Re: USB autosuspend vs. URB submission

[Oliver Neukum]

On Thursday 10 January 2013 00:05:55 Laurent Pinchart wrote:

> I've had a quick look at the trace posted at 
> https://bugzilla.redhat.com/show_bug.cgi?id=879462 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.

	Regards
		Oliver

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