reproduce:
        git remote add drm-msm https://gitlab.freedesktop.org/drm/msm.git
        git fetch --no-tags drm-msm msm-fixes-external-fixes
        git checkout 471920ce25d50bb39bfdaf3c3d9bc9dde30fa265
        make menuconfig
        # enable CONFIG_COMPILE_TEST, CONFIG_WARN_MISSING_DOCUMENTS, CONFIG_WARN_ABI_ERRORS
        # pip install -r Documentation/sphinx/requirements.txt
        make htmldocs