Re: [PATCH][RFC] ASoC: soc-component: count snd_soc_component_open/close()

[Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>]

Hi Sridharan

>     ASoC component open/close and snd_soc_component_module_get/put are
>     called once for each component, but we need it for each substream.
>     To solve this issue, this patch counts open / get,
>     and call close / put accordingly.
>
>     Fixes: dd03907bf129 ("ASoC: soc-pcm: call snd_soc_component_open/close() once")
>     Reported-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
>     Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
>     ---
(snip)
>     @@ -297,14 +297,16 @@ EXPORT_SYMBOL_GPL(snd_soc_component_set_jack);
>      int snd_soc_component_module_get(struct snd_soc_component *component,
>                                      int upon_open)
>      {
>     -       if (component->module)
>     -               return 0;
>     +       if (unlikely(component->module == 0xff)) {
>     +               dev_warn(component->dev, "too many module get (%s)\n", component->name);
>     +               return -EBUSY;
>     +       }
>
>             if (component->driver->module_get_upon_open == !!upon_open &&
>                 !try_module_get(component->dev->driver->owner))
>                     return -ENODEV;
>
>     -       component->module = 1;
>     +       component->module++;
>
> Thanks, Morimoto-san for the alternate fix. I understand the rationale for having a count for component->opened, but what is the rationale for the module count? What it is
> intended to protect?

I think same as open ?
It protects calling put() from not-get-component.
Because module_put() has WARN_ON(ret < 0).

Thank you for your help !!
Best regards
---
Kuninori Morimoto