reproduce:
        mkdir -p ~/bin
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # apt-get install sparse
        # sparse version: v0.6.4-39-gce1a6720-dirty
        # https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/chromeos.git/commit/?id=488c5dc8526b11ef7e565e4094620876ebb470f8
        git remote add iwlwifi-chromeos https://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/chromeos.git
        git fetch --no-tags iwlwifi-chromeos chromeos-5.10__release/core61-58
        git checkout 488c5dc8526b11ef7e565e4094620876ebb470f8
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=sparc64 olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.3.0 ~/bin/make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' O=build_dir ARCH=sparc64 SHELL=/bin/bash drivers/gpu/drm/ttm/