reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/rw/misc.git/commit/?id=0faa34f64f7a0f3792e34721e8c807652946f054
        git remote add rw-misc https://git.kernel.org/pub/scm/linux/kernel/git/rw/misc.git
        git fetch --no-tags rw-misc omap_debugfs_v1
        git checkout 0faa34f64f7a0f3792e34721e8c807652946f054

        # 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/base/regmap/