Re: [PATCH] ASoC: meson: gx-formatter: change stream lock from mutex to spinlock

[Martin Blumenstingl]

Hi Valerio,

On Wed, Oct 21, 2026 at 11:52 PM Valerio Setti <vsetti@xxxxxxxxxxxx> wrote:
[...]
> @@ -85,9 +85,9 @@ static void gx_formatter_detach(struct gx_formatter *formatter)
>         if (!ts)
>                 return;
>
> -       mutex_lock(&ts->lock);
> +       spin_lock_irq(&ts->lock);
>         list_del(&formatter->list);
> -       mutex_unlock(&ts->lock);
> +       spin_unlock_irq(&ts->lock);
>
>         gx_formatter_disable(formatter);
The documentation below states that ->ops->disable is called with the lock held.
gx_stream_stop() does call it with the locks held but
gx_formatter_detach here doesn't.

It doesn't seem to be problematic yet because aiu-formatter-i2s.c
doesn't register a ->disable callback.
Can you please still look into whether this is a problem?

Also for a future patch (not this bugfix anymore) it would be great to
have lockdep_assert_held validate that the lock has been taken (inside
->enable, ->disable and ->prepare).

[...]
>  struct gx_formatter_ops {
>         struct gx_stream *(*get_stream)(struct snd_soc_dapm_widget *w);
> +       /*
> +        * Following functions are called with gx_stream->lock held and local
> +        * IRQs disabled so they must not sleep.
> +        */
>         void (*enable)(struct regmap *map);
>         void (*disable)(struct regmap *map);
>         int (*prepare)(struct regmap *map,


Thank you and best regards,
Martin