reproduce:
        git checkout defaf1a2113a22b00dfa1abc0fd2014820eaf065
        b4 shazam https://lore.kernel.org/r/20240831-en7581-pinctrl-v3-4-98eebfb4da66@kernel.org
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs