Mark Nelson writes:
 > On Sat, Aug 23, 2008 at 8:01 AM, Mikael Pettersson [off-list ref] wrote:
 > > Jeff Garzik writes:
 > >  > Mikael Pettersson wrote:
 > >  > > Mark Nelson writes:
 > >  > >  > > But without docs or a reference driver I cannot really say what it
 > >  > >  > > would take to support it, sorry.
 > >  > >  >
 > >  > >  > Yeah, I figured as much after reading that hardware docs
 > >  > >  > are only available under NDA... I do have Promise's "partial
 > >  > >  > open source driver" all working with the controller; but I
 > >  > >  > don't think that's what you meant by reference driver, is it?
 > >  > >
 > >  > > No. Promise's partial-source drivers sometimes contain some useful
 > >  > > information, like register definitions, but the only useful info
 > >  > > in the TX4650 driver is the PCI ID list for the T3 chip family.
 > >  >
 > >  > FWIW there's always the chance it belongs to drivers/scsi/stex.c...
 > >
 > > True, but unfortunately I doubt it as the PCI IDs in the tx4650
 > > (partial) sources bear no resemblance to the ones in stex.c.
 > 
 > Would the other PCI IDs that are found in the tx4650 driver give any
 > clue as to which other chips the T3 controller is similar to (or does
 > that just show that Promise likes to reuse the open source wrapper
 > around their binary blob)?

The latter. The tx4650 sources lists chips from Intel (AHCI), ATI, and
Marvell, and they are definitely dissimilar to Promise's own chips.

 > Forgive my ignorance, but does the fact that the T3 controller can also
 > use SAS disks mean we should be looking for a SCSI driver?

Promise lists only this one partial-source driver for the tx4650,
and it /is/ a Linux scsi driver.