SATA port multiplier support ready yet?

[Dieter]

> They are only supported at the moment by controllers that are
> intelligent enough to hide the details of how they work from
> the OS. The SiI family probably doesn't fall into this category.
> I'm working on this as part of a larger SATA/SAS/SCSI/FC overhaul,
> but it'll be a few months before there are any results.

It has been a few months, any news on port multiplier support?

If not, how does this "intelligent enough to hide the details" stuff
work?  Does the controller lie to the OS and say "I have 6 ports"
rather than "I have 2 ports" and then the device says "I'm a 5:1
portmultiplier"?

Is there a magic string one can search for to find these intelligent
controllers?