B.Vinai Kumar wrote: > I Have a device controller with Control, Bulk, Interrupt endpoints, it > does not have > ISOCH endpoint. Can I stream the USB Audio over bulk endpoint. Bulk data transfers have an unpredictable latency because of the error handling and because other transfers might interfere, so you need a quite large buffer in the device, which increase latency. Furthermore, you cannot reserve bandwidth for bulk transfers, so there is no guarantee that any particular buffer size is actually sufficient. There are many cheap USB controllers with iso support available, so doing audio over bulk is a bad idea. (Being a bad idea, however, guarantees that somebody does it; in this case, it's the M2Tech hiFace.) > If we can, then the existing usb audio class drivers will work with > this kind of device. No. > If I connect a usb 2.0 webcam(high speed High badwidth isoch endpoint) > under usb 2.0 Hub, > Does it will affect the usb audio performance. (it's between Periodic > vs Asynchronous scheduler) Iso bandwidth, when reserved, is guaranteed to be available; bulk is not. Using the webcam might kill your bulk audio output. Regards, Clemens -- 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
