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@xxxxxxx>
> ---
> 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
>
_______________________________________________
Alsa-devel mailing list
Alsa-devel@xxxxxxxxxxxxxxxx
https://mailman.alsa-project.org/mailman/listinfo/alsa-devel
