Hi Uwe, FYI, the error/warning was bisected to this commit, please ignore it if it's irrelevant. tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git tty-testing head: 617ece73dd240cb11869a224c879ca685a151a38 commit: a0807ca158e00af2909f3d34a36c28b57b07ab06 [13/17] serial: 8250: Apply FSL workarounds also without SERIAL_8250_CONSOLE config: mips-allmodconfig (https://download.01.org/0day-ci/archive/20230531/202305310433.jhGB8PhI-lkp@xxxxxxxxx/config) compiler: mips-linux-gcc (GCC) 12.3.0 reproduce (this is a W=1 build): mkdir -p ~/bin 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/gregkh/tty.git/commit/?id=a0807ca158e00af2909f3d34a36c28b57b07ab06 git remote add tty https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git git fetch --no-tags tty tty-testing git checkout a0807ca158e00af2909f3d34a36c28b57b07ab06 # save the config file mkdir build_dir && cp config build_dir/.config COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=mips olddefconfig COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash If you fix the issue, kindly add following tag where applicable | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202305310433.jhGB8PhI-lkp@xxxxxxxxx/ All errors (new ones prefixed by >>): mips-linux-ld: drivers/tty/serial/8250/8250_fsl.o: in function `fsl8250_handle_irq': >> 8250_fsl.c:(.text.fsl8250_handle_irq+0x140): undefined reference to `serial8250_rx_chars' >> mips-linux-ld: 8250_fsl.c:(.text.fsl8250_handle_irq+0x220): undefined reference to `serial8250_modem_status' >> mips-linux-ld: 8250_fsl.c:(.text.fsl8250_handle_irq+0x268): undefined reference to `serial8250_tx_chars' -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
