Re: [Linuxptp-users] Problems with hardware time stamping with PHY DP83640 on MCP5200 powerpc platform

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

On Wed, May 23, 2012 at 04:54:42PM +0200, Mario Molitor wrote:
> 
> Why the software time stamping work and only the hardware time stamping has
> this problem? This point has me irritated.

SW and HW time stamping are completely different code paths and are
not really connected to each other.

> The other point we don't have connected the PTP server directly with our PTP
> slave module and it is some Ethernet switches involved in Ethernet
> connection. Could this make a problem?

I doubt it.

> >Did you enable CONFIG_DP83640_PHY too?
> 
> Yes we have also used this option.

Good. Can you post your dmesg?

> I have adapt the code of PHY driver (net/phy/dp83640.c) with printk and I
> have seen the probe function is executed. I can say the kernel driver is
> compiled and loaded.

If you want to trace what is happening, you can add printks along the
following path.

*** drivers/net/ethernet/freescale/fec_mpc52xx.c: mpc52xx_fec_rx_interrupt()

	if (!skb_defer_rx_timestamp(skb))
		netif_rx(rskb);

*** net/core/timestamping.c: skb_defer_rx_timestamp[104]

	type = classify(skb);

	(check the conditions within classify() and the returned type)
	...
	       phydev = skb->dev->phydev;
	       	      if (likely(phydev->drv->rxtstamp))
				return phydev->drv->rxtstamp(phydev, skb, type);

*** drivers/net/phy/dp83640.c: dp83640_rxtstamp[1172]

	(If you can trace a sync message this far, then that will
	 already help narrow down the problem.)

Thanks,
Richard