Re: [PATCH 6/7] iio: adc: Add support for AD7091R-8

[Dan Carpenter]

Hi,

kernel test robot noticed the following build warnings:

https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/marcelo-schmitt-analog-com/MAINTAINERS-Add-MAINTAINERS-entry-for-AD7091R/20231122-093706
base:   https://git.kernel.org/pub/scm/linux/kernel/git/jic23/iio.git togreg
patch link:    https://lore.kernel.org/r/514295a9b760b44a710425803a41decddd3e8df8.1700595310.git.marcelo.schmitt1%40gmail.com
patch subject: [PATCH 6/7] iio: adc: Add support for AD7091R-8
config: x86_64-randconfig-161-20231122 (https://download.01.org/0day-ci/archive/20231123/202311230719.KwwC9NyC-lkp@xxxxxxxxx/config)
compiler: clang version 16.0.4 (https://github.com/llvm/llvm-project.git ae42196bc493ffe877a7e3dff8be32035dea4d07)
reproduce: (https://download.01.org/0day-ci/archive/20231123/202311230719.KwwC9NyC-lkp@xxxxxxxxx/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Reported-by: Dan Carpenter <error27@xxxxxxxxx>
| Closes: https://lore.kernel.org/r/202311230719.KwwC9NyC-lkp@xxxxxxxxx/

smatch warnings:
drivers/iio/adc/ad7091r-base.c:53 ad7091r_set_mode() warn: ignoring unreachable code.

vim +53 drivers/iio/adc/ad7091r-base.c

ca69300173b642 Paul Cercueil   2019-11-15  32  static int ad7091r_set_mode(struct ad7091r_state *st, enum ad7091r_mode mode)
ca69300173b642 Paul Cercueil   2019-11-15  33  {
ca69300173b642 Paul Cercueil   2019-11-15  34  	int ret, conf;
ca69300173b642 Paul Cercueil   2019-11-15  35  
ca69300173b642 Paul Cercueil   2019-11-15  36  	switch (mode) {
ca69300173b642 Paul Cercueil   2019-11-15  37  	case AD7091R_MODE_SAMPLE:
ca69300173b642 Paul Cercueil   2019-11-15  38  		conf = 0;
ca69300173b642 Paul Cercueil   2019-11-15  39  		break;
ca69300173b642 Paul Cercueil   2019-11-15  40  	case AD7091R_MODE_COMMAND:
ca69300173b642 Paul Cercueil   2019-11-15  41  		conf = AD7091R_REG_CONF_CMD;
ca69300173b642 Paul Cercueil   2019-11-15  42  		break;
ca69300173b642 Paul Cercueil   2019-11-15  43  	case AD7091R_MODE_AUTOCYCLE:
ca69300173b642 Paul Cercueil   2019-11-15  44  		conf = AD7091R_REG_CONF_AUTO;
ca69300173b642 Paul Cercueil   2019-11-15  45  		break;
ca69300173b642 Paul Cercueil   2019-11-15  46  	default:
ca69300173b642 Paul Cercueil   2019-11-15  47  		return -EINVAL;
ca69300173b642 Paul Cercueil   2019-11-15  48  	}
ca69300173b642 Paul Cercueil   2019-11-15  49  
fccb9cf346d38a Marcelo Schmitt 2023-11-21  50  	/* AD7091R-2/4/8 don't set normal, command, autocycle modes in conf reg */
fccb9cf346d38a Marcelo Schmitt 2023-11-21  51  	if (st->chip_info->type == AD7091R5) {
fccb9cf346d38a Marcelo Schmitt 2023-11-21  52  		return 0;

I normally ignore when people add a return 0 to stub out code because
it's obviously deliberate.  But this is a patch to add support for new
hardware and it's stubbing out the existing:

	ret = regmap_update_bits()

For existing users...  It feels like if that's necessary then it should
be done in a separate commit.

ca69300173b642 Paul Cercueil   2019-11-15 @53  		ret = regmap_update_bits(st->map, AD7091R_REG_CONF,
ca69300173b642 Paul Cercueil   2019-11-15  54  					 AD7091R_REG_CONF_MODE_MASK, conf);
ca69300173b642 Paul Cercueil   2019-11-15  55  		if (ret)
ca69300173b642 Paul Cercueil   2019-11-15  56  			return ret;
fccb9cf346d38a Marcelo Schmitt 2023-11-21  57  	}
ca69300173b642 Paul Cercueil   2019-11-15  58  
ca69300173b642 Paul Cercueil   2019-11-15  59  	st->mode = mode;
ca69300173b642 Paul Cercueil   2019-11-15  60  
ca69300173b642 Paul Cercueil   2019-11-15  61  	return 0;
ca69300173b642 Paul Cercueil   2019-11-15  62  }

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