Hi, I love your patch! Perhaps something to improve: [auto build test WARNING on helgaas-pci/next] [also build test WARNING 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-Finish-transition-to-L1-state-in-rcar_pcie_config_access/20220116-102631 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/20220117/202201170230.U9LeY58M-lkp@xxxxxxxxx/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project c63a3175c2947e8c1a2d3bbe16a8586600705c54) 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 # install arm cross compiling tool for clang build # apt-get install binutils-arm-linux-gnueabi # https://github.com/0day-ci/linux/commit/f784bebf4a058d633fc77579892309b12dd33edb 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=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/pci/controller/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> drivers/pci/controller/pcie-rcar-host.c:109:6: warning: no previous prototype for function 'rcar_pci_write_reg_workaround' [-Wmissing-prototypes] void rcar_pci_write_reg_workaround(struct rcar_pcie *pcie, u32 val, unsigned int reg) ^ drivers/pci/controller/pcie-rcar-host.c:109:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void rcar_pci_write_reg_workaround(struct rcar_pcie *pcie, u32 val, unsigned int reg) ^ static >> drivers/pci/controller/pcie-rcar-host.c:121:5: warning: no previous prototype for function 'rcar_pci_read_reg_workaround' [-Wmissing-prototypes] u32 rcar_pci_read_reg_workaround(struct rcar_pcie *pcie, unsigned int reg) ^ drivers/pci/controller/pcie-rcar-host.c:121:1: note: declare 'static' if the function is not intended to be used outside of this translation unit u32 rcar_pci_read_reg_workaround(struct rcar_pcie *pcie, unsigned int reg) ^ static drivers/pci/controller/pcie-rcar-host.c:114:4: error: instruction requires: data-barriers " isb\n" ^ <inline asm>:2:2: note: instantiated into assembly here isb ^ drivers/pci/controller/pcie-rcar-host.c:129:4: error: instruction requires: data-barriers " isb\n" ^ <inline asm>:3:2: note: instantiated into assembly here isb ^ drivers/pci/controller/pcie-rcar-host.c:114:4: error: instruction requires: data-barriers " isb\n" ^ <inline asm>:2:2: note: instantiated into assembly here isb ^ drivers/pci/controller/pcie-rcar-host.c:127:3: error: symbol 'rcar_pci_read_reg_workaround_start' is already defined "rcar_pci_read_reg_workaround_start:\n" ^ <inline asm>:1:2: note: instantiated into assembly here rcar_pci_read_reg_workaround_start: ^ drivers/pci/controller/pcie-rcar-host.c:129:4: error: instruction requires: data-barriers " isb\n" ^ <inline asm>:3:2: note: instantiated into assembly here isb ^ 2 warnings and 5 errors generated. vim +/rcar_pci_write_reg_workaround +109 drivers/pci/controller/pcie-rcar-host.c 108 > 109 void rcar_pci_write_reg_workaround(struct rcar_pcie *pcie, u32 val, unsigned int reg) 110 { 111 #ifdef CONFIG_ARM 112 asm volatile( 113 " str %0, [%1]\n" 114 " isb\n" 115 ::"r"(val), "r"(pcie->base + reg):"memory"); 116 #else 117 rcar_pci_write_reg(pcie, val, reg); 118 #endif 119 } 120 > 121 u32 rcar_pci_read_reg_workaround(struct rcar_pcie *pcie, unsigned int reg) 122 { 123 #ifdef CONFIG_ARM 124 u32 val; 125 126 asm volatile( 127 "rcar_pci_read_reg_workaround_start:\n" 128 "1: ldr %0, [%1]\n" 129 " isb\n" 130 : "=r"(val):"r"(pcie->base + reg):"memory"); 131 132 return val; 133 #else 134 return rcar_pci_read_reg(pcie, reg); 135 #endif 136 } 137 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx