I'm wondering what changes would ptp4l need in the kernel in order to support operation with bonded interfaces as a PTP slave. Currently, as I understand it, it doesn't work at all, at least with the UDP transports. I'm not very familiar with the kernel code, please tell me if what I say doesn't make any sense.
I think there are at least two possible approaches. One would be to add support for timestamping on the master interface and the kernel would send to sockets bound to the interface timestamps from interfaces that are currently active. As each slave interface may have its own clock, ptp4l would need to know from which interface the timestamp is. When that source changes, ptp4l would need to update its state and restart the servo. phc2sys would need to know about all interfaces and select the one which is currently synchronized. A simpler approach (at least on the ptp4l side) would be to allow receiving and sending multicast packets on sockets bound to the slave interfaces. For each slave interface there would be a separate ptp4l instance running which would synchronize the clock when the interface is active and is actually receiving/sending packets. For each ptp4l there would be a phc2sys instance writing measurements to SHM or phc2sys could be improved to support multiple ptp4l sources. Would this require more than a new socket option in the kernel? FWIW, in a test I did with a single bonded interface and the L2 transport ptp4l was able to bind to the slave interface, send and receive packets, and synchronize the clock. I didn't have a chance to try it with multiple interfaces and other bonding modes. Does anyone know if it would work? Thoughts? -- Miroslav Lichvar ------------------------------------------------------------------------------ Transform Data into Opportunity. Accelerate data analysis in your applications with Intel Data Analytics Acceleration Library. Click to learn more. http://pubads.g.doubleclick.net/gampad/clk?id=278785231&iu=/4140 _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
