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

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

On Thu, Aug 14, 2014 at 06:07:29AM +0000, Sriharsha Basavapatna wrote:
> May be I didn't explain it clearly earlier.
> 
> I understand one-step mode is where HW support is needed and our hardware does
> insert the timestamp. But because the protocol stack sets the SKBTX_HW_TSTAMP
> bit in the skb, the driver (which is supposed to return the tx timestamp back
> up the stack based on this flag) can't distinguish this as a special case for

Yes, it can.

	/*
	 * Enables time stamping for outgoing packets just as
	 * HWTSTAMP_TX_ON does, but also enables time stamp insertion
	 * directly into Sync packets. In this case, transmitted Sync
	 * packets will not received a time stamp via the socket error
	 * queue.
	 */
	HWTSTAMP_TX_ONESTEP_SYNC,

Thanks,
Richard