link failures reported with errors : "kernel: lpfc 0000:04:00.2: 0:(0):0915 Register VPI failed : Status: x20 upd bit: x0"

Issue

• After a Clear Virtual Link Event occurred, re-registering the physical port VPI failed with a status code of 0x20

 kernel: lpfc 0000:04:00.2: 0:2718 Clear Virtual Link Received for VPI 0x0 tag 0x2
 kernel: lpfc 0000:04:00.2: 0:2546 New FCF event, evt_tag:x3, index:x0
 kernel: lpfc 0000:04:00.2: 0:(0):0915 Register VPI failed : Status: x20 upd bit: x0
 kernel: lpfc 0000:04:00.2: 0:(0):0915 Register VPI failed : Status: x20 upd bit: x0

• The only way we have found to resolve this link failure is a reboot.