I've attached a patch to version 3.4.14-115. It supports a kernel parameter, "hpsa.ignore=1,2" for example, to ignore the drives in bays 1 and 2.
I am interested in functionality similar to what is provided via kernel parameter by the "libata" driver that allows a disk to be ignored with "libata.force=X:00:disable". I currently have minor mods to the hpsa driver to accept a parameter and set the "expose_device" field when in HBA mode. Unlike RAID mode with logical devices the driver mostly stays out of the way in HBA mode so the effort seems minimal. In general the physical disks are discovered on each "scan" but "hpsa" opts out of motifying...