Re: Bad UDP checksum with 82540EM

[Andi Kleen <ak@xxxxxxx>]

On Sat, 07 Feb 2004 23:42:21 +0100
Andreas Schwab <schwab@xxxxxxx> wrote:

> Jon D Mason <jonmason@xxxxxxxxxx> writes:
> 
> > This probably isn't helpful, but it sounds like a hardware error.  Is the 
> > error occurring on multiple/all HP adapters, or only one? 
> 
> I've also seen it with a HP branded BCM5701 on IA64, but also with a
> Broadcom BCM5702 on AMD64 (both using the tg3 driver).  It seems like
> broken UDP checksumming is rather common. :-(

It could be still a software bug.  When hardware checksumming is available
the UDP packets use a slightly different path through the stack.

Could you perhaps test if the problem occurs in a 32bit box with the 
same NIC ? Maybe it is some 64bit problem somewhere in software.

-Andi