Hi Macpaul,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on linus/master]
[also build test WARNING on v5.14-rc3 next-20210726]
[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/Macpaul-Lin/phy-introduce-phy-mode-PHY_MODE_UART-and-phy_get_mode_ext/20210727-185332
base:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git ff1176468d368232b684f75e82563369208bc371
config: mips-randconfig-s031-20210727 (attached as .config)
compiler: mips-linux-gcc (GCC) 10.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.3-341-g8af24329-dirty
        # https://github.com/0day-ci/linux/commit/fa58db3bf0689ed034e7871c053bfd65592b486e
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Macpaul-Lin/phy-introduce-phy-mode-PHY_MODE_UART-and-phy_get_mode_ext/20210727-185332
        git checkout fa58db3bf0689ed034e7871c053bfd65592b486e
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-10.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' 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/phy/phy-core.c:376:5: warning: no previous prototype for 'phy_get_mode_ext' [-Wmissing-prototypes]
     376 | int phy_get_mode_ext(struct phy *phy)
         |     ^~~~~~~~~~~~~~~~


vim +/phy_get_mode_ext +376 drivers/phy/phy-core.c

   375	
 > 376	int phy_get_mode_ext(struct phy *phy)
   377	{
   378		int ret;
   379	
   380		if (!phy || !phy->ops->get_mode_ext)
   381			return 0;
   382	
   383		mutex_lock(&phy->mutex);
   384		ret = phy->ops->get_mode_ext(phy);
   385		if (!ret)
   386			ret = phy->attrs.mode;
   387		mutex_unlock(&phy->mutex);
   388	
   389		return ret;
   390	}
   391	EXPORT_SYMBOL_GPL(phy_get_mode_ext);
   392	

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