[kbuild-all] [chunkuang.hu:mediatek-cmdq3 18/21] ERROR: modpost: "mtk_mutex_prepare" undefined!

tree: https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git mediatek-cmdq3 head: f437ef81a7d0ae27bc340382cdfe96228307d5bf commit: 975dacd7c4d260adda0348a9f0227e50c16390a0 [18/21] soc / drm: mediatek: Move mtk mutex driver to soc folder config: arm-allmodconfig (attached as .config) compiler: arm-linux-gnueabi-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://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git/co... git remote add chunkuang.hu https://git.kernel.org/pub/scm/linux/kernel/git/chunkuang.hu/linux.git git fetch --no-tags chunkuang.hu mediatek-cmdq3 git checkout 975dacd7c4d260adda0348a9f0227e50c16390a0 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>, old ones prefixed by <<): --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org