[PATCH] r8152: stop submitting rx for -EPROTO

Hayes Wang hayeswang at realtek.com
Thu Sep 30 20:26:48 PDT 2021


> Alan Stern <stern at rowland.harvard.edu>
> [...]
> > There has been some discussion about this in the past.
> >
> > In general, -EPROTO is almost always a non-recoverable error.
> 
> Excuse me. I am confused about the above description.
> I got -EPROTO before, when I debugged another issue.
> However, the bulk transfer still worked after I resubmitted
> the transfer. I didn't do anything to recover it. That is why
> I do resubmission for -EPROTO.

I check the Linux driver and the xHCI spec.
The driver gets -EPROTO for bulk transfer, when the host
returns COMP_USB_TRANSACTION_ERROR.
According to the spec of xHCI, USB TRANSACTION ERROR
means the host did not receive a valid response from the
device (Timeout, CRC, Bad PID, unexpected NYET, etc.).
It seems to be reasonable why resubmission sometimes works.

Best Regards,
Hayes





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