Re: [Linuxptp-users] One-step sync and P2P mode issue

[Richard C. <ric...@gm...>]

On Wed, Sep 03, 2014 at 12:29:05AM +0000, Keller, Jacob E wrote:
> 
> I do not know if one-step mode is specific to SYNC packets or should handle any transmit timestamps. Richard, do you know?

One-step is for Sync messages only. The standard also allows one-step
on Pdelay_Resp messages, but this is not implemented in the Linux
kernel, and I don't know of any hardware implementations either.
 
> You may have to check these. At any rate, I believe we already implement packet filters which will do this for you very efficiently.

Right, the BPF can classify packets, but identifying Sync packets
requires a bit more code. See the helper function is_sync() in
drivers/net/phy/dp83640.c in the Linux kernel sources.

Thanks,
Richard