reproduce (this is a W=1 build):
        git remote add drm-misc https://gitlab.freedesktop.org/drm/misc/kernel.git
        git fetch drm-misc drm-misc-next
        git checkout drm-misc/drm-misc-next
        b4 shazam https://lore.kernel.org/r/20251212.210504.1355099120650239629.rene@exactco.de

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests
        # apt-get install sparse
        # sparse version: v0.6.4-73-gfbdde312

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=openrisc olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.5.0 ~/lkp-tests/kbuild/make.cross W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=openrisc SHELL=/bin/bash drivers/gpu/drm/ast/