Re: Re: [PATCH] ASoC: codecs: Fix rumtime PM imbalance in tas2552_probe

From: dinghao . liu
Date: Thu Apr 08 2021 - 01:44:35 EST


> On Wed, Apr 07, 2021 at 02:54:00PM +0800, Dinghao Liu wrote:
>
> > - pm_runtime_set_active(&client->dev);
> > - pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> > - pm_runtime_use_autosuspend(&client->dev);
> > - pm_runtime_enable(&client->dev);
> > - pm_runtime_mark_last_busy(&client->dev);
> > - pm_runtime_put_sync_autosuspend(&client->dev);
> > -
> > dev_set_drvdata(&client->dev, data);
> >
> > ret = devm_snd_soc_register_component(&client->dev,
> > @@ -733,6 +726,13 @@ static int tas2552_probe(struct i2c_client *client,
> > if (ret < 0)
> > dev_err(&client->dev, "Failed to register component: %d\n", ret);
> >
> > + pm_runtime_set_active(&client->dev);
> > + pm_runtime_set_autosuspend_delay(&client->dev, 1000);
> > + pm_runtime_use_autosuspend(&client->dev);
>
> It's not clear to me that just moving the operations after the
> registration is a good fix - once the component is registered we could
> start trying to do runtime PM operations with it which AFAIR won't count
> references and so on properly if runtime PM isn't enabled so if we later
> enable runtime PM we might have the rest of the code in a confused state
> about what's going on.

Thanks for your advice. I checked the use of devm_snd_soc_register_component()
in the kernel and found sometimes runtime PM is enabled before registration
and sometimes after registration. To be on the safe side, I will send a new
patch to fix this in error handling path.

Regards,
Dinghao