[PATCH V2] ASoC: fsl_esai: Add spin lock to protect reset, stop and start

[Nicolin Chen]

On Fri, Oct 25, 2019 at 03:13:53PM +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.
> 
> 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 at nxp.com>

Some small comments inline. Once they are addressed, please add:

Acked-by: Nicolin Chen <nicoleotsuka at gmail.com>

Thanks

> ---
> Change in v2
> -add lock for fsl_esai_trigger_start.
> 
>  sound/soc/fsl/fsl_esai.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/sound/soc/fsl/fsl_esai.c b/sound/soc/fsl/fsl_esai.c
> index 37b14c48b537..9b28e2af26e4 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

Should be "between hw_reset() and trigger()" now.

>   * @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 */

We can drop the comments here since you add it to the top.