tree: git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git master head: 52755b66ddcef2e897778fac5656df18817b59ab commit: 902a66e08ceaadb9a7a1ab3a4f3af611cd1d8cba [13/24] lan743x: correctly handle chips with internal PHY config: x86_64-randconfig-r034-20201111 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project a719eef73ec447b2c5fc8b70f69564a2e0f78e1e) 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 x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id... git remote add netdev-net git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git git fetch --no-tags netdev-net master git checkout 902a66e08ceaadb9a7a1ab3a4f3af611cd1d8cba # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 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 >>): if (phynode) { ^~~~~~~ drivers/net/ethernet/microchip/lan743x_main.c:1049:7: note: uninitialized use occurs here if (!phydev) { ^~~~~~ drivers/net/ethernet/microchip/lan743x_main.c:1030:2: note: remove the 'if' if its condition is always true if (phynode) { ^~~~~~~~~~~~~ drivers/net/ethernet/microchip/lan743x_main.c:1023:27: note: initialize the variable 'phydev' to silence this warning struct phy_device *phydev; ^ = NULL 1 warning generated. vim +1030 drivers/net/ethernet/microchip/lan743x_main.c 23f0703c125be49 Bryan Whitehead 2018-03-05 1018 23f0703c125be49 Bryan Whitehead 2018-03-05 1019 static int lan743x_phy_open(struct lan743x_adapter *adapter) 23f0703c125be49 Bryan Whitehead 2018-03-05 1020 { 23f0703c125be49 Bryan Whitehead 2018-03-05 1021 struct lan743x_phy *phy = &adapter->phy; 6f197fb63850b26 Roelof Berg 2020-05-29 1022 struct device_node *phynode; 23f0703c125be49 Bryan Whitehead 2018-03-05 1023 struct phy_device *phydev; 23f0703c125be49 Bryan Whitehead 2018-03-05 1024 struct net_device *netdev; 23f0703c125be49 Bryan Whitehead 2018-03-05 1025 int ret = -EIO; 23f0703c125be49 Bryan Whitehead 2018-03-05 1026 23f0703c125be49 Bryan Whitehead 2018-03-05 1027 netdev = adapter->netdev; 6f197fb63850b26 Roelof Berg 2020-05-29 1028 phynode = of_node_get(adapter->pdev->dev.of_node); 6f197fb63850b26 Roelof Berg 2020-05-29 1029 6f197fb63850b26 Roelof Berg 2020-05-29 @1030 if (phynode) { 902a66e08ceaadb Sven Van Asbroeck 2020-11-08 1031 /* try devicetree phy, or fixed link */ 6f197fb63850b26 Roelof Berg 2020-05-29 1032 of_get_phy_mode(phynode, &adapter->phy_mode); 6f197fb63850b26 Roelof Berg 2020-05-29 1033 6f197fb63850b26 Roelof Berg 2020-05-29 1034 if (of_phy_is_fixed_link(phynode)) { 6f197fb63850b26 Roelof Berg 2020-05-29 1035 ret = of_phy_register_fixed_link(phynode); 6f197fb63850b26 Roelof Berg 2020-05-29 1036 if (ret) { 6f197fb63850b26 Roelof Berg 2020-05-29 1037 netdev_err(netdev, 6f197fb63850b26 Roelof Berg 2020-05-29 1038 "cannot register fixed PHY\n"); 6f197fb63850b26 Roelof Berg 2020-05-29 1039 of_node_put(phynode); 6f197fb63850b26 Roelof Berg 2020-05-29 1040 goto return_error; 6f197fb63850b26 Roelof Berg 2020-05-29 1041 } 6f197fb63850b26 Roelof Berg 2020-05-29 1042 } 6f197fb63850b26 Roelof Berg 2020-05-29 1043 phydev = of_phy_connect(netdev, phynode, 6f197fb63850b26 Roelof Berg 2020-05-29 1044 lan743x_phy_link_status_change, 0, 6f197fb63850b26 Roelof Berg 2020-05-29 1045 adapter->phy_mode); 6f197fb63850b26 Roelof Berg 2020-05-29 1046 of_node_put(phynode); 902a66e08ceaadb Sven Van Asbroeck 2020-11-08 1047 } 902a66e08ceaadb Sven Van Asbroeck 2020-11-08 1048 902a66e08ceaadb Sven Van Asbroeck 2020-11-08 1049 if (!phydev) { 902a66e08ceaadb Sven Van Asbroeck 2020-11-08 1050 /* try internal phy */ 23f0703c125be49 Bryan Whitehead 2018-03-05 1051 phydev = phy_find_first(adapter->mdiobus); 23f0703c125be49 Bryan Whitehead 2018-03-05 1052 if (!phydev) 23f0703c125be49 Bryan Whitehead 2018-03-05 1053 goto return_error; 23f0703c125be49 Bryan Whitehead 2018-03-05 1054 902a66e08ceaadb Sven Van Asbroeck 2020-11-08 1055 adapter->phy_mode = PHY_INTERFACE_MODE_GMII; 23f0703c125be49 Bryan Whitehead 2018-03-05 1056 ret = phy_connect_direct(netdev, phydev, 23f0703c125be49 Bryan Whitehead 2018-03-05 1057 lan743x_phy_link_status_change, 6f197fb63850b26 Roelof Berg 2020-05-29 1058 adapter->phy_mode); 23f0703c125be49 Bryan Whitehead 2018-03-05 1059 if (ret) 23f0703c125be49 Bryan Whitehead 2018-03-05 1060 goto return_error; 6f197fb63850b26 Roelof Berg 2020-05-29 1061 } 23f0703c125be49 Bryan Whitehead 2018-03-05 1062 23f0703c125be49 Bryan Whitehead 2018-03-05 1063 /* MAC doesn't support 1000T Half */ 41124fa64d4b298 Andrew Lunn 2018-09-12 1064 phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT); 23f0703c125be49 Bryan Whitehead 2018-03-05 1065 23f0703c125be49 Bryan Whitehead 2018-03-05 1066 /* support both flow controls */ af8d9bb2f2f405a Andrew Lunn 2018-09-12 1067 phy_support_asym_pause(phydev); 23f0703c125be49 Bryan Whitehead 2018-03-05 1068 phy->fc_request_control = (FLOW_CTRL_RX | FLOW_CTRL_TX); 23f0703c125be49 Bryan Whitehead 2018-03-05 1069 phy->fc_autoneg = phydev->autoneg; 23f0703c125be49 Bryan Whitehead 2018-03-05 1070 23f0703c125be49 Bryan Whitehead 2018-03-05 1071 phy_start(phydev); 23f0703c125be49 Bryan Whitehead 2018-03-05 1072 phy_start_aneg(phydev); 23f0703c125be49 Bryan Whitehead 2018-03-05 1073 return 0; 23f0703c125be49 Bryan Whitehead 2018-03-05 1074 23f0703c125be49 Bryan Whitehead 2018-03-05 1075 return_error: 23f0703c125be49 Bryan Whitehead 2018-03-05 1076 return ret; 23f0703c125be49 Bryan Whitehead 2018-03-05 1077 } 23f0703c125be49 Bryan Whitehead 2018-03-05 1078 :::::: The code at line 1030 was first introduced by commit :::::: 6f197fb63850b26ef8f70f1bfe5900e377910a5a lan743x: Added fixed link and RGMII support :::::: TO: Roelof Berg <rberg(a)berg-solutions.de&gt; :::::: CC: David S. Miller <davem(a)davemloft.net&gt; --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org