[alsa-devel] [PATCH V2] ASoC: fsl_audmix: Add spin lock to protect tdms

[Daniel Baluta]

On Mon, Nov 11, 2019 at 9:53 AM Shengjiu Wang <shengjiu.wang at nxp.com> 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.
>
> Fixes: be1df61cf06e ("ASoC: fsl: Add Audio Mixer CPU DAI driver")
> Cc: <stable at vger.kernel.org>
> Signed-off-by: Shengjiu Wang <shengjiu.wang at nxp.com>
> Acked-by: Nicolin Chen <nicoleotsuka at gmail.com>

Reviewed-by: Daniel Baluta <daniel.baluta at nxp.com>

> ---
> Change in v2
> -add Fixes, Cc stable, and Acked-by.
>
>  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
>
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