Re: [PATCH 43/49] iio:proximity:pulsedlight: Switch from CONFIG_PM guards to pm_ptr() / __maybe_unused

[Jonathan Cameron <jic23@jic23.retrosnub.co.uk>]

On Tue, 23 Nov 2021 14:22:46 -0800
Matt Ranostay <matt.ranostay@konsulko.com> wrote:

> On Tue, Nov 23, 2021 at 1:07 PM Jonathan Cameron <jic23@kernel.org> wrote:
> >
> > From: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> >
> > Letting the compiler remove these functions when the kernel is built
> > without CONFIG_PM 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.
> >
> > Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
> > Cc: Matt Ranostay <matt.ranostay@konsulko.com>  
> 
> Acked-by: Matt Ranostay <matt.ranostay@konsulko.com>
A clang build (without this patch) noted that lidar_write_power() is only used
in these functions (so I got an unused function warning). 

I'll add a maybe_unused to that as well if needed (subject to the
other discussion on how to do this better).

Thanks,

Jonathan

> 
> > ---
> >  drivers/iio/proximity/pulsedlight-lidar-lite-v2.c | 10 ++++------
> >  1 file changed, 4 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> > index 27026c060ab9..6adc2a0c27cb 100644
> > --- a/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> > +++ b/drivers/iio/proximity/pulsedlight-lidar-lite-v2.c
> > @@ -338,8 +338,7 @@ static const struct of_device_id lidar_dt_ids[] = {
> >  };
> >  MODULE_DEVICE_TABLE(of, lidar_dt_ids);
> >
> > -#ifdef CONFIG_PM
> > -static int lidar_pm_runtime_suspend(struct device *dev)
> > +static __maybe_unused int lidar_pm_runtime_suspend(struct device *dev)
> >  {
> >         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> >         struct lidar_data *data = iio_priv(indio_dev);
> > @@ -347,7 +346,7 @@ static int lidar_pm_runtime_suspend(struct device *dev)
> >         return lidar_write_power(data, 0x0f);
> >  }
> >
> > -static int lidar_pm_runtime_resume(struct device *dev)
> > +static __maybe_unused int lidar_pm_runtime_resume(struct device *dev)
> >  {
> >         struct iio_dev *indio_dev = i2c_get_clientdata(to_i2c_client(dev));
> >         struct lidar_data *data = iio_priv(indio_dev);
> > @@ -358,9 +357,8 @@ static int lidar_pm_runtime_resume(struct device *dev)
> >
> >         return ret;
> >  }
> > -#endif
> >
> > -static const struct dev_pm_ops lidar_pm_ops = {
> > +static __maybe_unused const struct dev_pm_ops lidar_pm_ops = {
> >         SET_RUNTIME_PM_OPS(lidar_pm_runtime_suspend,
> >                            lidar_pm_runtime_resume, NULL)
> >  };
> > @@ -369,7 +367,7 @@ static struct i2c_driver lidar_driver = {
> >         .driver = {
> >                 .name   = LIDAR_DRV_NAME,
> >                 .of_match_table = lidar_dt_ids,
> > -               .pm     = &lidar_pm_ops,
> > +               .pm     = pm_ptr(&lidar_pm_ops),
> >         },
> >         .probe          = lidar_probe,
> >         .remove         = lidar_remove,
> > --
> > 2.34.0
> >