reproduce:
        git checkout 232f121837ad8b1c21cc80f2c8842a4090c5a2a0
        b4 shazam https://lore.kernel.org/r/20250123-dma-v1-1-054f1a77e733@microchip.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs