Hi, I love your patch! Yet something to improve: [auto build test ERROR on helgaas-pci/next] [also build test ERROR on next-20220116] [cannot apply to v5.16] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/marek-vasut-gmail-com/PCI-rcar-F... base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next config: arm-randconfig-c002-20220116 (https://download.01.org/0day-ci/archive/20220117/202201170402.sPT8Gtpa-lk...) compiler: arm-linux-gnueabi-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://github.com/0day-ci/linux/commit/f784bebf4a058d633fc77579892309b12... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review marek-vasut-gmail-com/PCI-rcar-Finish-transition-to-L1-state-in-rcar_pcie_config_access/20220116-102631 git checkout f784bebf4a058d633fc77579892309b12dd33edb # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.2.0 make.cross O=build_dir ARCH=arm SHELL=/bin/bash If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): drivers/pci/controller/pcie-rcar-host.c:109:6: warning: no previous prototype for 'rcar_pci_write_reg_workaround' [-Wmissing-prototypes] 109 | void rcar_pci_write_reg_workaround(struct rcar_pcie *pcie, u32 val, unsigned int reg) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~ drivers/pci/controller/pcie-rcar-host.c:121:5: warning: no previous prototype for 'rcar_pci_read_reg_workaround' [-Wmissing-prototypes] 121 | u32 rcar_pci_read_reg_workaround(struct rcar_pcie *pcie, unsigned int reg) | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /tmp/ccquRjDl.s: Assembler messages: /tmp/ccquRjDl.s:1425: Error: selected processor does not support `isb' in ARM mode /tmp/ccquRjDl.s:1486: Error: selected processor does not support `isb' in ARM mode /tmp/ccquRjDl.s:2594: Error: selected processor does not support `isb' in ARM mode /tmp/ccquRjDl.s:2624: Error: selected processor does not support `isb' in ARM mode --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org