From: 	Andrew Vasquez <andrew.vasquez@qlogic.com>

RIO mode 3 (originally used in the qla2xxx driver) will not work on
big-endian platforms due to the firmware returning only the first-word
of the dword command handle returned after SCSI completion.  Use RIO
mode 4 since full 32bit handle is returned during status.

I've recently added an IBM p630 machine (ppc64) to my test ring with a
mix of 2200 and 2300 cards -- I feel fairly confident that most endian
type issues are addressed.