reproduce (this is a W=1 build):
        git remote add agd5f https://gitlab.freedesktop.org/agd5f/linux.git
        git fetch --no-tags agd5f drm-next
        git checkout ff780f4f80323148d43198f2052c14160c8428d3
        # install s390 cross compiling tool for clang build
        # apt-get install binutils-s390x-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=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang-19 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=s390 SHELL=/bin/bash drivers/gpu/drm/amd/amdgpu/