Hi Guanbing, kernel test robot noticed the following build errors: [auto build test ERROR on tty/tty-testing] [also build test ERROR on tty/tty-next tty/tty-linus usb/usb-testing usb/usb-next usb/usb-linus linus/master v6.9-rc3 next-20240409] [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/Guanbing-Huang/PNP-Add-dev_is_pnp-macro/20240409-154558 base: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing patch link: https://lore.kernel.org/r/e6dc33e399f119e6430bca48223cb2127930939b.1712646750.git.albanhuang%40tencent.com patch subject: [PATCH v6 2/3] serial: port: Add support of PNP IRQ to __uart_read_properties() config: sparc-allnoconfig (https://download.01.org/0day-ci/archive/20240410/202404100548.rbAa11Xr-lkp@xxxxxxxxx/config) compiler: sparc-linux-gcc (GCC) 13.2.0 reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240410/202404100548.rbAa11Xr-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202404100548.rbAa11Xr-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): sparc-linux-ld: drivers/tty/serial/serial_port.o: in function `__uart_read_properties': serial_port.c:(.text+0x1c4): undefined reference to `pnp_bus_type' >> sparc-linux-ld: serial_port.c:(.text+0x1c8): undefined reference to `pnp_bus_type' -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki