Hi Luiz, 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/Luiz-Angelo-Daros-de-Luca/dt-bin... base: https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git 7e1c5d7b6926f63d3750a273486a143e50d216ad config: arm-randconfig-c002-20211219 (https://download.01.org/0day-ci/archive/20211220/202112202212.PeXrGA7n-lk...) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 4c9e31a4814592bbda7153833e46728dc7b21100) 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/4098c967b9f6635090798d9eb031f57ae... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Luiz-Angelo-Daros-de-Luca/dt-bindings-net-dsa-realtek-smi-mark-unsupported-switches/20211218-171506 git checkout 4098c967b9f6635090798d9eb031f57ae26ed422 # 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/net/dsa/realtek/ kernel/trace/ 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 >>): int realtek_mdio_read_reg(struct realtek_priv *priv, u32 addr, u32 *data) ^ drivers/net/dsa/realtek/realtek-mdio.c:53:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int realtek_mdio_read_reg(struct realtek_priv *priv, u32 addr, u32 *data) ^ static 1 warning generated. vim +/realtek_mdio_read_reg +53 drivers/net/dsa/realtek/realtek-mdio.c 52 54 { 55 u32 phy_id = priv->phy_id; 56 struct mii_bus *bus = priv->bus; 57 58 BUG_ON(in_interrupt()); 59 60 mutex_lock(&bus->mdio_lock); 61 /* Write Start command to register 29 */ 62 bus->write(bus, phy_id, MDC_MDIO_START_REG, MDC_MDIO_START_OP); 63 64 /* Write address control code to register 31 */ 65 bus->write(bus, phy_id, MDC_MDIO_CTRL0_REG, MDC_MDIO_ADDR_OP); 66 67 /* Write Start command to register 29 */ 68 bus->write(bus, phy_id, MDC_MDIO_START_REG, MDC_MDIO_START_OP); 69 70 /* Write address to register 23 */ 71 bus->write(bus, phy_id, MDC_MDIO_ADDRESS_REG, addr); 72 73 /* Write Start command to register 29 */ 74 bus->write(bus, phy_id, MDC_MDIO_START_REG, MDC_MDIO_START_OP); 75 76 /* Write read control code to register 21 */ 77 bus->write(bus, phy_id, MDC_MDIO_CTRL1_REG, MDC_MDIO_READ_OP); 78 79 /* Write Start command to register 29 */ 80 bus->write(bus, phy_id, MDC_MDIO_START_REG, MDC_MDIO_START_OP); 81 82 /* Read data from register 25 */ 83 *data = bus->read(bus, phy_id, MDC_MDIO_DATA_READ_REG); 84 85 mutex_unlock(&bus->mdio_lock); 86 87 return 0; 88 } 89 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org