HBA failing with message: "LOOP DOWN detected (2)"

Issue

• HBA failing intermittently. Errors seen in logs are below:

Aug 27 09:07:47 hostname kernel: qla2400 0000:24:00.0: LOOP UP detected (4 Gbps).
Aug 27 09:07:48 hostname kernel: qla2400 0000:24:00.0: SNS scan failed -- assuming zero-entry result...
Aug 27 09:17:09 hostname kernel: qla2400 0000:24:00.0: LOOP DOWN detected (2).
[/snip]
Aug 27 09:17:44 hostname kernel: qla2400 0000:24:00.0: LOOP UP detected (4 Gbps).
Aug 27 09:17:45 hostname kernel: qla2400 0000:24:00.0: SNS scan failed -- assuming zero-entry result...
Aug 27 09:19:17 hostname kernel: qla2400 0000:24:00.0: LOOP DOWN detected (2).

• Note that the HBA will come up and then about some time later it will go down.