reproduce (this is a W=1 build):
        git checkout b9810cd75b9fb56a3425d391cba3f608502bd474
        b4 shazam https://lore.kernel.org/r/20260710-remove_uart_change_state-v1-1-8e8468da22a1@oss.qualcomm.com

        # install loongarch cross compiling tool for clang build
        # apt-get install binutils-loongarch-linux-gnu
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=loongarch olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-18 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=loongarch SHELL=/bin/bash drivers/tty/serial/