Re: [PATCH v2 3/3] hwmon: pmbus: mpq8785: force direct mode for VID VOUT on MPQ8785/MPQ8786

[kernel test robot <lkp@intel.com>]

Hi Carl,

kernel test robot noticed the following build warnings:

[auto build test WARNING on 4c87cdd0328495759f6e9f9f4e1e53ef8032a76f]

url:    https://github.com/intel-lab-lkp/linux/commits/Carl-Lee-via-B4-Relay/dt-bindings-hwmon-pmbus-mpq8785-add-MPQ8786-support/20260205-180428
base:   4c87cdd0328495759f6e9f9f4e1e53ef8032a76f
patch link:    https://lore.kernel.org/r/20260205-dt-bindings-hwmon-pmbus-mpq8785-add-mpq8786-support-v2-3-3744cd9b2850%40amd.com
patch subject: [PATCH v2 3/3] hwmon: pmbus: mpq8785: force direct mode for VID VOUT on MPQ8785/MPQ8786
config: i386-randconfig-141-20260207 (https://download.01.org/0day-ci/archive/20260207/202602071928.rf2Gjdgd-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
smatch version: v0.5.0-8994-gd50c5a4c
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260207/202602071928.rf2Gjdgd-lkp@intel.com/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@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202602071928.rf2Gjdgd-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/hwmon/pmbus/mpq8785.c:63:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
      63 |         default:
         |         ^
   drivers/hwmon/pmbus/mpq8785.c:63:2: note: insert '__attribute__((fallthrough));' to silence this warning
      63 |         default:
         |         ^
         |         __attribute__((fallthrough)); 
   drivers/hwmon/pmbus/mpq8785.c:63:2: note: insert 'break;' to avoid fall-through
      63 |         default:
         |         ^
         |         break; 
   1 warning generated.


vim +63 drivers/hwmon/pmbus/mpq8785.c

    50	
    51	static int mpq8785_read_byte_data(struct i2c_client *client, int page, int reg)
    52	{
    53		int ret;
    54	
    55		switch (reg) {
    56		case PMBUS_VOUT_MODE:
    57			ret = pmbus_read_byte_data(client, page, reg);
    58			if (ret < 0)
    59				return ret;
    60	
    61			if ((ret >> 5) == 1)
    62				return PB_VOUT_MODE_DIRECT;
  > 63		default:
    64			return -ENODATA;
    65		}
    66	
    67		return ret;
    68	}
    69	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki