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 a6332b84718710f22b7392d5773675c5942faa7d
        # apt-get install sparse
        # sparse: v0.6.5-rc1

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/amd/amdgpu/