Ethercat random jitter fix

Posting here with some pictures and any stylization is hell, trust me ...

it looks pretty ... reduction of any jitter in the rt system is more than welcome ... pll is very critical stuff for system and it is nice to see its major improvement 

Which driver for network card are you usig for testing it for now? jittering can be produce by generic drivers too i think

I saw it was merged in the master ... we will wait for scott to public new feed or version? 

I use Intel I225 with ec_igc driver, but I also tested generic and seems ok, I plan to do more extensive testing on something worse, just to see how bad I can go before I hit any issue, to have an idea on how cheap a system I can make lol.

The newest PR has not been merged yet at this time, you can get the code from my repo, or wait a few weeks for Scott, he mentioned he was going out of town.

I really think now the code respects the ethercat standard as closely as possible, it might just be a matter of exposing some phasing paramets for picky applications, but visualiziotion with halscope and sync0shift gets you all the way there too, and you have two options to choose from syncToRefClock true or false, if your latency is decent I advise to keep it false, with a refClockSyncCycles of 2, or 10 if you can wait a bit before start moving.

I have been using negative ref cycles setup ... everything works well, but I have been using native drivers with custom configuration ... latency is very low in my case

it is here ? github.com/grandixximo/linuxcnc-ethercat