FEC auto determination

[longhuan-cisco]

FEC mode is a critical configuration for a port, which needs to be configured properly for the port to come up.

There are below scenarios that can end up with wrong FEC mode:

1. In DPB(Dynamic Port Breakout) case, today's DPB CLI doesn't generate FEC config for newly created ports, FEC mode is default to none at SAI/SDK layer.
2. In non-DPB case,
   • Some platforms have no FEC configured in CONFIG_DB by default. The FEC mode can be either default to none at SAI/SDK layer or manually configured by user who might not have enough domain knowledge.
   • Some platforms have default FEC defined in port_config.ini, which however might not be suitable for the specific port/optics on the system.

The feature in this document is to address the issue in both of above scenarios in a common platform-independent way, since the rule to determine FEC for a given port/optics is common for all platforms.

[longhuan-cisco]

Add @shyam77git @jaganbal-a

[zhangyanzhao]

community review recording https://zoom.us/rec/share/T8d5F2zsuzrStE5Sj31-cOf5dxOfT7zbS2pjfhhOuTFgwMR2UwHQjfduRIF5joY.IbX5hMETLHTs-3DJ

[lguohan]

we need backward compatibility.

[zhangyanzhao]

@longhuan-cisco can you please help to add the code PRs by referring to #806 ? More info can be found from https://github.com/sonic-net/SONiC/wiki/Becoming-a-contributor

[zhangyanzhao]

@longhuan-cisco does this feature require SAI change?

[longhuan-cisco]

@longhuan-cisco can you please help to add the code PRs by referring to #806 ? More info can be found from https://github.com/sonic-net/SONiC/wiki/Becoming-a-contributor

Some major updates need to be done in HLD as discussed in community review. And code PRs will be added after that.

@longhuan-cisco does this feature require SAI change?

According to the current plan, it's not required.

[zhangyanzhao]

code PR is not ready, move to backlog for future release