To answer my own question: it appears that USB peripherals return NAKs not only when the peripheral is not ready to accept the data, but also when the peripheral doesn't know what to do with the data. So an infinite series of NAKs basically is just the device's way of saying: I don't know what the heck to do with the data you keep sending me. I expected to get an error result for such a case, but I can see why sending a NAK may be the most natural response for the device. Anyhow, hopefully this will be helpful for others in the future (perhaps it's obvious, but it wasn't to me... ;-). --david On Fri, Mar 7, 2014 at 6:16 PM, David Mosberger <davidm@xxxxxxxxxx> wrote: > So the MAX3421E driver is working quite well but one problem I'm > seeing is that after running devices for a while, they seem to get > into a mode where a bulk out transfer gets stuck soliciting and > endless stream of NAKs. The MAX3421E retries NAK'd transfers in the > next frame again, only to get the same response, forever. I see this > both with a mass storage device and a WIFI adapter (which is > specifically advertised as being USB 1.1 compatible). Anybody have > any ideas where that might be coming from? > > --david > -- > eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768 -- eGauge Systems LLC, http://egauge.net/, 1.877-EGAUGE1, fax 720.545.9768 -- 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
