[CentOS] Experiencing continual eth0 link up/down on a 10G Chelsio NIC (cxgb3 driver)

Mon Feb 8 18:43:53 UTC 2010
Arun Khan <knura9 at gmail.com>

File Server OS: CentOS 5.3 (x86_64)
Kernel: CentOS  Plus kernel (need XFS fs drivers)

The file server has a Chelsio T310 10GBASE-CX4 RNIC (rev 3) PCI
Express x8 MSI-X (eth0), driver and firmware is stock from the CentOS
Plus kernel.

Using ethtool  I have verified driver association with the 3 NICs on
the system (eth1 and eth2 are not connected to any switch)

Driver for eth0
driver: cxgb3
version: 1.1.3-ko
firmware-version: T 7.4.0 TP 1.1.0

Driver for eth1
driver: e1000e
version: 1.0.2-k2
firmware-version: 1.0-0

Driver for eth2
driver: e1000e
version: 1.0.2-k2
firmware-version: 1.0-0


The last 3-4 weeks, I have noticed that the eth0 link keeps going up
and down, confirmed by "dmesg" output as well in /var/log/messages
(dmesg sample shown below).

eth0: link down
eth0: link up, 10Gbps, full-duplex
eth0: link down
eth0: link up, 10Gbps, full-duplex
eth0: link down
eth0: link up, 10Gbps, full-duplex

The kernel RPM verification shows no errors

# uname --kernel-release
2.6.18-164.2.1.el5.plus

# rpm --verify kernel-2.6.18-164.2.1.el5.plus

The hardware vendor tells me that the card either fails completely
(kaput) or works - there is no grey area.  He is of the opinion that
the problem is with the driver.

Verification of the kernel rpm tells me that all files including the
cxgb3 driver file md5sum are OK.

I would like to hear from anyone with the same NIC or another rev.
using the same driver.
    Are you seeing similar link up/down in your system?
    How did you solve the problem?

TIA
-- Arun Khan