reproduce:
        git checkout 07d4d0bb4a8ddcc463ed599b22f510d5926c2495
        b4 shazam https://lore.kernel.org/r/20240627-eblanc-ad4630_v1-v1-1-fdc0610c23b0@baylibre.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs