On Sat, 13 Jul 2013, Clemens Ladisch wrote: > James Stone wrote: > > On Mon, Jul 8, 2013 at 2:12 PM, James Stone <jamesmstone@xxxxxxxxx> wrote: > >>> configuring for 44100Hz, period = 64 frames (1.5 ms), buffer = 2 periods > >>> JackAudioDriver::ProcessAsync: read error, stopping... > >> > >> Some further info - on 3.5.0-28, I can start jackd in playback only > >> with 8 frames/period, and capture only at 16 frames/period. > > > > Any thoughts on further investigating this bug with the 3.8.0 kernel > > with the Focusrite Scarlett 2i4? > > Jack assumes that the interrupts for the playback and capture streams > happen at more or less the same time. It might be possible that on the > newer kernels, there is a difference between the arrival times of the > first completion callback of each stream. The interrupts shouldn't differ by more than the duration of one URB, which would be 1 ms. There is an initial delay when a stream is first started, which generally lasts 5-10 ms. But I think that hasn't changed since the 3.5 kernel. Would it make any difference? I could write a patch to reduce or eliminate it. Bear in mind that the input and output streams are started at totally different times. There's no reason to expect the first completion interrupts to be close together. And anyway, James's latest problem occurs even with playback only. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
