Huge delay when retrieving a hardware transmission timestamp

[Martin42]

Dear network card friends,

I use one network card of type Intel E810-XXVDA2 because it has the feature
to provide a timestamp for each outgoing packet, i.e. network card generates
the timestamp when it transmits the packet (hardware transmission timestamping).

In principle, that retrieval of hardware transmission timestamps works
for my application under Linux (Linux kernel 5.17.12).
I use the socket API to configure
hardware timestaping, i.e. setsockopt() with SOF_TIMESTAMPING_RAW_HARDWARE,
SOF_TIMESTAMPING_TX_HARDWARE and SOF_TIMESTAMPING_OPT_TSONLY.
Then, the MSG_ERRQUEUE provides a control message with SCM_TIMESTAMPING field
that contains the hardware transmission timestamp. So far so good.

The problem is that my applications is blocked by the retrieval of the hardware transmission timestamp
for about 250 microseconds or more. That delay is unacceptable for
my application. I wonder where that delay comes from.

Is this is a problem of the network card or is it a problem of the driver or is it a problem with my application?
Has anyone experienced such huge delays when getting the hardware transmission timestamp?
If not, what do you do in order to retrieve the hardware transmission timestamps?
Does anyone know how to fix the delay?

[Irwan_Intel]

Hello Martin42,

Thank you for the posting in Intel Ethernet Communities.

In order to provide further assistance, could you please provide additional information about your system and the applications you are using? 

This will help us better understand your inquiry and offer appropriate support.

You could share the SSU log with us as well.

https://www.intel.com/content/www/us/en/support/articles/000008563/ethernet-products.html

Regards,

Irwan_Intel

[Irwan_Intel]

Hello Martin42,

I wished to follow up regarding this post.

Please let me know if you able to provide the info as requested.

Regards,

Irwan_Intel

[Martin42]

Hello Irwan_Intel,

I need to some time to provide info.

Regards,

Martin

[Irwan_Intel]

Hello Martin42,

I wished to follow up regarding this post.

Please share the information for further checking.

Regards,

Irwan_Intel

[Martin42]

Hello Irwan_Intel,

I have found the Linux kernel mailing list about development of Intel Wired LAN adapters:

https://lists.osuosl.org/mailman/listinfo/intel-wired-lan

You find details about my hardware in the following posts:

https://lists.osuosl.org/pipermail/intel-wired-lan/Week-of-Mon-20240212/039667.html

https://lists.osuosl.org/pipermail/intel-wired-lan/Week-of-Mon-20240219/039748.html

Is that mailing list the right place for my problem or can you recommend a more suitable place?

Do you have any contact to a software developer for the Linux kernel driver of the Intel E810 card who you can forward my hardware/software issue?

Kind regards,

Martin

[Irwan_Intel]

Hello Martin42,

As per our checking, this doesn't seem like official intel mailing list. However, you may still get support from there as this list is provided from sourceforge for in-kernel driver issues.

Regarding your inquiry on the delay when retrieving hardware transmission timestamp, have you tried latest driver https://sourceforge.net/projects/e1000/files/ice%20stable/ and verify if the issue still persists?

You may also refer to the document as follows for PTP configuration setup:

https://cdrdv2.intel.com/v1/dl/getContent/646265?explicitVersion=true

https://cdrdv2.intel.com/v1/dl/getContent/722960?explicitVersion=true

Regards,

Irwan_Intel

[Irwan_Intel]

Hello Martin42,

I wish to follow up if you still have any further questions regarding the issue.

Regards,

Irwan_Intel

[Irwan_Intel]

Hello Martin42,

Kindly note that as we have not received any response from our previous follow-ups, we will be closing this request.

If you have any more questions in the future, please don't hesitate to post a new question, as this thread will no longer be monitored.

Regards,

Irwan_Intel