RE: xhci dmesg flood on short packet

[David Laight]

From: Of Parag Warudkar
> I see a continuous flood of below messages on plugging in/using my USB
> token. (The comp code wasn't in the original message - I added it.) From
> what I can tell the device continues to work as expected.
> 
> Should the warning be disabled for COMP_SHORT_TX like it is for COMP_STOP
> and COMP_STOP_INVAL?
> 
> Parag
> 
> [104692.771649] xhci_hcd 0000:00:14.0: WARN Event TRB comp code 13 for
> slot 2 ep 10 with no TDs queued?

A completion event with nothing queued looks like something horrid.
I'd do some further analysis to find which TRB have been queued and
the completion (or other) events that removed them.

IIRC the COMP_SHORT_TX completion usually means that the received USB packet
is shorter than the buffer (it is really a short RX!).
This is completely normal for many devices.
There is a slight fubar with some host controllers that fail to report
it exactly as per the standard - but that gives a different message.

	David

> [104692.777279] xhci_hcd 0000:00:14.0: WARN Event TRB comp code 13 for
> slot 2 ep 10 with no TDs queued?
> [104692.793894] xhci_hcd 0000:00:14.0: WARN Event TRB comp code 13 for
> slot 2 ep 10 with no TDs queued?
> [104692.813033] xhci_hcd 0000:00:14.0: WARN Event TRB comp code 13 for
> slot 2 ep 10 with no TDs queued?
> [104692.823476] xhci_hcd 0000:00:14.0: WARN Event TRB comp code 13 for
> slot 2 ep 10 with no TDs queued?
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