OK so after some more digging :
The system can put the USB into suspend/low power mode if it thinks that nothing is connected to it. So this is possibly connected to the read/64, error -110 error message though as that message appears over six seconds later this still begs the question(s)
“What is the initial cause ?” -
Where is the decision made to put the USB hub into low power made ?
Where in the code could the issue be seen first ?
So far half the remedies, that I have seen, for read/64, error -110 are to power down the board and disconnect the devices for a few minutes. Not really practical where everything in connected to tracks on a board, and I don’t know why solution should work.
The other half center on filters, shorter cables and using powered hubs which all tally with power/voltage drop issues.
At the moment I am still trying to rule out software/config issues.
Again, any hints on where in the code to look gratefully received(and may to stop my ramblings).