SAI_TUNNEL_ATTR_DECAP_DSCP_MODE meta_generic_validation_set error

[jipanyang]

SAI_TUNNEL_ATTR_DECAP_DSCP_MODE is a create only attribute, while orchagent provided set interface for it.

https://github.com/Azure/sonic-swss/blob/136621b497d8a51577c7a33e67c7d0fb68a04f2d/orchagent/tunneldecaporch.cpp#L423

Aug 17 21:06:41.890270 sonic NOTICE swss/swssconfig: :- main: Loading config from JSON file:./ipinip.json...
Aug 17 21:06:41.892999 sonic ERR swss/orchagent: :- meta_generic_validation_set: SAI_TUNNEL_ATTR_DECAP_DSCP_MODE:SAI_ATTR_VALUE_TYPE_INT32 attr is create only and cannot be modified
Aug 17 21:06:41.892999 sonic ERR swss/orchagent: :- setTunnelAttribute: Failed to set attribute dscp_mode with value pipe
Aug 17 21:06:41.892999 sonic ERR swss/orchagent: :- addDecapTunnelTermEntries: 11.161.62.196 already exists. Did not create entry.

    /**
     * @brief Tunnel DSCP mode (pipe or uniform model)
     *
     * Default SAI_TUNNEL_DSCP_MODE_UNIFORM_MODEL
     *
     * @type sai_tunnel_dscp_mode_t
     * @flags MANDATORY_ON_CREATE | CREATE_ONLY
     * @condition SAI_TUNNEL_ATTR_TYPE == SAI_TUNNEL_TYPE_IPINIP or SAI_TUNNEL_ATTR_TYPE == SAI_TUNNEL_TYPE_IPINIP_GRE
     */
    SAI_TUNNEL_ATTR_DECAP_DSCP_MODE,

[lguohan]

this can be sai forum question, does it make sense to change to CREATE_AND_SET?

[jipanyang]

If ASIC supports Tunnel DSCP mode change on the fly, it is good to modify the attribute to CREATE_AND_SET.