Layer 2 link errors when trying to connect ConnectX-5 and Xilinx FPGA

we are trying to connect xilinx VCU108 FPGA to mellanox ConnectX-5 NIC.

a loopback works with both the FPGA and the ConnectX-5, but when connecting the two of them the link goes down, and the interface shows speed and duplex errors.

the mellanox card supports autonegotiation but since the FPGA doesn’t we disabled it and manually set the speed to 100G and duplex to full using the following commands on ubuntu linux.


sudo ifconfig enp9s0 down

sudo ethtool -s enp9s0 speed 100000 duplex full autoneg off

sudo ifconfig enp9s0 up

but the mellanox card still shows bad speed and duplex and the link is down


snk14@snk14:~$ sudo ethtool enp9s0

Settings for enp9s0:

Supported ports: [ FIBRE ]

Supported link modes: 1000baseKX/Full

10000baseKR/Full

40000baseKR4/Full

40000baseCR4/Full

40000baseSR4/Full

40000baseLR4/Full

25000baseCR/Full

25000baseKR/Full

25000baseSR/Full

50000baseCR2/Full

50000baseKR2/Full

100000baseKR4/Full

100000baseSR4/Full

100000baseCR4/Full

100000baseLR4_ER4/Full

Supported pause frame use: Symmetric

Supports auto-negotiation: Yes

Supported FEC modes: Not reported

Advertised link modes: 100000baseKR4/Full

100000baseSR4/Full

100000baseCR4/Full

100000baseLR4_ER4/Full

Advertised pause frame use: Symmetric

Advertised auto-negotiation: No

Advertised FEC modes: Not reported

Speed: Unknown!

Duplex: Unknown! (255)

Port: FIBRE

PHYAD: 0

Transceiver: internal

Auto-negotiation: off

Supports Wake-on: d

Wake-on: d

Current message level: 0x00000004 (4)

link

Link detected: no

are there any other nobes that i need to tweak?

any recommendations?

Thanks.

Hello Mnehi

Are you using a supported cable ? Please update the case with your cable part/transceiver number.

Please see: http://www.mellanox.com/pdf/firmware/ConnectX5-FW-16_25_1020-release_notes.pdf

1.2 Supported Cables and Modules

Yes, you would have to set the speed and duplex manually for the nic in this instance because there is no switch to auto-negotiate from.

Many thanks,

Cheers,

~Steve