Re: [PATCH v2 3/3] xhci: Manually give back cancelled URB if queuing it for cancel fails

[Felipe Balbi <felipe.balbi@linux.intel.com>]

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Felipe Balbi <felipe.balbi@linux.intel.com> writes:

> Hi,
>
> Mathias Nyman <mathias.nyman@linux.intel.com> writes:
>> Manually give back URB if we are can not add it to the cancel queue, and
>> stop the endpoint normally.
>
> this sentence doesn't parse very well ;-)
>
>> This can happen if device just reset before URB timed out and dequeued,
>> leading to missing endpoint ring.
>
> seems like this could be extended a bit too.
>
>> @@ -1554,6 +1553,14 @@ int xhci_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
>>  done:
>>  	spin_unlock_irqrestore(&xhci->lock, flags);
>>  	return ret;
>> +
>> +err_giveback:
>> +	if (urb_priv)
>> +		xhci_urb_free_priv(urb_priv);
>> +	usb_hcd_unlink_urb_from_ep(hcd, urb);
>
> well, aren't you introducing another regression here?
>
> if the return status from usb_hcd_check_unlink_urb() is -EBUSY, then,
> perhaps, you really shouldn't give it back now.

not to mention the following excerpt from usb_hcd_check_unlink_urb()
kdoc:

 * Return: 0 for no error, otherwise a negative error code (in which case
 * the dequeue() method must fail).  The possible error codes are:
 *
 *	-EIDRM: @urb was not submitted or has already completed.
 *		The completion function may not have been called yet.
 *
 *	-EBUSY: @urb has already been unlinked.

-- 
balbi

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