Can you change the firmware to expose the 802.3 registers for PRBS?
You can then write a library which both plylib and your driver can use.

Andrew,

No, exposing the PRBS registers to drivers is not possible in our design (the registers are buried deep within the Accelerator/NIC/PHY/Analog IP hierarchy).

Additionally, the PHY PRBS registers are not in accordance with the IEEE Clause 45 definitions. For instance, the PRBS registers are paged and 32-bit wide.

Given these constraints, we think ethtool --phy-test is a reasonable starting point for exposing the long-established Ethernet PRBS functionality to Linux userspace, as it aligns well with the driver-owned NIC architecture model. If you think a more generic layered approach would be preferable, we would appreciate guidance on the expected architecture. That would help us better understand the implementation complexity, required effort, and delivery timelines.

Thanks,
Shubham D

-----Original Message-----
From: Andrew Lunn <andrew@lunn.ch>
Sent: 20 June 2026 00:07
To: Das, Shubham <redacted>
Cc: Alexander H Duyck <redacted>; lee@trager.us;
netdev@vger.kernel.org; mkubecek@suse.cz; D H, Siddaraju
[off-list ref]; Chintalapalle, Balaji
[off-list ref]; Lindberg, Magnus
[off-list ref]; niklas.damberg@ericsson.com
Subject: Re: Ethtool : PRBS feature

quoted

The host driver does not directly access any registers but requests
the PHY FW to manage PRBS on behalf of it.

Maybe a dumb question. Why?

Can you change the firmware to expose the 802.3 registers for PRBS?
You can then write a library which both plylib and your driver can use.

	Andrew