Hello All,
I have been trying to use ptp4l with a gPTP profile between multiple
devices and an Extreme x440-48t. It works fine with the devices containing
I210 network controllers but it fails on a device using an I219-v network
controller.
The propagation time between the I219-v and the Extreme is around 7.3μs and
therefore does not fall below the default gPTP profile propagation delay
threshold of 800ns. For reference, the propagation time of the I210 is in
the range of 20ns.
If I increase the propagation delay threshold to 10μs on the I219-v and the
Extreme, the device is set AS Capable and syncing happens with a very
inconsistent accuracy of rms 50-150ns and spikes to ~2μs on occasion.
Whereas the I210 has a stable accuracy in the range of 5-10ns. There is no
other traffic on the network.
To me, the propagation delay seems much higher than it should be on the
I219-v since it is directly connected to the switch with a very short
cable. I think the problem is either with the hardware or drivers.
I updated the e1000e drivers for the I219-v to version 3.4.1.1-NAPI with
much difficulty since it seems to require an older kernel than I had and I
had to make changes to the makefile to get it working. I am now using
4.13.0-45-generic kernel. e1000e also requires an e1000 version newer than
7.6.15.5 which I was not able to upgrade to 8.0.35, again due to issues
with the makefile and requiring deprecated kernel headers.
Admittedly this is most likely a driver issue but I would rather not be
downgrading or fiddling with kernel stuff unless I have to.
So I am just wondering if anyone has experienced similar issues with the
I219-v or the e1000/e1000e drivers?
Is the 7μs really as unreasonable as I think?
Any recommendations on how to proceed?
Is increasing the propagation delay threshold a suitable fix?
Thank you,
Andre.
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