Re: [PATCH net-next v4 0/3] Linn Ethernet Packet Sniffer driver

[Richard Cochran <richardcochran@gmail.com>]

On Fri, Feb 27, 2015 at 05:09:24PM +0000, Stathis Voukelatos wrote:
> To summarize (and confirm my understanding) your suggestion is for the
> sniffer to be configured to match PTP packets and (similarly to the
> dp83640) return the Message Type and Sequence Id fields that will allow
> them to be matched to an sk_buf that has been passed from the stack.
> Then the sk_buf can be timestamped using the sniffer timestamp.

Yes.
 
> The H/W does have the capability to do that. However, in order to
> implement it there will be some architectural changes needed
> in the kernel. This module cannot really pretend to be a PHY.
> In the real world it sits between the MAC and the PHY.

Right.

Here is one idea.  Put a link to the TS device in the PHY's DT node.
Then, in phy_probe, check if the PHY's four methods, ts_info,
hwtstamp, rxtstamp, and txtstamp, are all null.  If so, check for a DT
link from the PHY's node to a TS device driver.  If found, then set
the four methods to call into the TS driver's callbacks.

Just off of the top of my head.

Thanks,
Richard