diff mbox series

ASoC: fsl_esai: Add spin lock to protect reset and stop

Message ID 1571815789-15656-1-git-send-email-shengjiu.wang@nxp.com
State Superseded
Headers show
Series ASoC: fsl_esai: Add spin lock to protect reset and stop | expand

Commit Message

Shengjiu Wang Oct. 23, 2019, 7:29 a.m. UTC 
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.
So Add spin lock to lock these two function.

Fixes: 7ccafa2b3879 ("ASoC: fsl_esai: recover the channel swap after xrun")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>

---
 sound/soc/fsl/fsl_esai.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

-- 
2.21.0

Comments

Nicolin Chen Oct. 23, 2019, 6:31 p.m. UTC | #1 
On Wed, Oct 23, 2019 at 03:29:49PM +0800, Shengjiu Wang wrote:
> 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.


What about fsl_esai_trigger_start? It touches ESAI_xFCR_xFEN bit
that is being checked in the beginning of fsl_esai_hw_reset.

Could the scenario below be possible also?

1) ESAI TX starts
2) Xrun happens to TX
3) Starting fsl_esai_hw_reset (enabled[TX] = true; enabled[RX] = false)
4) ESAI RX starts
5) Finishing fsl_esai_hw_reset (enabled[RX] is still false)

Thanks
Nicolin

> So Add spin lock to lock these two function.

> 

> Fixes: 7ccafa2b3879 ("ASoC: fsl_esai: recover the channel swap after xrun")

> Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>

> ---

>  sound/soc/fsl/fsl_esai.c | 10 ++++++++++

>  1 file changed, 10 insertions(+)

> 

> diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c

> index 37b14c48b537..6a797648b66d 100644

> --- 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 to handle reset and stop behavior

>   * @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 reset and stop */

>  	u32 fifo_depth;

>  	u32 slot_width;

>  	u32 slots;

> @@ -676,8 +678,10 @@ static void fsl_esai_hw_reset(unsigned long arg)

>  {

>  	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 long arg)

>  		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_pcm_substream *substream, int cmd,

>  {

>  	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;

>  

> @@ -734,7 +741,9 @@ static int fsl_esai_trigger(struct snd_pcm_substream *substream, int cmd,

>  	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 +1011,7 @@ static int fsl_esai_probe(struct platform_device *pdev)

>  

>  	dev_set_drvdata(&pdev->dev, esai_priv);

>  

> +	spin_lock_init(&esai_priv->lock);

>  	ret = fsl_esai_hw_init(esai_priv);

>  	if (ret)

>  		return ret;

> -- 

> 2.21.0

>
diff mbox series

Patch

diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
index 37b14c48b537..6a797648b66d 100644
--- 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 to handle reset and stop behavior
  * @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 reset and stop */
 	u32 fifo_depth;
 	u32 slot_width;
 	u32 slots;
@@ -676,8 +678,10 @@  static void fsl_esai_hw_reset(unsigned long arg)
 {
 	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 long arg)
 		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_pcm_substream *substream, int cmd,
 {
 	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;
 
@@ -734,7 +741,9 @@  static int fsl_esai_trigger(struct snd_pcm_substream *substream, int cmd,
 	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 +1011,7 @@  static int fsl_esai_probe(struct platform_device *pdev)
 
 	dev_set_drvdata(&pdev->dev, esai_priv);
 
+	spin_lock_init(&esai_priv->lock);
 	ret = fsl_esai_hw_init(esai_priv);
 	if (ret)
 		return ret;