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SubjectRe: USB autosuspend vs. URB submission
On Thursday 10 January 2013 00:05:55 Laurent Pinchart wrote:

> I've had a quick look at the trace posted at
> but usbmon only shows URBs
> that are successfully submitted. I'm not sure what useful information I could
> get from the trace.

The test is at the very start of usb_submit_urb()

if (!urb || !urb->complete)
return -EINVAL;
if (urb->hcpriv) {
WARN_ONCE(1, "URB %p submitted while active\n", urb);
return -EBUSY;

usbmon will never see such URBs

I suggest that for debugging you change the WARN_ONCE into a WARN and compare
the URB pointers of usbmon and dmesg.

In the long run it is probably a good idea to pass duplicated URBs to usbmon by
a special code path.


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