Subject: Re: [bisected regression] e1000e: "Detected Hardware Unit Hang"

From: Thomas Jarosch <[email-masked]>
Date: Fri, 13 Feb 2015 17:14:55 +0100

Hi Aaron,

On Thursday, 12. February 2015 23:28:27 Brown, Aaron F wrote:
> I do not have any real info.  I had been asked to try and reproduce some
> unit hangs (maybe for this) recently and did not succeed in producing
> them on the parts I have.  Reading through the thread I see this is
> showing up in a NAT environment.  The port that is getting the unit hang
> in the NAT system?

yes, the e1000e NIC is serving the NATed Windows client.

The setup was outlined here:

    http://marc.info/?l=linux-netdev&m=142133691713824&w=2

> I will make some attempts at replicating this with the port in a NAT and
> or forwarding role.  Has a bug been opened for this?  Or has information
> for this specific unit hang been entered into one of the other unit hang
> bugs opened against e1000e?

I didn't do anything(tm). This report sounds like the same issue:

    http://ehc.ac/p/e1000/bugs/378/

Oliver Wagner wrote the problem started to appear
after updating from kernel 3.5 to 3.8.0.35 (new frag size code).

I just noticed now he wrote he has two identical boxes:

---------------------------------------------------
- Box with symptoms: Router/Firewall, packet forwarding
  between different VLANs on eth0 and eth1
- Box without symptoms: Fileserver, eth0/eth1 bonded
  (VLANs used, but no forwarding)
---------------------------------------------------

So it looks like it's related to forwarding somehow,
I've made the same experience IIRC.

Cheers,
Thomas