Re: [Linuxptp-users] Hardware PTP clock synchronization

[Keller, J. E <jac...@in...>]

> -----Original Message-----
> From: Гаврилов Александр [mailto:le...@im...]
> Sent: Monday, August 05, 2013 4:58 AM
> To: lin...@li...
> Subject: Re: [Linuxptp-users] Hardware PTP clock synchronization
> 
> Hello!.
> 
> IntelR 82576 Gigabit Ethernet Controller Datasheet:
> "On both transmit and receive sides the timestamp values are locked in
> registers until values are read by
> software. As a result if a new PTP packet that requires time stamp arrives
> before software access it is
> not time stamped. In some cases in the receive path a packet that was
> timestamped might be lost and
> not reach the host. To avoid a deadlock condition on the time stamp
> registers the software should keep
> a watch dog timer to clear locking of the time stamp register. The interval
> counted by such a timer
> should be at least higher then the expected interval between two Sync or
> Delay_Req packets depends
> on the node state (Master or Slave)."
> 
> How  should  I  modify the source code of igb driver (or ptp4l) to use
> the timer?
> 
> Sincerely, Alexander.
> 

You should not have to modify the 82576 driver code.

- Jake