[PATCH 1/3] ASoC: core

* [PATCH 1/3] ASoC: core - Add card mutex locking subclasses
@ 2012-03-02 18:11 Liam Girdwood
  2012-03-02 18:11 ` [PATCH 2/3] ASoC: dapm - Use card mutex for DAPM ops instead of codec mutex Liam Girdwood
  2012-03-02 18:11 ` [PATCH 3/3] ASoC: dapm - lock mixer & mux update power with card mutex Liam Girdwood
  0 siblings, 2 replies; 10+ messages in thread
From: Liam Girdwood @ 2012-03-02 18:11 UTC (permalink / raw)
  To: Mark Brown; +Cc: alsa-devel, Liam Girdwood

This is the first part of a change that is intended to improve
ASoC locking protection for DAPM and PCM operations.

We currently use the codec->mutex for locking some DAPM operations.
This can't guarantee correctness now with the recent multi-component
and forth coming Dynamic PCM updates.

This part of the series adds a mutex class for the soc_card mutex. The
SND_SOC_CARD_CLASS_INIT class is used for card initialisation only whilst the
SND_SOC_CARD_CLASS_PCM class is used for all the DAPM and forth coming Dynamic
PCM operations. The new mutex classes are required otherwise we will see a false
positive mutex deadlock warning between the card initialisation and the DAPM
operations (something that would never deadlock in real life).

Signed-off-by: Liam Girdwood <lrg@ti.com>
---
 include/sound/soc.h  |    5 +++++
 sound/soc/soc-core.c |    2 +-
 2 files changed, 6 insertions(+), 1 deletions(-)

diff --git a/include/sound/soc.h b/include/sound/soc.h
index 82bd773..f2b5ad1 100644
--- a/include/sound/soc.h
+++ b/include/sound/soc.h
@@ -288,6 +288,11 @@ enum snd_soc_pcm_subclass {
 	SND_SOC_PCM_CLASS_BE	= 1,
 };
 
+enum snd_soc_card_subclass {
+	SND_SOC_CARD_CLASS_INIT	= 0,
+	SND_SOC_CARD_CLASS_PCM	= 1,
+};
+
 int snd_soc_codec_set_sysclk(struct snd_soc_codec *codec, int clk_id,
 			     int source, unsigned int freq, int dir);
 int snd_soc_codec_set_pll(struct snd_soc_codec *codec, int pll_id, int source,
diff --git a/sound/soc/soc-core.c b/sound/soc/soc-core.c
index 29dbbd7..2038522 100644
--- a/sound/soc/soc-core.c
+++ b/sound/soc/soc-core.c
@@ -1416,7 +1416,7 @@ static void snd_soc_instantiate_card(struct snd_soc_card *card)
 	struct snd_soc_dai_link *dai_link;
 	int ret, i, order;
 
-	mutex_lock(&card->mutex);
+	mutex_lock_nested(&card->mutex, SND_SOC_CARD_CLASS_INIT);
 
 	if (card->instantiated) {
 		mutex_unlock(&card->mutex);
-- 
1.7.5.4

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