reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-52-g1cf3d98c-dirty
        # https://github.com/jimc/linux/commit/4e29874e95dbb4062f7e9528992bcfdb0100dfae
        git remote add jimc https://github.com/jimc/linux.git
        git fetch --no-tags jimc lukas-v4a
        git checkout 4e29874e95dbb4062f7e9528992bcfdb0100dfae
        # 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=x86_64 olddefconfig
        make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__ -fmax-errors=unlimited -fmax-warnings=unlimited' O=build_dir ARCH=x86_64 SHELL=/bin/bash drivers/net/