reproduce:
        git checkout 0af2f6be1b4281385b618cb86ad946eded089ac8
        b4 shazam https://lore.kernel.org/r/20250430-vt8500-i2c-binding-v2-1-0cf22d0c2d42@gmail.com
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # install Sphinx 2.4.4
        make htmldocs