Re: [PATCH 13/49] iio:adc:at91-adc: Switch from CONFIG_PM_SLEEP guards to pm_ptr() / __maybe_unused

[Alexandre Belloni <alexandre.belloni@bootlin.com>]

On 23/11/2021 21:09:43+0000, Jonathan Cameron wrote:
> From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> 
> Letting the compiler remove these functions when the kernel is built
> without CONFIG_PM_SLEEP support is simpler and less error prone than the
> use of ifdef based config guards.
> 
> Removing instances of this approach from IIO also stops them being
> copied into new drivers.
> 
> The pm_ptr() macro only removes the reference if CONFIG_PM is not
> set. It is possible for CONFIG_PM=y without CONFIG_SLEEP, so this
> will not always remove the pm_ops structure.
> 
> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

> Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
> Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
> ---
>  drivers/iio/adc/at91_adc.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
> index 5a7d3a3a5fa8..14a4735d72b5 100644
> --- a/drivers/iio/adc/at91_adc.c
> +++ b/drivers/iio/adc/at91_adc.c
> @@ -1234,8 +1234,7 @@ static int at91_adc_remove(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -#ifdef CONFIG_PM_SLEEP
> -static int at91_adc_suspend(struct device *dev)
> +static __maybe_unused int at91_adc_suspend(struct device *dev)
>  {
>  	struct iio_dev *idev = dev_get_drvdata(dev);
>  	struct at91_adc_state *st = iio_priv(idev);
> @@ -1246,7 +1245,7 @@ static int at91_adc_suspend(struct device *dev)
>  	return 0;
>  }
>  
> -static int at91_adc_resume(struct device *dev)
> +static __maybe_unused int at91_adc_resume(struct device *dev)
>  {
>  	struct iio_dev *idev = dev_get_drvdata(dev);
>  	struct at91_adc_state *st = iio_priv(idev);
> @@ -1256,7 +1255,6 @@ static int at91_adc_resume(struct device *dev)
>  
>  	return 0;
>  }
> -#endif
>  
>  static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
>  
> @@ -1386,7 +1384,7 @@ static struct platform_driver at91_adc_driver = {
>  	.driver = {
>  		   .name = DRIVER_NAME,
>  		   .of_match_table = at91_adc_dt_ids,
> -		   .pm = &at91_adc_pm_ops,
> +		   .pm = pm_ptr(&at91_adc_pm_ops),
>  	},
>  };
>  
> -- 
> 2.34.0
> 

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com