reproduce (this is a W=1 build):
        git checkout 11439c4635edd669ae435eec308f4ab8a0804808
        b4 shazam https://lore.kernel.org/r/20260305-fix_sierra_get_parent-v1-1-a7c18e9e6c58@bootlin.com

        git clone https://github.com/intel/lkp-tests.git ~/lkp-tests

        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=xtensa olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-8.5.0 ~/lkp-tests/kbuild/make.cross W=1 O=build_dir ARCH=xtensa SHELL=/bin/bash drivers/phy/cadence/