reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/wens/linux.git/commit/?id=f1ca288bbc7fd436be87f32f0c7863489d92b982
        git remote add wens https://git.kernel.org/pub/scm/linux/kernel/git/wens/linux.git
        git fetch --no-tags wens mtk-wip
        git checkout f1ca288bbc7fd436be87f32f0c7863489d92b982
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        make W=1 O=build_dir ARCH=i386 olddefconfig
        make W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/gpu/drm/