reproduce (this is a W=1 build):
        # https://git.kernel.org/pub/scm/linux/kernel/git/mwalle/linux.git/commit/?id=e4ce6aa7f23f3b9ed2d3778ff9799f67757246d1
        git remote add mwalle https://git.kernel.org/pub/scm/linux/kernel/git/mwalle/linux.git
        git fetch --no-tags mwalle for-next
        git checkout e4ce6aa7f23f3b9ed2d3778ff9799f67757246d1

        # 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/mtd/spi-nor/