Intel IXGBE 3.23.2 Driver: "DCA registration failed" in dmesg - IBM Server

Resolving The Problem

Source

RETAIN tip: H006784

Symptom

The Intel X540-T2 Dual-Port 10GBase-T Adapter for IBM System x installed in any Linux operating system has the following the message in dmesg:

(where DCA = Direct Cache Access)

Affected configurations

The system is configured with one or more of the following IBM Option part numbers:

• Intel X540-T2 Dual-Port 10 GBaseT Ethernet Adapter, Option part number 49Y7970, any replacement part number

This tip is not system specific.

This tip is not software specific.

The Intel ixgbe device driver for the Intel 10 Gb adapters is affected.

The system has the symptom described above.

Solution

This behavior will be corrected in a future release of Intel SW CD.

The target date for this release is scheduled for first quarter 2016.

The file is or will be available by selecting the appropriate Product Group, type of System, Product name, Product machine type, and operating system on IBM Support's Fix Central web page, at the following URL:     http://www.ibm.com/support/fixcentral/

Workaround

The in-box Linux driver does not have this issue.

Additional information

The DCA stands for Direct Cache Access, if the driver is enabled for DCA this parameter allows load-time control of the feature. The message is a result of DCA not being enabled correctly. However, Intel has never seen measurable performance increase from DCA, though it theoretically can help in cases with multiple flows with small packets.

This issue will be fixed with an updated ixgbe driver.