[PATCH AUTOSEL 5.0 19/79] ASoC: stm32: dfsdm: manage multiple prepare

Sasha Levin
2019-04-27T01:55:51Z

From: Olivier Moysan <olivier.moysan@st.com>

[ Upstream commit 19441e35a43b616ea6afad91ed0d9e77268d8f6a ]

The DFSDM must be stopped when a new setting is applied.
restart systematically DFSDM on multiple prepare calls,
to apply changes.

Signed-off-by: Olivier Moysan <olivier.moysan@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
sound/soc/stm/stm32_adfsdm.c | 17 ++++++++++++++++-
1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/sound/soc/stm/stm32_adfsdm.c b/sound/soc/stm/stm32_adfsdm.c
index 706ff005234f..71d341b732a4 100644
--- a/sound/soc/stm/stm32_adfsdm.c
+++ b/sound/soc/stm/stm32_adfsdm.c
@@ -9,6 +9,7 @@

#include <linux/clk.h>
#include <linux/module.h>
+#include <linux/mutex.h>
#include <linux/platform_device.h>
#include <linux/slab.h>

@@ -37,6 +38,8 @@ struct stm32_adfsdm_priv {
/* PCM buffer */
unsigned char *pcm_buff;
unsigned int pos;
+
+ struct mutex lock; /* protect against race condition on iio state */
};

static const struct snd_pcm_hardware stm32_adfsdm_pcm_hw = {
@@ -62,10 +65,12 @@ static void stm32_adfsdm_shutdown(struct snd_pcm_substream *substream,
{
struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);

+ mutex_lock(&priv->lock);
if (priv->iio_active) {
iio_channel_stop_all_cb(priv->iio_cb);
priv->iio_active = false;
}
+ mutex_unlock(&priv->lock);
}

static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,
@@ -74,13 +79,19 @@ static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,
struct stm32_adfsdm_priv *priv = snd_soc_dai_get_drvdata(dai);
int ret;

+ mutex_lock(&priv->lock);
+ if (priv->iio_active) {
+ iio_channel_stop_all_cb(priv->iio_cb);
+ priv->iio_active = false;
+ }
+
ret = iio_write_channel_attribute(priv->iio_ch,
substream->runtime->rate, 0,
IIO_CHAN_INFO_SAMP_FREQ);
if (ret < 0) {
dev_err(dai->dev, "%s: Failed to set %d sampling rate\n",
__func__, substream->runtime->rate);
- return ret;
+ goto out;
}

if (!priv->iio_active) {
@@ -92,6 +103,9 @@ static int stm32_adfsdm_dai_prepare(struct snd_pcm_substream *substream,
__func__, ret);
}

+out:
+ mutex_unlock(&priv->lock);
+
return ret;
}

@@ -298,6 +312,7 @@ static int stm32_adfsdm_probe(struct platform_device *pdev)

priv->dev = &pdev->dev;
priv->dai_drv = stm32_adfsdm_dai;
+ mutex_init(&priv->lock);

dev_set_drvdata(&pdev->dev, priv);

--
2.19.1