Re: [PATCH v1 1/3] iio: st_lsm6dsx: Mark predefined constants with __maybe_unused

[Jonathan Cameron <jic23@kernel.org>]

On Mon, 16 Dec 2019 20:19:23 +0200
Andy Shevchenko <andriy.shevchenko@linux.intel.com> wrote:

> Since we put static variable to a header file it's copied to each module
> that includes the header. But not all of them are actually used it.
> 
> Mark predefined constants with __maybe_unused to calm a compiler down:
> 
> In file included from drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_i2c.c:17:
> .../st_lsm6dsx/st_lsm6dsx.h:399:28: warning: ‘st_lsm6dsx_available_scan_masks’ defined but not used [-Wunused-const-variable=]
>   399 | static const unsigned long st_lsm6dsx_available_scan_masks[] = {0x7, 0x0};
>       |                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> .../st_lsm6dsx/st_lsm6dsx.h:392:36: warning: ‘st_lsm6dsx_event’ defined but not used [-Wunused-const-variable=]
>   392 | static const struct iio_event_spec st_lsm6dsx_event = {
>       |                                    ^~~~~~~~~~~~~~~~
> ...
> 
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Huh, I wonder we I never saw this one either locally or from the autobuilders.

Applied to the togreg branch of iio.git and pushed out as testing for the
autobuilders to have a fun Christmas poking at it ;)

Thanks,

Jonathan

> ---
>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 7 +++++--
>  1 file changed, 5 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> index dc55d7dff3eb..b3fbbae81955 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> @@ -389,14 +389,17 @@ struct st_lsm6dsx_hw {
>  	const struct st_lsm6dsx_settings *settings;
>  };
>  
> -static const struct iio_event_spec st_lsm6dsx_event = {
> +static __maybe_unused const struct iio_event_spec st_lsm6dsx_event = {
>  	.type = IIO_EV_TYPE_THRESH,
>  	.dir = IIO_EV_DIR_EITHER,
>  	.mask_separate = BIT(IIO_EV_INFO_VALUE) |
>  			 BIT(IIO_EV_INFO_ENABLE)
>  };
>  
> -static const unsigned long st_lsm6dsx_available_scan_masks[] = {0x7, 0x0};
> +static __maybe_unused const unsigned long st_lsm6dsx_available_scan_masks[] = {
> +	0x7, 0x0,
> +};
> +
>  extern const struct dev_pm_ops st_lsm6dsx_pm_ops;
>  
>  int st_lsm6dsx_probe(struct device *dev, int irq, int hw_id,