Re: [Linuxptp-users] High Propagation Time

[André S. <and...@gm...>]

On Thu, Aug 9, 2018 at 4:37 AM, Richard Cochran <ric...@gm...>
wrote:

> On Tue, Aug 07, 2018 at 02:57:40PM +0200, André Sadie wrote:
> > Is the 7μs really as unreasonable as I think?
>
> Yes.
>
> > Any recommendations on how to proceed?
>
> Does this device support HW time stamping at all?  (ethtool -T)
>
> If not, it won't work well for gPTP.
> If so, then something is really wrong.
>
> I would stick with the i210...
>

The device does support HW timestamping, see 'ethtool -T' output below.
Also if I force software timestamping the propagation delay is much higher
and varies between 30μs to 150μs.

>From 'ethtool -T'
Time stamping parameters for eno1:
Capabilities:
    hardware-transmit     (SOF_TIMESTAMPING_TX_HARDWARE)
    software-transmit     (SOF_TIMESTAMPING_TX_SOFTWARE)
    hardware-receive      (SOF_TIMESTAMPING_RX_HARDWARE)
    software-receive      (SOF_TIMESTAMPING_RX_SOFTWARE)
    software-system-clock (SOF_TIMESTAMPING_SOFTWARE)
    hardware-raw-clock    (SOF_TIMESTAMPING_RAW_HARDWARE)
PTP Hardware Clock: 0
Hardware Transmit Timestamp Modes:
    off                   (HWTSTAMP_TX_OFF)
    on                    (HWTSTAMP_TX_ON)
Hardware Receive Filter Modes:
    none                  (HWTSTAMP_FILTER_NONE)
    all                   (HWTSTAMP_FILTER_ALL)
    ptpv1-l4-sync         (HWTSTAMP_FILTER_PTP_V1_L4_SYNC)
    ptpv1-l4-delay-req    (HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ)
    ptpv2-l4-sync         (HWTSTAMP_FILTER_PTP_V2_L4_SYNC)
    ptpv2-l4-delay-req    (HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ)
    ptpv2-l2-sync         (HWTSTAMP_FILTER_PTP_V2_L2_SYNC)
    ptpv2-l2-delay-req    (HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ)
    ptpv2-event           (HWTSTAMP_FILTER_PTP_V2_EVENT)
    ptpv2-sync            (HWTSTAMP_FILTER_PTP_V2_SYNC)
    ptpv2-delay-req       (HWTSTAMP_FILTER_PTP_V2_DELAY_REQ)

Thank you,
Andre.