Re: [PATCH v2 7/9] ASoC: codecs: Add support for the generic IIO auxiliary devices

[Herve Codina]

Hi Andy,

On Tue, 6 Jun 2023 15:54:04 +0200
Herve Codina <herve.codina@xxxxxxxxxxx> wrote:

...
> >   
> > > +	platform_set_drvdata(pdev, iio_aux);    
> > 
> > Which callback is using this driver data?  
> 
> None -> I will remove platform_set_drvdata().
> 

My previous answer was not correct.
The platform_set_drvdata() call is needed.

In fact, the driver uses snd_soc_component_get_drvdata() 
  https://elixir.bootlin.com/linux/v6.4-rc5/source/include/sound/soc-component.h#L425
and this snd_soc_component_get_drvdata() get the driver data set by the
platform_set_drvdata() call.

I cannot use snd_soc_component_set_drvdata() to set the driver data because
I haven't got the struct snd_soc_component instance when I need to set the
driver data.

So, I will not remove the platform_set_drvdata() call.

The sequence is:
  --- 8< ---
  static int audio_iio_aux_probe(struct platform_device *pdev)
  {
	struct audio_iio_aux *iio_aux;

	iio_aux = devm_kzalloc(&pdev->dev, sizeof(*iio_aux), GFP_KERNEL);
	if (!iio_aux)
		return -ENOMEM;

	...

	platform_set_drvdata(pdev, iio_aux);

	return devm_snd_soc_register_component(iio_aux->dev,
					       &audio_iio_aux_component_driver,
					       NULL, 0);
  }
  --- 8< ---

The struct snd_soc_component instance will be create during the 
devm_snd_soc_register_component() call.

Regards,
Hervé

-- 
Hervé Codina, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com