reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git/commit/?id=2acbb5e57230830016e0fb2d61886e7a8c7f59ce
        git remote add tiwai-sound https://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound.git
        git fetch --no-tags tiwai-sound for-next
        git checkout 2acbb5e57230830016e0fb2d61886e7a8c7f59ce
        # 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 sound/pcmcia/vx/