<html><head></head><body><div style="font-family: Verdana;font-size: 12.0px;"><div>Hello,</div>
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<div>I successfully got the IgH EtherCAT Master running on an IEI board using Gentoo and the 4.14.28-rt23 PREEMPT kernel.</div>
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<div>Now, I switched to a self-made, yocto-based distribution, using the same kernel (I tried both the kernel built by our yocto recipe and my own "hand-built" kernel with the exact same result) and now I have a very strange problem:</div>
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<div>The call to ecrt_domain_queue takes sometimes very long (about 10 ms, I measured that call separately). During normal operation it takes no considerable amount of time but while the system is coming up (switching to OP etc.) or if I disconnect a cable it starts taking those large amounts of time. Then of course a 1 ms cycle time fails catastrophic.</div>
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<div>On my gentoo based system, this behaviour does not occur. It never takes too much time, even if I disconnect a cable or reboot a slave. </div>
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<div>As it does not seem to be kernel related, what else could it be? GCC versions differ of course, yocto using 7.2.0 while gentoo is on 6.4.0.</div>
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<div>I narrowed down the issue to the ec_user_example already.</div>
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<div>Cyclictest shows no <a href="http://www.dict.cc/englisch-deutsch/abnormality.html">abnormality</a>, max latency is < 25 us on both systems. I run the system with isolcpus=3 (and smp_affinity=7 for irq) and the cyclictest/ec test program with taskset 8 on the isolated core. So I rule out a generic latency issue.</div>
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<div>I am really a bit puzzled where to start debugging this strange issue and are happy for any hint!</div>
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<div>Thanks a lot,</div>
<div>Michael</div></div></body></html>