On Wed, Jun 3, 2020 at 3:48 AM Slava Ovsiienko [off-list ref] wrote:

quoted

From: PATRICK KEROULAS <redacted>
* rdma-code, libibverbs-dev: 28.0
* NIC Part Number:      MCX516A-CDA_Ax
* ConnectX-5 Ex EN
* FW: 16.25.1020

It looks like outdated firmware, please:
- update the firmware - at least 16.27.2008 is GA. I would recommend to install OFED - it updates the FW
- make sure the UCTX_EN option in FW configuration is set to "true"

Hello Slava,

I managed to query device_frequency_khz by simply setting UCTX_EN=1,
convert the mbuf->timestamp to nsec and write a pcap. However, the
accuracy is quite disappointing, compared to libvma or even SW TS.

The freq value looks constant (=78125kHz). Correct me if I'm wrong, a
ptp client is supposed to continuously adjust some kind of VCO on the
NIC. And even setting a crazy value through /dev/ptp interface manually
doesn't affect device_frequency_khz. Please could you clarify?

This leads me back to mlx5dv_clock_info->nsec. If this is a valid method,
I think the only missing piece is to access it from the secondary process,
which implies to share ibv_context.

Best Regards,

PK