Re: Playing with SATA NCQ

[Erik Slagter <erik@slagter.name>]

On Sun, 2005-05-29 at 12:34 -0400, Jeff Garzik wrote:
> >>Now, this patch is not complete. It should work and work well, but error
> >>handling isn't really tested or finished yet (by any stretch of the
> >>imagination). So don't use this on a production machine, it _should_ be
> >>safe to use on your test boxes and for-fun workstations though (I run it
> >>here...). I have tested on ich6 and ich7 generation ahci, and with
> >>Maxtor and Seagate drives.
> > Is this supposed to work on ICH7 in legacy mode as well?
> Nope.  ata_piix does not support NCQ (because the h/w doesn't support).

If I understand this correctly: NCQ does not work on ICH7 in native mode
(using ata_piix) because in this mode there is no NCQ available, right?

> > Another question: is there a fundamental problem to have the ICH6/7
> > enabled AHCI mode by the kernel instead of the BIOS? I know some BIOSes
> > don't offer the choice to enable AHCI (like mine :-().
> Not a problem.  You just don't get to use AHCI and such.

Huh?

My question was if there is a fundamental reason why the AHCI mode of
the ICH6/7 must be enabled by the BIOS, is there a reason why the kernel
doesn't do it, or can't do it?

And of course I'd like to have my ICH6/7 in AHCI mode, for obvious
reasons.