Hi Xiaoliang,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on net-next/master]

url:    https://github.com/0day-ci/linux/commits/Xiaoliang-Yang/net-stmmac-re-configure-tas-basetime-after-ptp-time-adjust/20210601-163025
base:   https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 7fc6d3abc0844a9b8ef67937af465a417af6e9e9
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/5abe8df9d55824e7eff47e48b66f57260b0bfe50
        git remote add linux-review https://github.com/0day-ci/linux
        git fetch --no-tags linux-review Xiaoliang-Yang/net-stmmac-re-configure-tas-basetime-after-ptp-time-adjust/20210601-163025
        git checkout 5abe8df9d55824e7eff47e48b66f57260b0bfe50
        # 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/net/ethernet/stmicro/stmmac/stmmac_tc.c:716:19: warning: no previous prototype for 'stmmac_calc_tas_basetime' [-Wmissing-prototypes]
     716 | struct timespec64 stmmac_calc_tas_basetime(ktime_t old_base_time,
         |                   ^~~~~~~~~~~~~~~~~~~~~~~~


vim +/stmmac_calc_tas_basetime +716 drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c

   715	
 > 716	struct timespec64 stmmac_calc_tas_basetime(ktime_t old_base_time,
   717						   ktime_t current_time,
   718						   u64 cycle_time)
   719	{
   720		struct timespec64 time;
   721	
   722		if (ktime_after(old_base_time, current_time)) {
   723			time = ktime_to_timespec64(old_base_time);
   724		} else {
   725			s64 n;
   726			ktime_t base_time;
   727	
   728			n = div64_s64(ktime_sub_ns(current_time, old_base_time),
   729				      cycle_time);
   730			base_time = ktime_add_ns(old_base_time,
   731						 (n + 1) * cycle_time);
   732	
   733			time = ktime_to_timespec64(base_time);
   734		}
   735	
   736		return time;
   737	}
   738	

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