E810-XXVDA4T: ptp4l: large delay reported

[akaanich-technica]

Hi,

Context

I am using the E810-XXVDA4T and doing some PTP measurements.

My setup I connect two ports of the E810-XXVDA4T to each other, and measure the delay.

In my case I want the measure the RX and TX delay of different SFP modules, in order to calculate what egressLatency/ingressLatency needs to be configured for each one.

I am using the automotive profiles 

https://github.com/richardcochran/linuxptp/blob/master/configs/automotive-master.cfg

https://github.com/richardcochran/linuxptp/blob/master/configs/automotive-slave.cfg

The slave is configured in free_running since E810-XXVDA4T have only one PHC.

I am using theE810-XXVDA4T to measure how long it took for each SFP connection (RX+TX) to forward traffic.

ptp4l provides this info as delay measurement in the logs.

I tested multiple SFP modules (always use the same type of SFP connector in both ports).

I tried multiple vendors, and even tried an SFP module where the RX and TX delays were already measured using an oscilloscope.

The Problem

I noticed that there is always an extra delay reported by ptp4l, that is not related to the SFP module itself.

Medium	Product	Delay
Optic	A	502ns
Optic	B	888-961ns
DAC 0.5m	C	450-458ns
1000BaseT1	T	5856ns

* Product C is an interesting measurement, because it's a passive DAC, with no PHY, so should not have any delay at all (short of few nanoseconds from the cable length)
* For the product T, we know using the oscilloscope, that it has a typical delay of (Tx= 567ns, Rx: 4431ns), this means that there are an extra 858ns coming from for the E810-XXVDA4T itself.

Looking at the source code in https://github.com/intel/ethernet-linux-ice/blob/main/src/ice_ptp_consts.h

I see that there is a lot of calibration constants defined for E82X products, but such constants are missing for the E810.
Such calibration is typically always necessary in the driver, and existed even for I210
https://github.com/torvalds/linux/commit/3f544d2a4d5c2d817cfee9e6302fc2909aaef155

I tried to find this calibration data in the Intel documents, but I was not able to find any, I checked:

* Intel Ethernet Network Adapter E810-XXVDA4T Product Brief

* 646265_E810-XXVDA4T User Guide_Rev1.2

* Intel ® Ethernet Controller E810 Datasheet

What I need

* How much egressLatency/ingressLatency should be configured in ptp4l , as far as I know, those numbers change depending on the speed.

Of course, I only need the numbers contributed by the E810-XXVDA4T itself, I can add whatever delay the SFP module is adding on top of that.

I there any plans to introduce those numbers in the driver, similar to how they are done for other products?

thanks in advance.
 

[Vik3]

Hello akaanich-technica,

Thank you for posting on Intel Community. To assist you further, please provide the additional details below.

• Kindly provide us with the complete front and back pictures of the part with the label visible.
• Provide share the SSU Logs (Please refer this guide: Help Guide for the Intel® System Support Utility)
• Please confirm if the NIC was purchased separately or pre-installed.

Regards,

Vikas_Intel

[Vik3]

Hello akaanich-technica,

Greetings for the day!

We are following up to check if you were able to find the information we requested. Kindly confirm at your earliest convenience, so that we can continue assisting you in resolving this matter.

Regards,

Vikas_Intel

[Vik3]

Hello akaanich-technica,

Greetings for the day!

We would like to inform you that we are closing this request due to no response being received for our previous follow-ups. Please don’t hesitate to reach out with any further questions in the future. Feel free to start a new conversation, as this thread will no longer be monitored.

Regards,

Vikas_Intel

[akaanich-technica · Accepted solution]

We managed to fix the issue, upgrading the card firmware from 21.5.9 to latest (24.0.5) fixed the problem.

PS: for some reason I never got email notification for any of the replies to this thread, that's why I failed to reply previously.