Can't get chelsio NIC to work - cxgb4 request_irq failed, err -16

[reckless]

I'm having issues with my T580-LP-CR card. I have it attached to a Mellanox 40G switch. The switch sees the link as up and the light is green. However, the link is DOWN on my server.

root@proxmox:~# ip link set enp67s0f4 up
RTNETLINK answers: Device or resource busy
root@proxmox:~# ip link set enp67s0f4d1 up
RTNETLINK answers: Device or resource busy

In syslog:

Nov 06 02:48:21 proxmox kernel: genirq: Flags mismatch irq 1049. 00000000 (enp67s0f4-Rx0) vs. 00000000 (enp67s0f4-Rx0)
Nov 06 02:48:21 proxmox kernel: cxgb4 0000:43:00.4: request_irq failed, err -16
Nov 06 02:48:25 proxmox kernel: genirq: Flags mismatch irq 1049. 00000000 (enp67s0f4-Rx0) vs. 00000000 (enp67s0f4-Rx0)
Nov 06 02:48:25 proxmox kernel: cxgb4 0000:43:00.4: request_irq failed, err -16

What's going on here?