reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install mips cross compiling tool for clang build
        # apt-get install binutils-mips64el-linux-gnuabi64
        # clang-21 might not be officially released. Try a lower version if installation fails.
        # https://github.com/isilence/linux/commit/472d8fb34f0651bf981165606769a5c73f41ce7f
        git remote add isilence https://github.com/isilence/linux
        git fetch --no-tags isilence zcrx-dmabuf
        git checkout 472d8fb34f0651bf981165606769a5c73f41ce7f
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-21 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=mips olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-21 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=mips SHELL=/bin/bash