List: time-nuts@lists.febo.com
From: Wojciech Owczarek
Re: [time-nuts] IEEE 1588 PTP support on raspberry pi 4 compute module
Thu, Oct 22, 2020 10:24 AM
The only way to
attempt at grabbing a TX timestamp sensibly in software is by the kernel,
just before it passes the packet to hardware, and long after the
application "sent" it, and Linux supports this. PTP's Follow-Up message is
transmitted as soon as the TX timestamp is grabbed. This extra dead time is
minimal.