reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-66-g0196afe1
        # https://github.com/steev/linux/commit/5835d87162afa8424c692a73a10ef5723dcc183b
        git remote add steev https://github.com/steev/linux
        git fetch --no-tags steev linux-5.10-gen-rkr3.4
        git checkout 5835d87162afa8424c692a73a10ef5723dcc183b
        # 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/base/ drivers/gpu/drm/ mm/