On Tue, Jul 29, 2014 at 05:53:59AM -0400, Greg Troxel wrote: > >> Also, note in the ucom(4) man page that there is about 1 ms of > >> latency. Discussed on tech-kern in October of 2013, with the only > >> concern being that someone who didn't know what they were doing might > >> set up a stratum 1 server, and that somehow might have worse > >> timekeeping than whatever else that person might have done; the man > >> page comment is a mitigation for this. > > > > latency of 1ms and the same jitter - only ucycom uses interrupt > > endpoints for data transfer > > I was abstracting on purpose, because no other man page describes > performance characteristics in such detail. (When I tested, my best > guess was that the delay from PPS edge capture ranged from 400us to > 1400us as the USB frame clock shifted.)
In few other cases does it matter at this level either... -- David A. Holland dholl...@netbsd.org
