There is no need for a DPCM-specific lock at the card level, we can
use the FE-specific PCM lock instead. In addition, these PCM locks will
rely on either a spin-lock or a mutex depending on atomicity.
Since the FE PCM lock is already taken during the trigger, new
_locked versions of the helpers snd_soc_dpcm_can_be_free_stop() and
snd_soc_dpcm_check_state() are introduced. Without these changes a
conceptual deadlock happens on TRIGGER_STOP.
Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
---
include/sound/soc.h | 2 --
sound/soc/soc-core.c | 1 -
sound/soc/soc-pcm.c | 55 +++++++++++++++++++++++++++++++++++---------
3 files changed, 44 insertions(+), 14 deletions(-)
diff --git a/include/sound/soc.h b/include/sound/soc.h
index 8e6dd8a257c5..5872a8864f3b 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -893,8 +893,6 @@ struct snd_soc_card {
struct mutex pcm_mutex;
enum snd_soc_pcm_subclass pcm_subclass;
- spinlock_t dpcm_lock;
-
int (*probe)(struct snd_soc_card *card);
int (*late_probe)(struct snd_soc_card *card);
int (*remove)(struct snd_soc_card *card);
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 80ca260595fd..b029e07ad1e1 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -2339,7 +2339,6 @@ int snd_soc_register_card(struct snd_soc_card *card)
mutex_init(&card->mutex);
mutex_init(&card->dapm_mutex);
mutex_init(&card->pcm_mutex);
- spin_lock_init(&card->dpcm_lock);
return snd_soc_bind_card(card);
}
diff --git a/sound/soc/soc-pcm.c b/sound/soc/soc-pcm.c
index f22bbf95319d..797f0d114c83 100644
--- a/sound/soc/soc-pcm.c
+++ b/sound/soc/soc-pcm.c
@@ -31,13 +31,13 @@
void snd_soc_dpcm_fe_lock_irq(struct snd_soc_pcm_runtime *fe, int stream)
{
- spin_lock_irq(&fe->card->dpcm_lock);
+ snd_pcm_stream_lock_irq(snd_soc_dpcm_get_substream(fe, stream));
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_lock_irq);
void snd_soc_dpcm_fe_unlock_irq(struct snd_soc_pcm_runtime *fe, int stream)
{
- spin_unlock_irq(&fe->card->dpcm_lock);
+ snd_pcm_stream_unlock_irq(snd_soc_dpcm_get_substream(fe, stream));
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_unlock_irq);
@@ -45,6 +45,9 @@ EXPORT_SYMBOL_GPL(snd_soc_dpcm_fe_unlock_irq);
static int snd_soc_dpcm_can_be_free_stop(struct snd_soc_pcm_runtime *fe,
struct snd_soc_pcm_runtime *be, int stream);
+static int snd_soc_dpcm_can_be_free_stop_locked(struct snd_soc_pcm_runtime *fe,
+ struct snd_soc_pcm_runtime *be, int stream);
+
/* can this BE perform a hw_params() */
static int snd_soc_dpcm_can_be_params(struct snd_soc_pcm_runtime *fe,
struct snd_soc_pcm_runtime *be, int stream);
@@ -2101,7 +2104,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
(be->dpcm[stream].state != SND_SOC_DPCM_STATE_PAUSED))
continue;
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
+ if (!snd_soc_dpcm_can_be_free_stop_locked(fe, be, stream))
continue;
ret = soc_pcm_trigger(be_substream, cmd);
@@ -2114,7 +2117,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
continue;
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
+ if (!snd_soc_dpcm_can_be_free_stop_locked(fe, be, stream))
continue;
ret = soc_pcm_trigger(be_substream, cmd);
@@ -2127,7 +2130,7 @@ int dpcm_be_dai_trigger(struct snd_soc_pcm_runtime *fe, int stream,
if (be->dpcm[stream].state != SND_SOC_DPCM_STATE_START)
continue;
- if (!snd_soc_dpcm_can_be_free_stop(fe, be, stream))
+ if (!snd_soc_dpcm_can_be_free_stop_locked(fe, be, stream))
continue;
ret = soc_pcm_trigger(be_substream, cmd);
@@ -2873,18 +2876,17 @@ struct snd_pcm_substream *
}
EXPORT_SYMBOL_GPL(snd_soc_dpcm_get_substream);
-static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe,
- struct snd_soc_pcm_runtime *be,
- int stream,
- const enum snd_soc_dpcm_state *states,
- int num_states)
+static int snd_soc_dpcm_check_state_locked(struct snd_soc_pcm_runtime *fe,
+ struct snd_soc_pcm_runtime *be,
+ int stream,
+ const enum snd_soc_dpcm_state *states,
+ int num_states)
{
struct snd_soc_dpcm *dpcm;
int state;
int ret = 1;
int i;
- snd_soc_dpcm_fe_lock_irq(fe, stream);
for_each_dpcm_fe(be, stream, dpcm) {
if (dpcm->fe == fe)
@@ -2898,12 +2900,43 @@ static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe,
}
}
}
+
+ /* it's safe to do this BE DAI */
+ return ret;
+}
+
+static int snd_soc_dpcm_check_state(struct snd_soc_pcm_runtime *fe,
+ struct snd_soc_pcm_runtime *be,
+ int stream,
+ const enum snd_soc_dpcm_state *states,
+ int num_states)
+{
+ int ret;
+
+ snd_soc_dpcm_fe_lock_irq(fe, stream);
+ ret = snd_soc_dpcm_check_state_locked(fe, be, stream, states, num_states);
snd_soc_dpcm_fe_unlock_irq(fe, stream);
/* it's safe to do this BE DAI */
return ret;
}
+/*
+ * We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE
+ * are not running, paused or suspended for the specified stream direction.
+ */
+static int snd_soc_dpcm_can_be_free_stop_locked(struct snd_soc_pcm_runtime *fe,
+ struct snd_soc_pcm_runtime *be, int stream)
+{
+ const enum snd_soc_dpcm_state state[] = {
+ SND_SOC_DPCM_STATE_START,
+ SND_SOC_DPCM_STATE_PAUSED,
+ SND_SOC_DPCM_STATE_SUSPEND,
+ };
+
+ return snd_soc_dpcm_check_state_locked(fe, be, stream, state, ARRAY_SIZE(state));
+}
+
/*
* We can only hw_free, stop, pause or suspend a BE DAI if any of it's FE
* are not running, paused or suspended for the specified stream direction.
--
2.25.1
