Hi Sean, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on pci/next] [also build test WARNING on v5.7-rc6 next-20200518] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Sean-V-Kelley/PCI-Add-basic-Comp... base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next config: powerpc-defconfig (attached as .config) compiler: powerpc64-linux-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=powerpc If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>, old ones prefixed by <<): In file included from drivers/pci/hotplug/pci_hotplug_core.c:32: drivers/pci/hotplug/../pci.h: In function 'pci_cxl_mem_enable': 481 | static inline int pci_cxl_mem_enable(struct pci_dev *dev) {} | ^~~~~~~ drivers/pci/hotplug/../pci.h: In function 'pci_cxl_cache_enable': drivers/pci/hotplug/../pci.h:483:47: warning: no return statement in function returning non-void [-Wreturn-type] 483 | static inline int pci_cxl_cache_enable(struct pci_dev *dev) {} | ^~~~~~~ vim +481 drivers/pci/hotplug/../pci.h 471 472 #ifdef CONFIG_PCI_CXL 473 /* Compute eXpress Link */ 474 void pci_cxl_init(struct pci_dev *dev); 475 int pci_cxl_mem_enable(struct pci_dev *dev); 476 void pci_cxl_mem_disable(struct pci_dev *dev); 477 int pci_cxl_cache_enable(struct pci_dev *dev); 478 void pci_cxl_cache_disable(struct pci_dev *dev); 479 #else 480 static inline void pci_cxl_init(struct pci_dev *dev) { } 482 static inline void pci_cxl_mem_disable(struct pci_dev *dev) {} 483 static inline int pci_cxl_cache_enable(struct pci_dev *dev) {} 484 static inline void pci_cxl_cache_disable(struct pci_dev *dev) {} 485 #endif 486 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org