Hi Christophe, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master head: fa54d366a6e4fe3e16322abdb8b5115f8be0da8b commit: 7d68c89169508064c460a1208f38ed0589d226fa powerpc/32s: Allow deselecting CONFIG_PPC_FPU on mpc832x date: 9 months ago config: powerpc64-buildonly-randconfig-r004-20210820 (attached as .config) compiler: powerpc-linux-gcc (GCC) 11.2.0 reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7d68c89169508064c460a1208f38ed0589d226fa git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git git fetch --no-tags linus master git checkout 7d68c89169508064c460a1208f38ed0589d226fa # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All errors (new ones prefixed by >>): arch/powerpc/platforms/52xx/lite5200_pm.c: In function 'lite5200_pm_enter': >> arch/powerpc/platforms/52xx/lite5200_pm.c:215:9: error: implicit declaration of function 'enable_kernel_fp' [-Werror=implicit-function-declaration] 215 | enable_kernel_fp(); | ^~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors -- arch/powerpc/platforms/83xx/suspend.c: In function 'mpc83xx_suspend_enter': >> arch/powerpc/platforms/83xx/suspend.c:210:17: error: implicit declaration of function 'enable_kernel_fp' [-Werror=implicit-function-declaration] 210 | enable_kernel_fp(); | ^~~~~~~~~~~~~~~~ cc1: all warnings being treated as errors vim +/enable_kernel_fp +215 arch/powerpc/platforms/52xx/lite5200_pm.c ee983079ce0464 Domen Puncer 2007-07-18 204 ee983079ce0464 Domen Puncer 2007-07-18 205 static int lite5200_pm_enter(suspend_state_t state) ee983079ce0464 Domen Puncer 2007-07-18 206 { ee983079ce0464 Domen Puncer 2007-07-18 207 /* deep sleep? let mpc52xx code handle that */ ee983079ce0464 Domen Puncer 2007-07-18 208 if (state == PM_SUSPEND_STANDBY) { ee983079ce0464 Domen Puncer 2007-07-18 209 return mpc52xx_pm_enter(state); ee983079ce0464 Domen Puncer 2007-07-18 210 } ee983079ce0464 Domen Puncer 2007-07-18 211 ee983079ce0464 Domen Puncer 2007-07-18 212 lite5200_save_regs(); ee983079ce0464 Domen Puncer 2007-07-18 213 ee983079ce0464 Domen Puncer 2007-07-18 214 /* effectively save FP regs */ ee983079ce0464 Domen Puncer 2007-07-18 @215 enable_kernel_fp(); ee983079ce0464 Domen Puncer 2007-07-18 216 ee983079ce0464 Domen Puncer 2007-07-18 217 lite5200_low_power(sram, mbar); ee983079ce0464 Domen Puncer 2007-07-18 218 ee983079ce0464 Domen Puncer 2007-07-18 219 lite5200_restore_regs(); ee983079ce0464 Domen Puncer 2007-07-18 220 ee983079ce0464 Domen Puncer 2007-07-18 221 iounmap(mbar); ee983079ce0464 Domen Puncer 2007-07-18 222 return 0; ee983079ce0464 Domen Puncer 2007-07-18 223 } ee983079ce0464 Domen Puncer 2007-07-18 224 :::::: The code at line 215 was first introduced by commit :::::: ee983079ce04641523b23b8ed02cc3503632351e [POWERPC] MPC5200 low power mode :::::: TO: Domen Puncer :::::: CC: Paul Mackerras --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org