++ PHY Experts From: Jose Abreu <joab...@synopsys.com> Date: Aug/07/2019, 16:46:23 (UTC+00:00)
> Hello, > > I've some sample code for Clause 73 support using Synopsys based XPCS > but I would like to clarify some things that I noticed. > > I'm using USXGMII as interface and a single SERDES that operates at 10G > rate but MAC side is working at 2.5G. Maximum available bandwidth is > therefore 2.5Gbps. > > So, I configure USXGMII for 2.5G mode and it works but if I try to limit > the autoneg abilities to 2.5G max then it never finishes: > # ethtool enp4s0 > Settings for enp4s0: > Supported ports: [ ] > Supported link modes: 1000baseKX/Full > 2500baseX/Full > Supported pause frame use: Symmetric Receive-only > Supports auto-negotiation: Yes > Supported FEC modes: Not reported > Advertised link modes: 1000baseKX/Full > 2500baseX/Full > Advertised pause frame use: Symmetric Receive-only > Advertised auto-negotiation: Yes > Advertised FEC modes: Not reported > Speed: Unknown! > Duplex: Unknown! (255) > Port: MII > PHYAD: 0 > Transceiver: internal > Auto-negotiation: on > Supports Wake-on: ug > Wake-on: d > Current message level: 0x0000003f (63) > drv probe link timer ifdown ifup > Link detected: no > > When I do not limit autoneg and I say that maximum limit is 10G then I > get Link Up and autoneg finishes with this outcome: > # ethtool enp4s0 > Settings for enp4s0: > Supported ports: [ ] > Supported link modes: 1000baseKX/Full > 2500baseX/Full > 10000baseKX4/Full > 10000baseKR/Full > Supported pause frame use: Symmetric Receive-only > Supports auto-negotiation: Yes > Supported FEC modes: Not reported > Advertised link modes: 1000baseKX/Full > 2500baseX/Full > 10000baseKX4/Full > 10000baseKR/Full > Advertised pause frame use: Symmetric Receive-only > Advertised auto-negotiation: Yes > Advertised FEC modes: Not reported > Link partner advertised link modes: 1000baseKX/Full > 2500baseX/Full > 10000baseKX4/Full > 10000baseKR/Full > Link partner advertised pause frame use: Symmetric Receive-only > Link partner advertised auto-negotiation: Yes > Link partner advertised FEC modes: Not reported > Speed: 2500Mb/s > Duplex: Full > Port: MII <- Never mind this, it's a SW issue > PHYAD: 0 > Transceiver: internal > Auto-negotiation: on > Supports Wake-on: ug > Wake-on: d > Current message level: 0x0000003f (63) > drv probe link timer ifdown ifup > Link detected: yes > > I was expecting that, as MAC side is limited to 2.5G, I should set in > phylink the correct capabilities and then outcome of autoneg would only > have up to 2.5G modes. Am I wrong ? > > --- > Thanks, > Jose Miguel Abreu --- Thanks, Jose Miguel Abreu
