On 2019/11/3 4:15, Ladislav Michl wrote:
> On Sat, Nov 02, 2019 at 02:08:10PM +0000, Jonathan Cameron wrote:
>> On Sat, 2 Nov 2019 11:41:25 +0100
>> Ladislav Michl <ladis@xxxxxxxxxxxxxx> wrote:
>>
>>> On Fri, Nov 01, 2019 at 09:47:41PM +0800, YueHaibing wrote:
>>>> drivers/iio/accel/st_accel_core.c:1005:44: warning:
>>>> mount_matrix_ext_info defined but not used [-Wunused-const-variable=]
>>>>
>>>> Move it to ifdef to mute this warning.
>>>>
>>>> Signed-off-by: YueHaibing <yuehaibing@xxxxxxxxxx>
>>>> ---
>>>> drivers/iio/accel/st_accel_core.c | 2 ++
>>>> 1 file changed, 2 insertions(+)
>>>>
>>>> diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
>>>> index 2e37f8a..bba0717 100644
>>>> --- a/drivers/iio/accel/st_accel_core.c
>>>> +++ b/drivers/iio/accel/st_accel_core.c
>>>> @@ -1002,10 +1002,12 @@ get_mount_matrix(const struct iio_dev *indio_dev,
>>>> return adata->mount_matrix;
>>>> }
>>>>
>>>> +#ifdef CONFIG_ACPI
>>>> static const struct iio_chan_spec_ext_info mount_matrix_ext_info[] = {
>>>> IIO_MOUNT_MATRIX(IIO_SHARED_BY_ALL, get_mount_matrix),
>>>
>>> So now you do not get any warning for unused get_mount_matrix?
>>> (Then it would make more sense to put all that stuff under one ifdef
>>> and provide empty apply_acpi_orientation for non ACPI case)
>>
>> Does the __maybe_unused marking make this go away?
>>
>> I'd assume that the compiler will manage to drop this either way
>> but I guess we should check that.
>>
>> ifdef magic is always harder to read and potentially fragile in the
>> long run. Here we simply want to indicate that in some build
>> configurations we might not use this.
>
> This suggestion implies we'll get rid of CONFIG_ACPI completely, which
> seems inapproriate looking at size of apply_acpi_orientation function.
> And having both CONFIG_ACPI and __maybe_unused does not make much
> sense. I had something like that in mind (+COMPILE_TEST perhaps):
>
> diff --git a/drivers/iio/accel/st_accel_core.c b/drivers/iio/accel/st_accel_core.c
> index 2e37f8a6d8cf..0e7eac62d618 100644
> --- a/drivers/iio/accel/st_accel_core.c
> +++ b/drivers/iio/accel/st_accel_core.c
> @@ -993,6 +993,7 @@ static const struct iio_trigger_ops st_accel_trigger_ops = {
> #define ST_ACCEL_TRIGGER_OPS NULL
> #endif
>
> +#ifdef CONFIG_ACPI
> static const struct iio_mount_matrix *
> get_mount_matrix(const struct iio_dev *indio_dev,
> const struct iio_chan_spec *chan)
> @@ -1013,7 +1014,6 @@ static const struct iio_chan_spec_ext_info mount_matrix_ext_info[] = {
> static int apply_acpi_orientation(struct iio_dev *indio_dev,
> struct iio_chan_spec *channels)
> {
> -#ifdef CONFIG_ACPI
> struct st_sensor_data *adata = iio_priv(indio_dev);
> struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
> struct acpi_device *adev;
> @@ -1141,10 +1141,14 @@ static int apply_acpi_orientation(struct iio_dev *indio_dev,
> out:
> kfree(buffer.pointer);
> return ret;
> -#else /* !CONFIG_ACPI */
> +}
> +#else
> +static int apply_acpi_orientation(struct iio_dev *indio_dev,
Does this need inline?
> + struct iio_chan_spec *channels)
> +{
> return 0;
> -#endif
> }
> +#endif
>
> /*
> * st_accel_get_settings() - get sensor settings from device name
>> Thanks,
>>
>> Jonathan
>>
>>
>>>
>>>> { },
>>>> };
>>>> +#endif
>>>>
>>>> /* Read ST-specific _ONT orientation data from ACPI and generate an
>>>> * appropriate mount matrix.
>>>> --
>>>> 2.7.4
>>>>
>
> .
>
