MLewis via devel writes: > "Strictly speaking, the PPS pulse isn�t even necessary for this process. > One could > simply generate a pulse on the external interrupt line once per second at a > known > time. "
Yes, and if you use both measurements to eliminate the interrupt latency, then random error propagation (assuming jitter is not correlated between input and output) ensures that your measurement error goes up by a factor of sqrt(2). So you're better of just ignoring the PPS kernel timestamp even from a theoretical standpoint. > I'm currently using REALTIME_CLOCK. There's also the thread clock and > the cpu clock. Principally it should be better to use an unslewed clock source (one of the hardware timers). That's what the RADclock was all about, but the API sadly never went into the mainline kernel. But without a proper API these are tricky to use portably and you're left with various interference from e.g. power saving. Regards, Achim. -- +<[Q+ Matrix-12 WAVE#46+305 Neuron microQkb Andromeda XTk Blofeld]>+ SD adaptation for Waldorf rackAttack V1.04R1: http://Synth.Stromeko.net/Downloads.html#WaldorfSDada _______________________________________________ devel mailing list devel@ntpsec.org http://lists.ntpsec.org/mailman/listinfo/devel