Re: [PATCH] iio: bmi323: Drop CONFIG_PM guards around runtime functions

[Jonathan Cameron <jic23@kernel.org>]

On Tue, 10 Sep 2024 10:22:54 -0700
Nathan Chancellor <nathan@kernel.org> wrote:

> When building with clang and CONFIG_PM disabled (such as with s390), it
> warns:
> 
>   drivers/iio/imu/bmi323/bmi323_core.c:121:27: warning: variable 'bmi323_reg_savestate' is not needed and will not be emitted [-Wunneeded-internal-declaration]
>     121 | static const unsigned int bmi323_reg_savestate[] = {
>         |                           ^~~~~~~~~~~~~~~~~~~~
>   drivers/iio/imu/bmi323/bmi323_core.c:133:27: warning: variable 'bmi323_ext_reg_savestate' is not needed and will not be emitted [-Wunneeded-internal-declaration]
>     133 | static const unsigned int bmi323_ext_reg_savestate[] = {
>         |                           ^~~~~~~~~~~~~~~~~~~~~~~~
> 
> These arrays have no references outside of sizeof(), which will be
> evaluated at compile time. To avoid these warnings, remove the CONFIG_PM
> ifdef guard and use the RUNTIME_PM_OPS macro to ensure these functions
> always appear used to the compiler, which allows the references to the
> arrays to be visible as well. This results in no difference in runtime
> behavior because bmi323_core_pm_ops is only used when CONFIG_PM is set
> with the pm_ptr() macro.
> 
> Fixes: b09999ee1e86 ("iio: bmi323: suspend and resume triggering on relevant pm operations")
> Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Applied to the fixes togreg branch of iio.git.
I'll rebase that tree on rc1 once available then send a pull request with this
in.

Thanks,

Jonathan

> ---
> NOTE: The second warning will still be visible without this change as
> well:
> 
> https://lore.kernel.org/20240909-iio-bmi323-fix-array-ref-v1-1-51c220f22229@kernel.org/
> 
> Technically, the blamed change for that fix is somewhat responsible for
> this issue as well but I believe the one I assigned was the real culprit
> because this diff should have been in that change.
> ---
>  drivers/iio/imu/bmi323/bmi323_core.c | 7 ++-----
>  1 file changed, 2 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/iio/imu/bmi323/bmi323_core.c b/drivers/iio/imu/bmi323/bmi323_core.c
> index 671401ce80dcf947b7b64ea3af112d2a42ca5501..1d1405d37c5adb2717fc27d6b22540da50dea6d4 100644
> --- a/drivers/iio/imu/bmi323/bmi323_core.c
> +++ b/drivers/iio/imu/bmi323/bmi323_core.c
> @@ -2172,7 +2172,6 @@ int bmi323_core_probe(struct device *dev)
>  }
>  EXPORT_SYMBOL_NS_GPL(bmi323_core_probe, IIO_BMI323);
>  
> -#if defined(CONFIG_PM)
>  static int bmi323_core_runtime_suspend(struct device *dev)
>  {
>  	struct iio_dev *indio_dev = dev_get_drvdata(dev);
> @@ -2293,11 +2292,9 @@ static int bmi323_core_runtime_resume(struct device *dev)
>  	return iio_device_resume_triggering(indio_dev);
>  }
>  
> -#endif
> -
>  const struct dev_pm_ops bmi323_core_pm_ops = {
> -	SET_RUNTIME_PM_OPS(bmi323_core_runtime_suspend,
> -			   bmi323_core_runtime_resume, NULL)
> +	RUNTIME_PM_OPS(bmi323_core_runtime_suspend,
> +		       bmi323_core_runtime_resume, NULL)
>  };
>  EXPORT_SYMBOL_NS_GPL(bmi323_core_pm_ops, IIO_BMI323);
>  
> 
> ---
> base-commit: 5ba0cb92584ba5e107c97001e09013c1da0772a8
> change-id: 20240910-iio-bmi323-remove-config_pm-guards-5707958e0ac1
> 
> Best regards,