reproduce (this is a W=1 build):
        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-linux-gnu
        git remote add drm-xe https://gitlab.freedesktop.org/drm/xe/kernel.git
        git fetch drm-xe drm-xe-next
        git checkout drm-xe/drm-xe-next
        b4 shazam https://lore.kernel.org/r/20241113183550.6228-3-thomas.hellstrom@linux.intel.com
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-20 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/gpu/drm/ttm/