reproduce:
        git remote add linuxtv-media-pending https://git.linuxtv.org/media-ci/media-pending.git
        git fetch --no-tags linuxtv-media-pending next
        git checkout 447ea0c26e57c1b423426e6c46d7ff89fd66eb6b
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs