int mlx5_core_attach_mcg(struct mlx5_core_dev *dev, union ib_gid *mgid, u32 qpn)
 {
-       u32 out[MLX5_ST_SZ_DW(attach_to_mcg_out)] = {0};
-       u32 in[MLX5_ST_SZ_DW(attach_to_mcg_in)]   = {0};
+       u32 in[MLX5_ST_SZ_DW(attach_to_mcg_in)] = {};
        void *gid;
 
        MLX5_SET(attach_to_mcg_in, in, opcode, MLX5_CMD_OP_ATTACH_TO_MCG);
        MLX5_SET(attach_to_mcg_in, in, qpn, qpn);
        gid = MLX5_ADDR_OF(attach_to_mcg_in, in, multicast_gid);
        memcpy(gid, mgid, sizeof(*mgid));
-       return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
+       return mlx5_cmd_exec_in(dev, attach_to_mcg, in);
 }
 EXPORT_SYMBOL(mlx5_core_attach_mcg);
 
 int mlx5_core_detach_mcg(struct mlx5_core_dev *dev, union ib_gid *mgid, u32 qpn)
 {
-       u32 out[MLX5_ST_SZ_DW(detach_from_mcg_out)] = {0};
-       u32 in[MLX5_ST_SZ_DW(detach_from_mcg_in)]   = {0};
+       u32 in[MLX5_ST_SZ_DW(detach_from_mcg_in)] = {};
        void *gid;
 
        MLX5_SET(detach_from_mcg_in, in, opcode, MLX5_CMD_OP_DETACH_FROM_MCG);
        MLX5_SET(detach_from_mcg_in, in, qpn, qpn);
        gid = MLX5_ADDR_OF(detach_from_mcg_in, in, multicast_gid);
        memcpy(gid, mgid, sizeof(*mgid));
-       return mlx5_cmd_exec(dev, in, sizeof(in), out, sizeof(out));
+       return mlx5_cmd_exec_in(dev, detach_from_mcg, in);
 }
 EXPORT_SYMBOL(mlx5_core_detach_mcg);