Re: [PATCH] iio: bmi323: mark bmi323_ext_reg_savestate as maybe unused

[Javier Carrasco]

On 12/10/2024 11:11, Julia Lawall wrote:
> 
> 
> On Sat, 12 Oct 2024, Su Hui wrote:
> 
>> When running 'make CC=clang drivers/iio/imu/bmi323/bmi323_core.o', there
>> is a clang warning as follows:
>>
>> drivers/iio/imu/bmi323/bmi323_core.c:133:27: error:
>> variable 'bmi323_ext_reg_savestate' is not needed and will not be emitted
>> [-Werror,-Wunneeded-internal-declaration]
>>   133 | static const unsigned int bmi323_ext_reg_savestate[] = {
>>       |                           ^~~~~~~~~~~~~~~~~~~~~~~~
>> 1 error generated.
>>
>> Mark bmi323_ext_reg_savestate as __maybe_unused to silent this warning.
> 
> Why might it be unused?
> 
> julia
> 
>>
>> Fixes: 16531118ba63 ("iio: bmi323: peripheral in lowest power state on suspend")
>> Signed-off-by: Su Hui <suhui@xxxxxxxxxxxx>
>> ---
>>  drivers/iio/imu/bmi323/bmi323_core.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/iio/imu/bmi323/bmi323_core.c b/drivers/iio/imu/bmi323/bmi323_core.c
>> index beda8d2de53f..1167984809c5 100644
>> --- a/drivers/iio/imu/bmi323/bmi323_core.c
>> +++ b/drivers/iio/imu/bmi323/bmi323_core.c
>> @@ -130,7 +130,7 @@ static const unsigned int bmi323_reg_savestate[] = {
>>  	BMI323_FIFO_CONF_REG
>>  };
>>
>> -static const unsigned int bmi323_ext_reg_savestate[] = {
>> +static const unsigned int bmi323_ext_reg_savestate[] __maybe_unused = {
>>  	BMI323_GEN_SET1_REG,
>>  	BMI323_TAP1_REG,
>>  	BMI323_TAP2_REG,
>> --
>> 2.30.2
>>
>>
>>
> 

This issue has already been found and discussed here:

https://lore.kernel.org/linux-iio/AS8PR02MB10217F8B5827B69E6438488679C762@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/

where I got lectured by Nathan Chancellor about such warnings.

The fix was not marking the array as unused, because it should have been
used. The proper fix can be found in iio/fixes-togreg.

Best regards,
Javier Carrasco