On Thursday 13 March 2014 18:15:06 David Mosberger did opine: > 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 I just ran into something very similar David. I have an Epson MFD, printer/scanner which has been turned off because the print head packed up when it was still new, but I kept it for the scanner. Turned off. Asked to scan something and email it by the better half, I turned it on, but unbeknownst to me, something had send about 50 some jobs to it so they were sitting in the queue, feed all the paper still in it on thru as blank, then went into an infinite loop of asking for more paper, and it could not be canceled as the keyboard had been seized, and mouse click any place but on those requesters were acknowledged but ignored. Nothing to do but hit the rest button on the tower. On reboot, I was able to access it and clean out the queue with a browser, then turned it on and did my scanning, twice now with no further problems. I'd squawk at Michael Sweet (cups) but that mailing list went dead after he sold himself and cups to Apple, so there is not now a feedback path that I can find for us peons to use. I knew Michael from school days, long before he ever started cups. Perhaps its time for a cups fork? > 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 Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> -- 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
