Are legacy/INTx interrupts known to work on connectx-4 adapters?

I’ve written a driver for OpenBSD that supports connectx-4+ ethernet (equivalent to the mlx5 driver), based on the Programming Reference Manual. While writing this I attempted to use legacy interrupts as we don’t have MSI-X on all hardware platforms, and I never got it to work. MSI-X works as expected on platforms where it’s available.

The PRM refers to legacy interrupt support in a few places, and there doesn’t seem to be any reason it wouldn’t work, but I notice the mlx5 driver will only use MSI-X and will fail to initialize if that doesn’t work. Are legacy interrupts known to work in some configuration?

Hello Jonathan,

Base on our internal datasheet, INTx interrupts is not supported.


• Advanced Error Reporting (AER)

• Access Control Services (ACS)

• Downstream Port Containment (DPC)

• MSI Interrupt support

• RX margin/link maintenance support

Also we had provide freebsd driver, and open source to freebsd. I think more design in issue you can though freebsd community.

And some IC and internal design is not public, you can consult local sales and FAE get design in support.