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Subject: Re: [bug, bisected] pfifo_fast causes packet reordering
To:     Paolo Abeni <pabeni@redhat.com>,
        John Fastabend <john.fastabend@gmail.com>,
        Dave Taht <dave.taht@gmail.com>
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        "David S. Miller" <davem@davemloft.net>,
        "linux-can@vger.kernel.org" <linux-can@vger.kernel.org>,
        Martin Elshuber <martin.elshuber@theobroma-systems.com>
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From:   Jakob Unterwurzacher <jakob.unterwurzacher@theobroma-systems.com>
Message-ID: <5468f8eb-17b6-9000-ab4d-a2c67ef35e4b@theobroma-systems.com>
Date:   Mon, 19 Mar 2018 13:56:47 +0100
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On 19.03.18 13:32, Paolo Abeni wrote:
> Is not clear to me if you can reproduce the bug with the vanilla
> kernel, or if  you need some out-of-tree nic driver. Can you please
> clarify which NIC/driver are you using?

Yes I reproduced it with a vanilla kernel. I use two off-the-shelf USB 
NICs, lsusb says:

   Bus 005 Device 013: ID 0b95:7720 ASIX Electronics Corp. AX88772
   Bus 005 Device 014: ID 0b95:772b ASIX Electronics Corp. AX88772B

Photo of the setup:
https://github.com/jakob-tsd/pfifo_stress/blob/master/usb_nics.jpg

Best regards,
Jakob