Hi Florinel, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on net-next/master] url: https://github.com/0day-ci/linux/commits/Florinel-Iordache/doc-net-add-backplane-documentation/20200622-223623 base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 29a720c1042f469c8fea317cb5e7f496b116e07d config: mips-allyesconfig (attached as .config) compiler: mips-linux-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 # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot All warnings (new ones prefixed by >>, old ones prefixed by <<): >> drivers/net/phy/backplane/qoriq_backplane.c:150:18: warning: no previous prototype for 'get_serdes_type' [-Wmissing-prototypes] 150 | enum serdes_type get_serdes_type(struct device_node *serdes_node) | ^~~~~~~~~~~~~~~ vim +/get_serdes_type +150 drivers/net/phy/backplane/qoriq_backplane.c 149 > 150 enum serdes_type get_serdes_type(struct device_node *serdes_node) 151 { 152 enum serdes_type serdes = SERDES_INVAL; 153 const char *serdes_comp; 154 int comp_no, i, ret; 155 156 comp_no = of_property_count_strings(serdes_node, "compatible"); 157 for (i = 0; i < comp_no; i++) { 158 ret = of_property_read_string_index(serdes_node, "compatible", 159 i, &serdes_comp); 160 if (ret == 0) { 161 if (!strcasecmp(serdes_comp, "serdes-10g")) { 162 serdes = SERDES_10G; 163 break; 164 } 165 } 166 } 167 168 return serdes; 169 } 170 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org