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Date: Thu, 13 Oct 2011 12:51:51 +0200
From: Gerd Hoffmann <kraxel@redhat.com>
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Subject: Re: [Qemu-devel] [BUG] USB assertion triggers in
	usb_packet_complete()
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To: Thomas Huth <thuth@linux.vnet.ibm.com>
Cc: Stefan Hajnoczi <stefanha@gmail.com>, qemu-devel@nongnu.org

   Hi,

>> Hi Thomas,
>> I hit the same bug recently and Gerd has posted a patch which you can test:
>> http://patchwork.ozlabs.org/patch/118726/
>
> Thanks for the hint, Stefan, you're right, that seems to be the same
> bug. Your patch is working fine in my scenario, too.
>
> However, Gerd's patch is not working for me, the assertion still
> triggers. It seems like usb_packet_complete() is called for the leaf
> node before it is called for the hub node, so the leaf node already set
> p->owner = NULL.

Ah, right, on completion the call chain goes the other way around, so 
the usb_handle_packet() style approach doesn't fly.

I think going with Stefans approach + a big fat comment is the best 
solution then.  I'll go queue up a patch.

cheers,
   Gerd