How does ALSA handle errors in isochronous USB data USB transfers fixed data rate digital audio data using its _isochronous_ mode. To ensure the fixed data rate, this mode has no provision for retries of faulty transmissions. How does ALSA handle reception of isochronous data packets that have detectable data transmission errors (such as a CRC error)? Does it pass the data through as-is, doing a best effort? That would result typically result in some bits of PCM audio being in error. Or does it replace the faulty data with a sequence of zero values? Or something else?

Isochronous packets with CRC errors are dropped by the USB controller hardware; the software does not see them.

Capturing just continues with the following samples. There is likely to be a discontinuity in the waveform.