reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git/commit/?id=ef688d5100e8f263ae94a2c86260e7231d600c84
        git remote add rafael-pm https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git
        git fetch --no-tags rafael-pm bleeding-edge
        git checkout ef688d5100e8f263ae94a2c86260e7231d600c84
        # install riscv cross compiling tool for clang build
        # apt-get install binutils-riscv64-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=$HOME/0day COMPILER=clang-16 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-16 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=riscv SHELL=/bin/bash drivers/