On Thu, May 28, 2015 at 03:01:19PM +0200, Richard Cochran wrote: > On Thu, May 28, 2015 at 08:24:59AM +0200, Miroslav Lichvar wrote: > > Hm, so the offset normally stays at zero or is it stepping on each > > update? > > It always stays zero. Non-zero offsets only appear in error > conditions, like resetting the GM's time or breaking the SyncE chain.
Interesting. Is the measured offset zero because it's a feature of the SyncE design, or is it just so small that it's not visible in the 1ns resolution? > > In seems odd to me to call the servo function and then ignore its > > result. In general this breaks the internal state of the servo since > > the assumption is that it is always controlling the clock. > > But a new servo type would make sense to you? I think it would. It could be a "dumb" servo that would step any offset and return with locked state when the offset is below the value set by the step_threshold option. Or it could be a simple P controller, which would by design return zero frequency offset when the phase offset is zero. Or the current PI servo could be extended to support zero I constant. -- Miroslav Lichvar ------------------------------------------------------------------------------ _______________________________________________ Linuxptp-devel mailing list Linuxptp-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linuxptp-devel
