reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git/commit/?id=a01061a0afbd18bce634e772e050c78ce6bd8fdc
        git remote add wsa https://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux.git
        git fetch --no-tags wsa renesas/sdhi/tmio-simplification
        git checkout a01061a0afbd18bce634e772e050c78ce6bd8fdc
        # 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/mmc/host/