reproduce (this is a W=1 build):
        git remote add drm-misc git://anongit.freedesktop.org/drm/drm-misc
        git fetch --no-tags drm-misc drm-misc-next
        git checkout 3a9b77cee7502f7450c725d4ead2c4a44924d158
        # 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/