Re: [Linuxptp-users] received SYNC without timestamp

[Martin P. <pec...@fe...>]

>> So it seems the card timestamps FOLLOW_UP and DELAY_RESP packets, but does
>> not timestamp SYNC packets. Why could this be? Can it somehow mismatch SYNC
>> and FOLLOW_UP messages in the chip and stamp the wrong one? (I think
>> FOLLOW_UP stamps are not good for anything, are they?). Or is it still some
>> problem with ptp4l not reading the socket?
> No, no, NO!
>
> The msg_sots_missing() function checks the message type.  It always
> returns FALSE (zero) for non-event messages like FOLLOW_UP.

You're right, Richard, I misunderstood what the if-branch does. So I 
went further in sk.c and verified that the control messages read when 
receiving SYNC packets do not contain the SO_TIMSTAMPING control 
message. I further verified that the setsockopt for SO_TIMESTAMPING 
succeeds and is called with flags=69, which is 
RX_HARDWARE+TX_HARDWARE+RAW_HARDWARE and that the SIOCSHWTSTAMP succeeds 
setting rx_filter 12 (HWTSTAMP_FILTER_PTP_V2_EVENT). So from the setup 
point of view, everything seems correct to me.

Thanks, Martin