> From: Nick Hudson [mailto:skrll@xxxxxxxxxx] > Sent: Tuesday, July 22, 2014 12:19 AM > > On 09/23/13 22:23, Paul Zimmerman wrote: > > Here is the third version of the microframe scheduler patch. This > > version removes the NAK holdoff patch from the series, since it > > was effectively a no-op as pointed out by Matthijs. > > I think there was a misunderstanding here - Matthijs was pointing out that the > next_sched_frame variable was unused. That particular variable is part of the > downstream Pi driver's FIQ code. Right, but without that, the patch didn't actually do anything as far as I could see. > The nak_frame handling would have added some benefit, but wouldn't handle all > cases. > > I'm seeing problems with devices NAKing to the point of confusing dwc2 completely, > so I'd like to investigate a NAK holdoff scheme that's acceptable for dwc2. I > suspect the best thing to do here is to add a nak_count field to dwc2_qh (or maybe > dwc2_qtd) and increment in dwc2_hc_nak_intr. If the count exceeds a threshold > then it would call > > dwc2_halt_channel(hsotg, chan, qtd, DWC2_HC_XFER_NAK); > > and go around again. > > I assume the NAK count would need resetting everywhere qtd->error_count is reset. > > How does this sound? Sounds good to me. BTW, can you give me a pointer to one of the devices that gives excessive NAKs? I would like to buy one for the lab here to test with. -- Paul -- 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
