Hi Xu, Thank you for the patch! Yet something to improve: [auto build test ERROR on usb/usb-testing] [also build test ERROR on shawnguo/for-next linus/master v6.0-rc2 next-20220822] [cannot apply to robh/for-next] [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#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Xu-Yang/typec-orientation-switch-support-via-mux-controller/20220822-153600 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing config: i386-randconfig-a013-20220822 (https://download.01.org/0day-ci/archive/20220822/202208222312.IFf74Ze6-lkp@xxxxxxxxx/config) compiler: gcc-11 (Debian 11.3.0-5) 11.3.0 reproduce (this is a W=1 build): # https://github.com/intel-lab-lkp/linux/commit/703ba3cfec5b6f9422ac9a859bc6121f7c4a12fd git remote add linux-review https://github.com/intel-lab-lkp/linux git fetch --no-tags linux-review Xu-Yang/typec-orientation-switch-support-via-mux-controller/20220822-153600 git checkout 703ba3cfec5b6f9422ac9a859bc6121f7c4a12fd # save the config file mkdir build_dir && cp config build_dir/.config make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable Reported-by: kernel test robot <lkp@xxxxxxxxx> All errors (new ones prefixed by >>): ld: drivers/usb/typec/mux.o: in function `typec_switch_put': >> mux.c:(.text+0x21d): undefined reference to `mux_control_put' ld: drivers/usb/typec/mux.o: in function `typec_switch_set': >> mux.c:(.text+0x29a): undefined reference to `mux_control_deselect' >> ld: mux.c:(.text+0x2ab): undefined reference to `mux_control_select_delay' ld: drivers/usb/typec/mux.o: in function `typec_switch_get': >> mux.c:(.text+0x767): undefined reference to `mux_control_get' -- 0-DAY CI Kernel Test Service https://01.org/lkp