Re: Chrony on CM4

I think it's going to be easier to figure out the problem if we have one
side that is known to work. Is NTP-over-PTP known to work on Intel NICs
like i210/i225/i226? If so, then tomorrow I'll try with one side as Intel
NIC and one as CM4.

James

On Mon, Sep 4, 2023 at 8:03 PM James Clark <[email protected]> wrote:

> On Mon, Sep 4, 2023 at 6:51 PM Miroslav Lichvar <[email protected]>
> wrote:
>
>> On Mon, Sep 04, 2023 at 06:30:06PM +0700, James Clark wrote:
>> > "chronyc serverstats" looks good: I'm seeing  increasing "NTP hardware
>> RX
>> > timestamps" and
>> > "NTP hardware TX timestamps".
>>
>> Is the server running on CM4?
>>
>
> Yes.
>
>
>> > I'm now trying two clients, and I see different results with chronyc
>> > ntpdata:
>> >
>> > - another CM4: here I see RX timestamping : Hardware but TX
>> timestamping :
>> > Kernel
>>
>> Can you please enable the measurements log and see if all TX
>> timestamps are kernel or there is a mix of kernel and hardware?
>
>
> It's a mixture: 848 "K H"; 22 "K K"; 13 "H H".
>
>
>> The HW
>> timestamping might be unreliable. You could try increasing hwtstimeout
>> to 1 to wait even longer for the TX timestamp.
>>
>> You could also try adding "minpoll 2" to the hwtimestamp directive to
>> read the clock less frequently to avoid some collisions with the
>> timestamping access. IIRC the HW or driver might have an issue with
>> that.
>>
>
>  I tried increasing both hwtstimeout and minpoll, but it hasn't fixed the
> problem.
>
> > - an x86 box with the AQC107: here I see TX timestamping : Hardware and
>> RX
>> > timestamping : Hardware
>> > but on the client "chronyc ntpdata" shows Kernel for TX timestamping
>> and RX
>> > timestamping.
>>
>> I have no experience with this NIC. What does ethtool -T show?
>>
>
> It shows:
>
> Time stamping parameters for enp1s0:
> Capabilities:
>         hardware-transmit
>         software-transmit
>         hardware-receive
>         software-receive
>         software-system-clock
>         hardware-raw-clock
> PTP Hardware Clock: 3
> Hardware Transmit Timestamp Modes:
>         off
>         on
> Hardware Receive Filter Modes:
>         none
>         ptpv2-l4-event
>         ptpv2-l2-event
>         ptpv2-event
>
> The measurements here are consistently K K, apart from the first one which
> is H H.
>
> James
>
>