[PATCH 5.4 057/203] ASoC: fsl_esai: Add spin lock to protect reset, stop and start

Greg Kroah-Hartman
2020-01-16T23:47:13Z

From: Shengjiu Wang <shengjiu.wang@nxp.com>

commit 35dac627471938eda89fa39ee4ead1f7667e0f57 upstream.

xrun may happen at the end of stream, the
trigger->fsl_esai_trigger_stop maybe called in the middle of
fsl_esai_hw_reset, this may cause esai in wrong state
after stop, and there may be endless xrun interrupt.

This issue may also happen with trigger->fsl_esai_trigger_start.

So Add spin lock to lock those functions.

Fixes: 7ccafa2b3879 ("ASoC: fsl_esai: recover the channel swap after xrun")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Acked-by: Nicolin Chen <nicoleotsuka@gmail.com>
Link: https://lore.kernel.org/r/52e92c4221a83e39a84a6cd92fc3d5479b44894c.1572252321.git.shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
sound/soc/fsl/fsl_esai.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

--- a/sound/soc/fsl/fsl_esai.c
+++ b/sound/soc/fsl/fsl_esai.c
@@ -33,6 +33,7 @@
* @fsysclk: system clock source to derive HCK, SCK and FS
* @spbaclk: SPBA clock (optional, depending on SoC design)
* @task: tasklet to handle the reset operation
+ * @lock: spin lock between hw_reset() and trigger()
* @fifo_depth: depth of tx/rx FIFO
* @slot_width: width of each DAI slot
* @slots: number of slots
@@ -56,6 +57,7 @@ struct fsl_esai {
struct clk *fsysclk;
struct clk *spbaclk;
struct tasklet_struct task;
+ spinlock_t lock; /* Protect hw_reset and trigger */
u32 fifo_depth;
u32 slot_width;
u32 slots;
@@ -676,8 +678,10 @@ static void fsl_esai_hw_reset(unsigned l
{
struct fsl_esai *esai_priv = (struct fsl_esai *)arg;
bool tx = true, rx = false, enabled[2];
+ unsigned long lock_flags;
u32 tfcr, rfcr;

+ spin_lock_irqsave(&esai_priv->lock, lock_flags);
/* Save the registers */
regmap_read(esai_priv->regmap, REG_ESAI_TFCR, &tfcr);
regmap_read(esai_priv->regmap, REG_ESAI_RFCR, &rfcr);
@@ -715,6 +719,8 @@ static void fsl_esai_hw_reset(unsigned l
fsl_esai_trigger_start(esai_priv, tx);
if (enabled[rx])
fsl_esai_trigger_start(esai_priv, rx);
+
+ spin_unlock_irqrestore(&esai_priv->lock, lock_flags);
}

static int fsl_esai_trigger(struct snd_pcm_substream *substream, int cmd,
@@ -722,6 +728,7 @@ static int fsl_esai_trigger(struct snd_p
{
struct fsl_esai *esai_priv = snd_soc_dai_get_drvdata(dai);
bool tx = substream->stream == SNDRV_PCM_STREAM_PLAYBACK;
+ unsigned long lock_flags;

esai_priv->channels[tx] = substream->runtime->channels;

@@ -729,12 +736,16 @@ static int fsl_esai_trigger(struct snd_p
case SNDRV_PCM_TRIGGER_START:
case SNDRV_PCM_TRIGGER_RESUME:
case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ spin_lock_irqsave(&esai_priv->lock, lock_flags);
fsl_esai_trigger_start(esai_priv, tx);
+ spin_unlock_irqrestore(&esai_priv->lock, lock_flags);
break;
case SNDRV_PCM_TRIGGER_SUSPEND:
case SNDRV_PCM_TRIGGER_STOP:
case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ spin_lock_irqsave(&esai_priv->lock, lock_flags);
fsl_esai_trigger_stop(esai_priv, tx);
+ spin_unlock_irqrestore(&esai_priv->lock, lock_flags);
break;
default:
return -EINVAL;
@@ -1002,6 +1013,7 @@ static int fsl_esai_probe(struct platfor

dev_set_drvdata(&pdev->dev, esai_priv);

+ spin_lock_init(&esai_priv->lock);
ret = fsl_esai_hw_init(esai_priv);
if (ret)
return ret;