Re: [alsa-devel] [PATCH] ASoC: fsl_audmix: Add spin lock to protect tdms

On Wed, Nov 06, 2019 at 03:27:45PM +0800, Shengjiu Wang wrote:

Audmix support two substream, When two substream start to run, the trigger function may be called by two substream in same time, that the priv->tdms may be updated wrongly.

The expected priv->tdms is 0x3, but sometimes the result is 0x2, or 0x1.

Feels like a bug fix to me, so might be better to have a "Fixes" line and CC stable tree?

Anyway, change looks good to me:

Acked-by: Nicolin Chen nicoleotsuka@gmail.com

Thanks

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

sound/soc/fsl/fsl_audmix.c | 6 ++++++ sound/soc/fsl/fsl_audmix.h | 1 + 2 files changed, 7 insertions(+)

diff --git a/sound/soc/fsl/fsl_audmix.c b/sound/soc/fsl/fsl_audmix.c index c7e4e9757dce..a1db1bce330f 100644 --- a/sound/soc/fsl/fsl_audmix.c +++ b/sound/soc/fsl/fsl_audmix.c @@ -286,6 +286,7 @@ static int fsl_audmix_dai_trigger(struct snd_pcm_substream *substream, int cmd, struct snd_soc_dai *dai) { struct fsl_audmix *priv = snd_soc_dai_get_drvdata(dai);

• unsigned long lock_flags;

  /* Capture stream shall not be handled */ if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)

@@ -295,12 +296,16 @@ static int fsl_audmix_dai_trigger(struct snd_pcm_substream *substream, int cmd, case SNDRV_PCM_TRIGGER_START: case SNDRV_PCM_TRIGGER_RESUME: case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:

• spin_lock_irqsave(&priv->lock, lock_flags);
  

  priv->tdms |= BIT(dai->driver->id);

• spin_unlock_irqrestore(&priv->lock, lock_flags);
  

  break; case SNDRV_PCM_TRIGGER_STOP: case SNDRV_PCM_TRIGGER_SUSPEND: case SNDRV_PCM_TRIGGER_PAUSE_PUSH:

• spin_lock_irqsave(&priv->lock, lock_flags);
  

  priv->tdms &= ~BIT(dai->driver->id);

• spin_unlock_irqrestore(&priv->lock, lock_flags);
  

  break; default: return -EINVAL;

@@ -491,6 +496,7 @@ static int fsl_audmix_probe(struct platform_device *pdev) return PTR_ERR(priv->ipg_clk); }

• spin_lock_init(&priv->lock); platform_set_drvdata(pdev, priv); pm_runtime_enable(dev);

diff --git a/sound/soc/fsl/fsl_audmix.h b/sound/soc/fsl/fsl_audmix.h index 7812ffec45c5..479f05695d53 100644 --- a/sound/soc/fsl/fsl_audmix.h +++ b/sound/soc/fsl/fsl_audmix.h @@ -96,6 +96,7 @@ struct fsl_audmix { struct platform_device *pdev; struct regmap *regmap; struct clk *ipg_clk;

• spinlock_t lock; /* Protect tdms */ u8 tdms;

};

-- 2.21.0