reproduce:
        git checkout 8c6bc74c7f8910ed4c969ccec52e98716f98700a
        b4 shazam https://lore.kernel.org/r/20250614-axiado-ax3000-soc-and-evaluation-board-support-v1-6-327ab344c16d@axiado.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 3.4.3
        make htmldocs