Re: [gentoo-user] AHCI/IDE-question

Hi Mike,

thank you for your explanations! :)

But....


Mike Edenfield <kutulu@××××××.org> [11-01-21 21:48]:
> On 1/21/2011 3:05 PM, meino.cramer@×××.de wrote:
>
> >     solfire:/root>dmesg | grep -i ahci
> >     ahci 0000:00:11.0: version 3.0
> > *0* ahci 0000:00:11.0: PCI INT A -> GSI 19 (level, low) -> IRQ 19
> > *1* ahci 0000:00:11.0: irq 78 for MSI/MSI-X
> > *2* ahci 0000:00:11.0: AHCI 0001.0200 32 slots 6 ports 3 Gbps 0x3f impl SATA mode
> > *3* ahci 0000:00:11.0: flags: 64bit ncq sntf ilck pm led clo pmp pio slum part
>
> >     ahci 0000:07:00.0: PCI INT A -> GSI 44 (level, low) -> IRQ 44
> > *4* ahci 0000:07:00.0: AHCI 0001.0000 32 slots 2 ports 3 Gbps 0x3 impl SATA mode
> > *5* ahci 0000:07:00.0: flags: 64bit ncq pm led clo pmp pio slum part
> > *6* ahci 0000:07:00.0: setting latency timer to 64
>
> > For me bare eye this looks like the kernel ha switched all seven ports
> > to AHCI.
>
> To say that the kernel "switched" the ports is probably misleading.  The
> kernel is just trying to hook up the devices it finds to the device
> drivers it has available.
>
> You told the kernel it was ok to use the AHCI driver.  The kernel
> located those ports, detected that they supported the AHCI interface,
> and thus, attached the AHCI SATA driver to them.  If you had told your
> BIOS that those ports should be operated as IDE instead of AHCI, then
> the kernel wouldn't have found any supported AHCI hardware and you
> probably wouldn't be able to boot.

.....before the BIOS was set to IDE the kernel used AHCI.
After switching the BIOS to AHCI the kernel acts identical to 
what it did before.

So it seems, that the BIOS has no influence. Mark mentioned this
before.

Only switching the kernel to IDE (only for experimenting) leads
to a non-bootable system.


> > Why is line *1* of the first block missing in the second block,
> > Volker? Why is line *2* talking about "0x3f" while line  *4* is using
> > "0x3", Volker? Why differ line *5* from line *3*, Volker? What does
> > all these flags mean?
>
> You could also dig into the internals of the libahci.c driver to figure
> out what all of those display items mean.  In this case, your seeing two
> different PCI busses with slightly different capabilities; just off the
> top of my head, one is probably a 6-port PCI-X bus and the other a
> 2-port PCI bus, but I'd have to go look up the specs to your motherboard
> to really find out.

Ok, I save this for tommorrow. Here it is now 21r:59 in the evening
and I stood up 3:40 this night/morning today.
I think, there is enough AHCI and IDE left for tommorow... :)


> --Mike
>

Thanks to you all who have helped ! 

mcc