Hi Vlad, FYI, the error/warning still remains. tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master head: 07f7e57c63aaa2afb4ea31edef05e08699a63a00 commit: c7b9038d8af68e351e09a8427fa0264be8dc811f [8485/11103] net/mlx5e: TC preparation refactoring for routing update event config: x86_64-randconfig-r023-20210214 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project c9439ca36342fb6013187d0a69aef92736951476) 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/next/linux-next.git/commi... git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git git fetch --no-tags linux-next master git checkout c7b9038d8af68e351e09a8427fa0264be8dc811f # 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 >>): In file included from drivers/net/ethernet/mellanox/mlx5/core/en_main.c:45: In file included from drivers/net/ethernet/mellanox/mlx5/core/en_tc.h:40: int mlx5e_tc_tun_update_header_ipv6(struct mlx5e_priv *priv, ^ drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.h:78:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int mlx5e_tc_tun_update_header_ipv6(struct mlx5e_priv *priv, ^ static 1 warning generated. -- In file included from drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c:41: drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:34:1: warning: no previous prototype for function 'mlx5_esw_indir_table_init' [-Wmissing-prototypes] mlx5_esw_indir_table_init(void) ^ drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:33:1: note: declare 'static' if the function is not intended to be used outside of this translation unit struct mlx5_esw_indir_table * ^ static drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:40:1: warning: no previous prototype for function 'mlx5_esw_indir_table_destroy' [-Wmissing-prototypes] mlx5_esw_indir_table_destroy(struct mlx5_esw_indir_table *indir) ^ drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:39:1: note: declare 'static' if the function is not intended to be used outside of this translation unit void ^ static drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:61:1: warning: no previous prototype for function 'mlx5_esw_indir_table_needed' [-Wmissing-prototypes] mlx5_esw_indir_table_needed(struct mlx5_eswitch *esw, ^ drivers/net/ethernet/mellanox/mlx5/core/esw/indir_table.h:60:1: note: declare 'static' if the function is not intended to be used outside of this translation unit bool ^ static In file included from drivers/net/ethernet/mellanox/mlx5/core/eswitch_offloads.c:50: In file included from drivers/net/ethernet/mellanox/mlx5/core/en_tc.h:40: int mlx5e_tc_tun_update_header_ipv6(struct mlx5e_priv *priv, ^ drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.h:78:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int mlx5e_tc_tun_update_header_ipv6(struct mlx5e_priv *priv, ^ static 4 warnings generated. vim +/mlx5e_tc_tun_update_header_ipv6 +78 drivers/net/ethernet/mellanox/mlx5/core/en/tc_tun.h 53 54 int mlx5e_tc_tun_init_encap_attr(struct net_device *tunnel_dev, 55 struct mlx5e_priv *priv, 56 struct mlx5e_encap_entry *e, 57 struct netlink_ext_ack *extack); 58 59 int mlx5e_tc_tun_create_header_ipv4(struct mlx5e_priv *priv, 60 struct net_device *mirred_dev, 61 struct mlx5e_encap_entry *e); 62 int mlx5e_tc_tun_update_header_ipv4(struct mlx5e_priv *priv, 63 struct net_device *mirred_dev, 64 struct mlx5e_encap_entry *e); 65 66 #if IS_ENABLED(CONFIG_INET) && IS_ENABLED(CONFIG_IPV6) 67 int mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv, 68 struct net_device *mirred_dev, 69 struct mlx5e_encap_entry *e); 70 int mlx5e_tc_tun_update_header_ipv6(struct mlx5e_priv *priv, 71 struct net_device *mirred_dev, 72 struct mlx5e_encap_entry *e); 73 #else 74 static inline int 75 mlx5e_tc_tun_create_header_ipv6(struct mlx5e_priv *priv, 76 struct net_device *mirred_dev, 77 struct mlx5e_encap_entry *e) { return -EOPNOTSUPP; } 79 struct net_device *mirred_dev, 80 struct mlx5e_encap_entry *e) 81 { return -EOPNOTSUPP; } 82 #endif 83 int mlx5e_tc_tun_route_lookup(struct mlx5e_priv *priv, 84 struct mlx5_flow_spec *spec, 85 struct mlx5_flow_attr *attr); 86 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org