Hi Pavo,

I love your patch! Perhaps something to improve:

[auto build test WARNING on hwmon/hwmon-next]
[also build test WARNING on pavel-linux-leds/for-next lee-mfd/for-mfd-next v5.13 next-20210701]
[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/Pavo-Banicevic/Add-support-for-the-IEI-WT61P803-PUZZLE-MCU/20210705-215150
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
config: arc-allyesconfig (attached as .config)
compiler: arceb-elf-gcc (GCC) 9.3.0
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
        # https://github.com/0day-ci/linux/commit/fd7335dc2a71b541d72f88ca1f251e201790f718
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Pavo-Banicevic/Add-support-for-the-IEI-WT61P803-PUZZLE-MCU/20210705-215150
        git checkout fd7335dc2a71b541d72f88ca1f251e201790f718
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arc 

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/mfd/iei-wt61p803-puzzle.c:277:5: warning: no previous prototype for 'iei_wt61p803_puzzle_buzzer' [-Wmissing-prototypes]
     277 | int iei_wt61p803_puzzle_buzzer(struct iei_wt61p803_puzzle *mcu, bool long_beep)
         |     ^~~~~~~~~~~~~~~~~~~~~~~~~~


vim +/iei_wt61p803_puzzle_buzzer +277 drivers/mfd/iei-wt61p803-puzzle.c

   276	
 > 277	int iei_wt61p803_puzzle_buzzer(struct iei_wt61p803_puzzle *mcu, bool long_beep)
   278	{
   279		unsigned char *resp_buf = mcu->response_buffer;
   280		unsigned char buzzer_cmd[4] = {};
   281		size_t reply_size;
   282		int ret;
   283	
   284		buzzer_cmd[0] = IEI_WT61P803_PUZZLE_CMD_HEADER_START;
   285		buzzer_cmd[1] = IEI_WT61P803_PUZZLE_CMD_FUNCTION_SINGLE;
   286		buzzer_cmd[2] = long_beep ? '3' : '2'; /* Buzzer 1.5 / 0.5 second beep */
   287	
   288		mutex_lock(&mcu->lock);
   289		ret = iei_wt61p803_puzzle_write_command(mcu, buzzer_cmd, sizeof(buzzer_cmd),
   290							resp_buf, &reply_size);
   291		if (ret)
   292			goto exit;
   293	
   294		if (reply_size != 3) {
   295			ret = -EIO;
   296			goto exit;
   297		}
   298	
   299		if (!(resp_buf[0] == IEI_WT61P803_PUZZLE_CMD_HEADER_START &&
   300		      resp_buf[1] == IEI_WT61P803_PUZZLE_CMD_RESPONSE_OK &&
   301		      resp_buf[2] == IEI_WT61P803_PUZZLE_CHECKSUM_RESPONSE_OK)) {
   302			ret = -EPROTO;
   303			goto exit;
   304		}
   305	exit:
   306		mutex_unlock(&mcu->lock);
   307		return ret;
   308	}
   309	

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