Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
Calulcate subport values and fix key error in hwsku.json (#18499)
Automatically populate the correct subport value for an interface and insert into config_db.json
Why I did it
Problem 1
Breakouts of optic CMIS modules are broken. For example when in breakout mode of 4x100G on a port the /3, /5, /7 are not correctly associating with lanes (3,4), (5,6) and (7,8) of the transceiver respectively. The /3, /5, /7 are all trying to reprogram lanes (1,2).
In the xcvrd logs we see the following lane masks for all 4 interfaces for a port in 4x100G-2 mode:
EthernetX/X: Setting host_lanemask=0x3
EthernetX/X: Setting media_lanemask=0x1
As a result, we only see the /1 interface linking up correctly, the other 3 interfaces do not have the correct application advertisement + lanemasks applied. This is what we should expect to see:
lanes (1,2)
EthernetX/1: Setting host_lanemask=0x3
EthernetX/1: Setting media_lanemask=0x1
lanes (3,4)
EthernetX/3: Setting host_lanemask=0xc
EthernetX/3: Setting media_lanemask=0x2
lanes (5,6)
EthernetX/5: Setting host_lanemask=0x30
EthernetX/5: Setting media_lanemask=0x4
lanes (7,8)
EthernetX/7: Setting host_lanemask=0xc0
EthernetX/7: Setting media_lanemask=0x8
The problem is that “subport” is expected and used in xcvrd, xcvrd unit tests and explained in the Port Breakout HLD ; it was not implemented and does not end up in DB as expected, which defaults this value to 0.
(Pdb) self.port_dict["Ethernet194"]
{'index': 25, 'speed': '100000', 'lanes': '451,452', 'admin_status': 'up', 'cmis_state': 'INSERTED', 'cmis_retries': 0, 'cmis_expired': None}
Problem 2
This Pull Request does not play well with all HWSKUs that define breakouts. It does a lookup for every child port in the hwsku.json file - There should be 1 default breakout mode for each front panel port - this change expects every child port in a front panel port to have an entry - which causes an exception. Right now as far as I can tell this will break a lot of HWSKUs in a breakout config.
For example this is what the Dynamic Port Breakout feature uses on an Arista SKU to define 2x200G on the first front panel port:
"Ethernet0": {
"default_brkout_mode": "2x200G[100G,50G,40G,25G,10G]"
},
but it currently expects:
"Ethernet0": {
...
},
"Ethernet4": {
...
},
How I did it
Calculate subport value automatically based on the number of child ports used per front panel port and insert it into CONFIG_DB for the interface. If that number is 1 for the front panel, subport 0 is used. If has more than 1 I.e. is in breakout mode use a 1 based subport number as the feature expects. For example:
1x400G-8:
Ethernet0: subport 0
4x100G-2:
Ethernet0: subport 1
Ethernet2: subport 2
Ethernet4: subport 3
Ethernet6: subport 4
I have kept it compatible with Mellanox change - if you want to define a different subport number in your hwsku.json that is fine and it will override the dynamically generated default.
How to verify it
I verified this by checking the output of sonic-cfggen, updating config_db. and checking that both the host and media lane masks were correct for a 400GBASE-DR4 xcvr in both 2x200G-4 mode and 4x100G-2 mode.
All links came up and xcvrd prints the correct lanemasks in logs.
I also made sure that portconfig.py no longer causes an exception; it only checks for the optional HWSKU value if childports are present in hwsku.json file (this is to make sure we don't break Mellanox hwsku's)
I also changed the unit test for config_db generation and ensured the correct values match. The test passes.- Loading branch information
1 parent
53966e3
commit 2c69277