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.
Oh , I just saw this email. Thanks! Su Hui
