On Fri, 31 May 2019 at 19:09, Richard Cochran [off-list ref] wrote:

On Fri, May 31, 2019 at 06:23:34PM +0300, Vladimir Oltean wrote:

quoted

You mean to queue it and subvert DSA's own RX timestamping callback?

No, use the callback.

quoted

Why would I do that? Just so as not to introduce my .can_timestamp
callback?

Right, the .can_timestamp is unneeded, AFAICT.

quoted

quoted

Now I'm starting to understand your series.  I think it can be done in
simpler way...

sja1105_rcv_meta_state_machine - can and should be at the driver level
and not at the port level.

Can: yes. Should: why?

To keep it simple and robust.

quoted

One important aspect makes this need be a little bit more complicated:
reconstructing these RX timestamps.
You see, there is a mutex on the SPI bus, so in practice I do need the
sja1105_port_rxtstamp_work for exactly this purpose - to read the
timestamping clock over SPI.

Sure.  But you schedule the work after a META frame.  And no busy
waiting is needed.

Ok, I suppose this could work.
But now comes the question on what to do on error cases - the meta
frame didn't arrive. Should I just drop the skb waiting for it? Right
now I "goto rcv_anyway" - which linuxptp doesn't like btw.

Thanks,
Richard