Hi Linus, I love your patch! Perhaps something to improve: [auto build test WARNING on pci/next] [also build test WARNING on soc/for-next linus/master v5.13-rc5 next-20210608] [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/Linus-Walleij/PCI-ixp4xx-Add-a-n... base: https://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci.git next config: arm-ixp4xx_defconfig (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 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/83fea9cccbfbf3100a065cdc485d71e62... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Linus-Walleij/PCI-ixp4xx-Add-a-new-driver-for-IXP4xx/20210607-211258 git checkout 83fea9cccbfbf3100a065cdc485d71e623d3f54a # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All warnings (new ones prefixed by >>): 38 | #define IXP4XX_PCI_CSR 0x1c | In file included from arch/arm/mach-ixp4xx/include/mach/hardware.h:23, from arch/arm/mach-ixp4xx/include/mach/io.h:15, from arch/arm/include/asm/io.h:198, from include/linux/io.h:13, from drivers/pci/controller/pci-ixp4xx.c:20: arch/arm/mach-ixp4xx/include/mach/ixp4xx-regs.h:220: note: this is the location of the previous definition 220 | #define IXP4XX_PCI_CSR(x) ((volatile u32 *)(IXP4XX_PCI_CFG_BASE_VIRT+(x))) | drivers/pci/controller/pci-ixp4xx.c:148:12: error: 'ixp4xx_pci_read' redeclared as different kind of symbol 148 | static int ixp4xx_pci_read(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 *data) | ^~~~~~~~~~~~~~~ In file included from arch/arm/include/asm/io.h:198, from include/linux/io.h:13, from drivers/pci/controller/pci-ixp4xx.c:20: arch/arm/mach-ixp4xx/include/mach/io.h:17:14: note: previous declaration of 'ixp4xx_pci_read' was here 17 | extern int (*ixp4xx_pci_read)(u32 addr, u32 cmd, u32* data); | ^~~~~~~~~~~~~~~ drivers/pci/controller/pci-ixp4xx.c:178:12: error: conflicting types for 'ixp4xx_pci_write' 178 | static int ixp4xx_pci_write(struct ixp4xx_pci *p, u32 addr, u32 cmd, u32 data) | ^~~~~~~~~~~~~~~~ In file included from arch/arm/include/asm/io.h:198, from include/linux/io.h:13, from drivers/pci/controller/pci-ixp4xx.c:20: arch/arm/mach-ixp4xx/include/mach/io.h:18:12: note: previous declaration of 'ixp4xx_pci_write' was here 18 | extern int ixp4xx_pci_write(u32 addr, u32 cmd, u32 data); | ^~~~~~~~~~~~~~~~ vim +/IXP4XX_PCI_CSR +38 drivers/pci/controller/pci-ixp4xx.c 29 30 /* Register offsets */ 31 #define IXP4XX_PCI_NP_AD 0x00 32 #define IXP4XX_PCI_NP_CBE 0x04 33 #define IXP4XX_PCI_NP_WDATA 0x08 34 #define IXP4XX_PCI_NP_RDATA 0x0c 35 #define IXP4XX_PCI_CRP_AD_CBE 0x10 36 #define IXP4XX_PCI_CRP_WDATA 0x14 37 #define IXP4XX_PCI_CRP_RDATA 0x18 39 #define IXP4XX_PCI_ISR 0x20 40 #define IXP4XX_PCI_INTEN 0x24 41 #define IXP4XX_PCI_DMACTRL 0x28 42 #define IXP4XX_PCI_AHBMEMBASE 0x2c 43 #define IXP4XX_PCI_AHBIOBASE 0x30 44 #define IXP4XX_PCI_PCIMEMBASE 0x34 45 #define IXP4XX_PCI_AHBDOORBELL 0x38 46 #define IXP4XX_PCI_PCIDOORBELL 0x3C 47 #define IXP4XX_PCI_ATPDMA0_AHBADDR 0x40 48 #define IXP4XX_PCI_ATPDMA0_PCIADDR 0x44 49 #define IXP4XX_PCI_ATPDMA0_LENADDR 0x48 50 #define IXP4XX_PCI_ATPDMA1_AHBADDR 0x4C 51 #define IXP4XX_PCI_ATPDMA1_PCIADDR 0x50 52 #define IXP4XX_PCI_ATPDMA1_LENADDR 0x54 53 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org