reproduce:
        # apt-get install sparse
        # sparse version: v0.6.4-66-g0196afe1
        # https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux.git/commit/?id=485dd5c359970c7a431596bcd8c4469362915eba
        git remote add cel https://git.kernel.org/pub/scm/linux/kernel/git/cel/linux
        git fetch --no-tags cel nfsd-5.10.y
        git checkout 485dd5c359970c7a431596bcd8c4469362915eba
        # 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/i2c/