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saysai's avatar
saysai
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2 years ago

PCIe PTM time adjustment

Hi,

We are using "Intel(R) Xeon(R) E-2334 CPU @ 3.40GHz" processor to test PCIe PTM with a third party PCIe NIC card. We see that PTM is supported on the PCI bridge (below is the lspci output)

00:00.0 Host bridge: Intel Corporation Device 4c63 (rev 01)

00:01.0 PCI bridge: Intel Corporation Device 4c01 (rev 01)

lspci -d :4c01 -vv

...

Capabilities: [150 v1] Precision Time Measurement

PTMCap: Requester:- Responder:+ Root:+

PTMClockGranularity: 4ns

PTMControl: Enabled:+ RootSelected:+

PTMEffectiveGranularity: Unknown

...

We found that the PTM time is showing the "uptime" of the x86 system(say 4 days). We read this using ART time using sample program using "rdtsc" instruction from x86. How can we synchronize x86 system time to PCIe PTM? so that the PTM requester sees the x86 system time in the PTM messages.

Please let us know any further information is required in this regard.

8 Replies

  • Allan_A_Intel's avatar
    Allan_A_Intel
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    2 years ago

    Dear saysai,


    Thank you for reaching out to us regarding your query about synchronizing the x86 system time with PCIe PTM. We appreciate your detailed description of the issue and would be glad to assist you.


    To begin with, it's important to note that the synchronization of x86 system time with PCIe PTM is primarily handled by the operating system and the software components involved in the process. The processor itself, such as the Intel® Xeon® E-2334 Processor in your case, does not directly impact this synchronization.


    To better understand your setup and provide you with accurate guidance, we kindly request the following information:


    1. Motherboard Brand and Model: Please provide the brand and model of the motherboard you are using.
    2. Third Party PCIe NIC Card: Kindly specify the brand and model of the PCIe NIC card you are using. This detail will enable us to gather specific information about the card's compatibility.
    3. Operating System: Please let us know the operating system installed on your x86 system.


    We appreciate your patience, and we look forward to assisting you further.


    Best regards,


    Allan A.

    Intel Customer Support


    • saysai's avatar
      saysai
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      2 years ago

      Dear Allan,

      Thanks for the response. First of all I would like to clarify regarding my original query as given below.

      We want to synchronize PCIe PTM time with x86 system time, so that PCIe PTM dialogues from x86 PTM responder carry the x86 system time rather than time (UP time) maintained by ART timer. So is there anyway to program ART timer with x86 system time (or) use the system time source as input to PCIe PTM block.

      Here are the replies to your queries:

      1. Motherboard Brand and Model: Please provide the brand and model of the motherboard you are using. >> DELL PowerEdge T150
      2. Third Party PCIe NIC Card: Kindly specify the brand and model of the PCIe NIC card you are using. This detail will enable us to gather specific information about the card's compatibility. >> We are using FPGA NIC card to test the PTM functionality.
      3. Operating System: Please let us know the operating system installed on your x86 system >> Ubuntu 20.04.4 LTS

      Thanks,

      Sai

  • Allan_A_Intel's avatar
    Allan_A_Intel
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    2 years ago

    Dear Sai,


    Thank you for providing clarification regarding your request. We understand the importance of receiving prompt assistance for your specific issues. To ensure a faster resolution, we have a dedicated forum specifically tailored to address these concerns.


    I am pleased to inform you that I am moving this thread to the appropriate forum. By doing so, your inquiry will receive the attention it deserves from our experts in that area. They will be better equipped to assist you and provide the necessary guidance.


    We appreciate your understanding and cooperation as we work diligently to address your concerns. Should you have any additional questions or require further assistance, please feel free to reach out. We are here to help.


    Thank you once again for reaching out to us, and we look forward to assisting you further in the dedicated forum.


    Best regards,


    Allan A.

    Intel Customer Support


  • saysai's avatar
    saysai
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    2 years ago

    Dear Allan,

    Any further updates on this from forums?

    Thanks,

    Sai

    • saysai's avatar
      saysai
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      2 years ago

      Dear Allan,

      Any further updates on this from forums?

      Thanks,

      Sai

  • JulianStj's avatar
    JulianStj
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    2 years ago

    Hi Saysai,

    I've done quite a bit work on PTM with different hardware. You typically use phc2sys to copy to or from CLOCK_REALTIME, which is the kernel's projection of the relationship between the ART in the CPU (read via TSC) and the other clock used in phc2sys. Let me know if you'd like more details, I can send you my contact info.

    Thanks!

    -Julian St. James

  • saysai's avatar
    saysai
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    2 years ago

    Thanks Julian for the response..

    Apologies for delayed reply, as i missed to watch your reply. Please share your contact info. Thanks for the support.

    Thanks,

    Sai

  • JulianStj's avatar
    JulianStj
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    2 years ago

    Hi Sai,

    No problem, you can reach me at my email which is listed on the OCP TAP website, where Kevin and I are working to develop and support PTM.

    https://www.opencompute.org/wiki/PTM_Readiness

    Thank you!

    -Julian