Hi Yu, Thank you for the patch! Yet something to improve: [auto build test ERROR on tty/tty-testing] [also build test ERROR on next-20220112] [cannot apply to robh/for-next soc/for-next clk/clk-next v5.16] [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/Yu-Tu/the-UART-driver-compatible... base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing config: powerpc-randconfig-s031-20220112 (https://download.01.org/0day-ci/archive/20220113/202201130331.dzluDr3h-lk...) compiler: powerpc-linux-gcc (GCC) 11.2.0 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: v0.6.4-dirty # https://github.com/0day-ci/linux/commit/6d55159e6626326d9001d4c8f20b914a6... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Yu-Tu/the-UART-driver-compatible-with/20220110-170020 git checkout 6d55159e6626326d9001d4c8f20b914a69c2c40b # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=powerpc SHELL=/bin/bash 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 >>): powerpc-linux-ld: drivers/tty/serial/meson_uart.o: in function `meson_uart_probe_clocks': meson_uart.c:(.text+0x464): undefined reference to `__clk_get_name' powerpc-linux-ld: meson_uart.c:(.text+0x640): undefined reference to `__devm_clk_hw_register_divider' --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org