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.

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?

Nick

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