Re: 2.6.18-rc7-git1: AHCI not seeing devices on ICH8 mobo (DG965RY)

Robin H. Johnson
2006-09-19T06:25:23Z

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On Tue, Sep 19, 2006 at 02:06:40AM -0400, Jeff Garzik wrote:
> I don't really like this port_tbl approach. I think it complicates
> things too much.
>
> Direct indexing should be fine. For the non-linear case, just make sure
> the non-existent ports are always dummy ports. If the driver directly
> references a port we know isn't there, that's just an AHCI bug to be
> fixed...
So you think we should ignore CAP.NP and instead set our n_ports to the
position of the left-most 1-bit in PI? That would break in your case of
PI containing invalid data.

I do think a mapping is the way to go, but the implementation can
perhaps be improved a little - so that the table is local to the
probing, and is not used thereafter - because the data is stored in the
ata_ports->private_data instead.

For my hardware, note that CAP.NP was 4, and PI was (binary) 110011. By
my reading of the spec, this is correct - and says there are 4 usable
ports, located at addresses 0, 1, 4, 5.

Looking at the motherboard more closely, I do find two other unpopulated
SATA headers (also lacking the various electrical bits, so not trivial
to hack on).