tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: ec2618180c3450d06a6a4ba951d4c9a2c689b517 commit: cac6fb015f719104e60b1c68c15ca5b734f57b9c [2317/2770] usb: class: cdc-wdm: WWAN framework integration config: parisc-randconfig-r033-20210513 (attached as .config) compiler: hppa-linux-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/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout cac6fb015f719104e60b1c68c15ca5b734f57b9c # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross W=1 ARCH=parisc 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 >>): hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_stop': hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_tx': (.text+0xf88): undefined reference to `wwan_port_get_drvdata' hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_start': (.text+0x1064): undefined reference to `wwan_port_get_drvdata' hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_wwan_port_tx_complete': hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_in_callback': (.text+0x13cc): undefined reference to `wwan_port_rx' hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_disconnect': hppa-linux-ld: drivers/usb/class/cdc-wdm.o: in function `wdm_create': --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org