Re: [Linuxptp-users] PTP through a bridge interface

[Rob C. <RCo...@si...>]

Hi Jake, appreciate the reply -

But just for my feasibility testing purposes if I:
--Pass eth0 (imx6 mac connected to cpu port of dsa switch) to ptp4l so it can create the clock and enable timestamping etc, and
--In my patch just bind the udp socket to 'br0' instead of 'eth0'  (and join mcast group on 'br0')
Doesn't this suffice to allow recving traffic over a bridge interface?

Thanks,
Rob

-----Original Message-----
From: Keller, Jacob E <jac...@in...> 
Sent: Tuesday, June 5, 2018 11:21 AM
To: Rob Cornall <RCo...@si...>; Richard Cochran <ric...@gm...>
Cc: lin...@li...
Subject: RE: [Linuxptp-users] PTP through a bridge interface



> -----Original Message-----
> From: Rob Cornall [mailto:RCo...@si...]
> Sent: Tuesday, June 05, 2018 9:47 AM
> To: Richard Cochran <ric...@gm...>
> Cc: lin...@li...
> Subject: Re: [Linuxptp-users] PTP through a bridge interface
> 
> Hi Richard, I really appreciate you answering my questions so quickly.
> 
> I attached my logs where I ran a patched version of ptp4l on the GM 
> device (I also attached this patch), the patch simply binds the socket 
> to br0 and joins the multicast group on the br0 interface instead of 
> the eth0 interface supplied In the command.
> Our routes go through br0 as expected in this situation:
> 
> $ ip ro.3
> 224.0.0.0/4 dev br0  scope link
> ...
> 
> And our DSA is setup as a 'dumb' switch, all unknown DA frames are 
> flooded out all ports.
> 
> Also our particular marvell switch does not have the ptp support, we 
> are aware that some versions do.
> 
> When seeing the slave adjusting its ptp clock this leads me to think 
> everything works okay with this patch? Is this something that could be 
> added as an option to ptp4l and merged in the future to support linux sw bridges?
> 
> Thanks,
> Rob

I think you really want the bridge to learn that it's underlying devices have PTP hardware support, and then connect them in a sort of JBOD like setup. I don't have any idea how hard that would be to do.

Thanks,
Jake