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

[Mario M. <Mar...@we...>]

Hi Richard,

>> >I have never seen the combination MPC5200/DP83640. Is this a
>> >commercial board or a custom design?
>>
>> It is custom design. We design a module for our data acquisition systems.
>
> Here are two ideas to think about.
>
> 1. Perhaps the PHY device driver instance is not properly associated with
>   the FEC driver instance. Have you checked your DTS?

We have checked this and it looks ok, but we can't shutout any problem. We 
will very this tomorrow again.


> 2. The PHY sends the time stamps to the MAC using special "status"
>   frames. Perhaps your MAC is dropping these frames? They are sent
>   with a DST MAC address like this:
>
>   static u8 status_frame_dst[6] = { 0x01, 0x1B, 0x19, 0x00, 0x00, 0x00 };

I could verify this with tcpdump (on the module) and with our probe 
(http://www.beckhoff.de/default.asp?ethercat/et2000.htm) over Wireshark.
What do you think about this?

I have another question to use always layer 2 for status frame.
Is this always necessary?
Because I think UDP/IPv4 status frames should also possible.

I could change this for our tests. What do you think about this?

Thanks,
Mario