Hi Krzysztof,

I love your patch! Perhaps something to improve:

[auto build test WARNING on hwmon/hwmon-next]
[also build test WARNING on robh/for-next v5.14 next-20210907]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch]

url:    https://github.com/0day-ci/linux/commits/Krzysztof-Adamski/Add-per-channel-properies-support-in-tmp421/20210907-214724
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
config: mips-randconfig-c004-20210907 (attached as .config)
compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 9c476172b93367d2cb88d7d3f4b1b5b456fa6020)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips-linux-gnu
        # https://github.com/0day-ci/linux/commit/56fe3c49ca67e9ea9c4f8a40438b5adc58c417f1
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Krzysztof-Adamski/Add-per-channel-properies-support-in-tmp421/20210907-214724
        git checkout 56fe3c49ca67e9ea9c4f8a40438b5adc58c417f1
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=mips 

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>

All warnings (new ones prefixed by >>):

   drivers/hwmon/tmp421.c:301:6: warning: no previous prototype for function 'tmp421_probe_child_from_dt' [-Wmissing-prototypes]
   void tmp421_probe_child_from_dt(struct i2c_client *client,
        ^
   drivers/hwmon/tmp421.c:301:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void tmp421_probe_child_from_dt(struct i2c_client *client,
   ^
   static 
   drivers/hwmon/tmp421.c:345:6: warning: no previous prototype for function 'tmp421_probe_from_dt' [-Wmissing-prototypes]
   void tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)
        ^
   drivers/hwmon/tmp421.c:345:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void tmp421_probe_from_dt(struct i2c_client *client, struct tmp421_data *data)
   ^
   static 
>> drivers/hwmon/tmp421.c:356:6: warning: no previous prototype for function 'tmp421_disable_channels' [-Wmissing-prototypes]
   void tmp421_disable_channels(struct i2c_client *client, uint8_t mask)
        ^
   drivers/hwmon/tmp421.c:356:1: note: declare 'static' if the function is not intended to be used outside of this translation unit
   void tmp421_disable_channels(struct i2c_client *client, uint8_t mask)
   ^
   static 
   3 warnings generated.


vim +/tmp421_disable_channels +356 drivers/hwmon/tmp421.c

   355	
 > 356	void tmp421_disable_channels(struct i2c_client *client, uint8_t mask)
   357	{
   358		int err;
   359		int cfg = i2c_smbus_read_byte_data(client, TMP421_CONFIG_REG_2);
   360	
   361		if (cfg < 0) {
   362			dev_err(&client->dev,
   363				"error reading register, can't disable channels\n");
   364			return;
   365		}
   366	
   367		cfg &= ~mask;
   368	
   369		err = i2c_smbus_write_byte_data(client, TMP421_CONFIG_REG_2, cfg);
   370		if (err < 0)
   371			dev_err(&client->dev,
   372				"error writing register, can't disable channels\n");
   373	}
   374	

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org