK].be_clients);
 	INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_CAPTURE].be_clients);
 	INIT_LIST_HEAD(&rtd->dpcm[SNDRV_PCM_STREAM_PLAYBACK].fe_clients);
@@ -2743,6 +2742,7 @@ int snd_soc_register_card(struct snd_soc_card *card)
 	card->instantiated = 0;
 	mutex_init(&card->mutex);
 	mutex_init(&card->dapm_mutex);
+	mutex_init(&card->pcm_mutex);
 
 	ret = snd_soc_instantiate_card(card);
 	if (ret != 0)

sound/soc/soc-pcm.c

@@ -54,14 +54,14 @@ static bool snd_soc_dai_stream_valid(struct snd_soc_dai *dai, int stream)
  * Increments the active count for all the DAIs and components attached to a PCM
  * runtime. Should typically be called when a stream is opened.
  *
- * Must be called with the rtd->pcm_mutex being held
+ * Must be called with the rtd->card->pcm_mutex being held
  */
 void snd_soc_runtime_activate(struct snd_soc_pcm_runtime *rtd, int stream)
 {
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int i;
 
-	lockdep_assert_held(&rtd->pcm_mutex);
+	lockdep_assert_held(&rtd->card->pcm_mutex);
 
 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		cpu_dai->playback_active++;
@@ -89,14 +89,14 @@ void snd_soc_runtime_activate(struct snd_soc_pcm_runtime *rtd, int stream)
  * Decrements the active count for all the DAIs and components attached to a PCM
  * runtime. Should typically be called when a stream is closed.
  *
- * Must be called with the rtd->pcm_mutex being held
+ * Must be called with the rtd->card->pcm_mutex being held
  */
 void snd_soc_runtime_deactivate(struct snd_soc_pcm_runtime *rtd, int stream)
 {
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int i;
 
-	lockdep_assert_held(&rtd->pcm_mutex);
+	lockdep_assert_held(&rtd->card->pcm_mutex);
 
 	if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
 		cpu_dai->playback_active--;
@@ -491,7 +491,7 @@ static int soc_pcm_open(struct snd_pcm_substream *substream)
 		pm_runtime_get_sync(component->dev);
 	}
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	/* startup the audio subsystem */
 	if (cpu_dai->driver->ops->startup) {
@@ -609,7 +609,7 @@ dynamic:
 
 	snd_soc_runtime_activate(rtd, substream->stream);
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return 0;
 
 config_err:
@@ -632,7 +632,7 @@ component_err:
 	if (cpu_dai->driver->ops->shutdown)
 		cpu_dai->driver->ops->shutdown(substream, cpu_dai);
 out:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
@@ -662,7 +662,7 @@ 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_dais[0];
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	dev_dbg(rtd->dev, "ASoC: pop wq checking: %s status: %s waiting: %s\n",
 		 codec_dai->driver->playback.stream_name,
@@ -676,7 +676,7 @@ static void close_delayed_work(struct work_struct *work)
 					  SND_SOC_DAPM_STREAM_STOP);
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 }
 
 /*
@@ -693,7 +693,7 @@ static int soc_pcm_close(struct snd_pcm_substream *substream)
 	struct snd_soc_dai *codec_dai;
 	int i;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	snd_soc_runtime_deactivate(rtd, substream->stream);
 
@@ -742,7 +742,7 @@ static int soc_pcm_close(struct snd_pcm_substream *substream)
 					  SND_SOC_DAPM_STREAM_STOP);
 	}
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 
 	for_each_rtdcom(rtd, rtdcom) {
 		component = rtdcom->component;
@@ -775,7 +775,7 @@ static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 	struct snd_soc_dai *codec_dai;
 	int i, ret = 0;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 
 	if (rtd->dai_link->ops->prepare) {
 		ret = rtd->dai_link->ops->prepare(substream);
@@ -840,7 +840,7 @@ static int soc_pcm_prepare(struct snd_pcm_substream *substream)
 	snd_soc_dai_digital_mute(cpu_dai, 0, substream->stream);
 
 out:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -922,7 +922,7 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *cpu_dai = rtd->cpu_dai;
 	int i, ret = 0;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	mutex_lock_nested(&rtd->card->pcm_mutex, rtd->card->pcm_subclass);
 	if (rtd->dai_link->ops->hw_params) {
 		ret = rtd->dai_link->ops->hw_params(substream, params);
 		if (ret < 0) {
@@ -1008,7 +1008,7 @@ static int soc_pcm_hw_params(struct snd_pcm_substream *substream,
         if (ret)
 		goto component_err;
 out:
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 
 component_err:
@@ -1031,7 +1031,7 @@ codec_err:
 	if (rtd->dai_link->ops->hw_free)
 		rtd->dai_link->ops->hw_free(substream);
 
-	mutex_unlock(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return ret;
 }
 
@@ -1046,7 +1046,7 @@ static int soc_pcm_hw_free(struct snd_pcm_substream *substream)
 	bool playback = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
 	int i;
 
-	mutex_lock_nested(&rtd->pcm_mutex, rtd->pcm_subclass);
+	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) {
@@ -1089,7 +1089,7 @@ 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(&rtd->pcm_mutex);
+	mutex_unlock(&rtd->card->pcm_mutex);
 	return 0;
 }