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Bad UDP checksum with 82540EM

To: cramerj@xxxxxxxxx
Subject: Bad UDP checksum with 82540EM
From: Andreas Schwab <schwab@xxxxxxx>
Date: Sat, 07 Feb 2004 14:35:45 +0100
Cc: netdev@xxxxxxxxxxx
Sender: netdev-bounce@xxxxxxxxxxx
User-agent: Gnus/5.1006 (Gnus v5.10.6) Emacs/21.3.50 (gnu/linux)
I'm getting bad UPD checksums in outgoing packets with the e1000 driver
(version 5.2.16) in 2.6.1 when using HW checksumming on a HP branded
82540EM on ia64 (TCP works fine).  The same driver works fine with an
Intel branded chip.  The two devices are identified as follows:

  Model: "Hewlett-Packard Company 82540EM Gigabit Ethernet Controller"
  Vendor: pci 0x8086 "Intel Corporation"
  Device: pci 0x100e "82540EM Gigabit Ethernet Controller"
  SubVendor: pci 0x103c "Hewlett-Packard Company"
  SubDevice: pci 0x1274 

  Model: "Intel 82540EM Gigabit Ethernet Controller"
  Vendor: pci 0x8086 "Intel Corporation"
  Device: pci 0x100e "82540EM Gigabit Ethernet Controller"
  SubVendor: pci 0x8086 "Intel Corporation"
  SubDevice: pci 0x3402 

After disabling tx-checksumming UDP is working again.

Andreas.

-- 
Andreas Schwab, SuSE Labs, schwab@xxxxxxx
SuSE Linux AG, Maxfeldstraße 5, 90409 Nürnberg, Germany
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