08.02.2015 17:35, Georg Chini wrote: > >>> I think there is some misunderstanding. Let me repeat in a different >>> way. >>> >>> The smoother works perfectly (both for timer-based scheduling and for >>> the needs of your module) on non-batch cards. >>> >>> But, even for batch cards, where timer-based scheduling is disabled, >>> the smoother is active and is actually used for reporting the latency >>> to your module. An attempt to use the smoother for timer-based >>> scheduling on batch cards has failed. That's why I suspect that it, >>> on batch cards, also tells lies to your module. >> >> OK, understood. I don't have anything to test it though > > Mh, are my USB devices batch cards? I just noticed it says "Disabling > timer scheduling > because BATCH flag is set" in the log and I am not sure, what a batch > card is. Yes, your USB devices are batch cards. This means that they don't report their playback position accurately enough. For USB devices, the granularity of position reports is 6 ms (for large period sizes), but for others, it may be up to one period size. -- Alexander E. Patrakov