[Acked/cmt] [SRU][Trusty][PATCH 0/2] fix "hw csum failure" errors

[Andy Whitcroft]

On Thu, Jan 15, 2015 at 06:04:06PM -0800, Jay Vosburgh wrote:
> 
> BugLink: https://bugs.launchpad.net/bugs/1409123
> 
> SRU Justification
> 
> Impact: Certain network topologies using VXLAN with certain network
> cards will experience "hw csum failure" errors in the kernel log
> 
> 	"Certain network toplogies" is VXLAN tunneled network between
> two containers or VMs on separate hosts.
> 
> 	"Certain network cards" are at least enic and sky2.  This
> probably includes any other device that performs CHECKSUM_COMPLETE
> receive checksum offload.
> 
> Fix: backport the following two commits from current net-next

Actually these are both in mainline now, as of v3.19-rc3.

> commit 17e96834fd35997ca7cdfbf15413bcd5a36ad448
> Author: Govindarajulu Varadarajan <_govind at gmx.com>
> Date:   Thu Dec 18 15:58:42 2014 +0530
> 
>     enic: fix rx skb checksum
> 
> commit 2c26d34bbcc0b3f30385d5587aa232289e2eed8e
> Author: Jay Vosburgh <jay.vosburgh at canonical.com>
> Date:   Fri Dec 19 15:32:00 2014 -0800
> 
>     net/core: Handle csum for CHECKSUM_COMPLETE VXLAN forwarding

Both seems to be trivial backports from those originals, and as such
seem acceptable.  Depending on the severity of the symtoms, it is not
clear to me if these are just annoying traces or data is being lost at
the same time, we could take these in advance of them going to -stable.
Also these probabally should go to -stable :).  I think davem handles
this differently to everyone else of course, so they may be in plan for
-stable already.

Overall:

Acked-by: Andy Whitcroft <apw at canonical.com>

-apw