reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        git checkout b601e1f41edd4667062aa7cccb4e5199814979a3
        b4 shazam https://lore.kernel.org/r/91ae8cd4f903ac452e337e4662bbabf8a412b061.1757318368.git.zhoubinbin@loongson.cn
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-15.1.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/tty/serial/8250/