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From: Oliver Neukum <oneukum@suse.de>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Josh Boyer <jwboyer@redhat.com>,
	Alan Stern <stern@rowland.harvard.edu>,
	gregkh@linuxfoundation.org, mdharm-usb@one-eyed-alien.net,
	linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: USB autosuspend vs. URB submission
Date: Thu, 10 Jan 2013 10:42:37 +0100	[thread overview]
Message-ID: <1643419.R9VmOAX4j3@linux-5eaq.site> (raw)
In-Reply-To: <2664900.viczl5BYBS@avalon>

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


  parent reply	other threads:[~2013-01-10  9:42 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-01-07 20:42 USB autosuspend vs. URB submission Josh Boyer
2013-01-08 15:51 ` Alan Stern
2013-01-08 16:03   ` Josh Boyer
2013-01-09 23:05     ` Laurent Pinchart
2013-01-10  5:13       ` Ming Lei
2013-01-10 10:02         ` Oliver Neukum
2013-01-10  9:42       ` Oliver Neukum [this message]
2013-01-10 15:20         ` Alan Stern
2013-01-10 15:37           ` Oliver Neukum
2013-01-10 15:13       ` Alan Stern

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