Re: [PATCH[RFC] Quirk macbook pro 6,2 into ahci mode

[Jeff Garzik]

On 07/18/2010 02:42 PM, Matthew Garrett wrote:
> On Sun, Jul 18, 2010 at 10:03:44AM -0600, Jens Axboe wrote:
> > Looking at the specs, I don't see what I am missing to make this
> > work for resume. I'm assuming that EFI did initialize some bits
> > that am missing when coming out of resume, but I don't know which
> > bits.
>
> There's no guarantee that the AHCI BAR is programmed by the firmware (it
> seems to be on the Macs, but won't be on most hardware). Is it getting
> reprogrammed on resume?

That's definitely the key question.

I would have quirked AHCI/piix hardware into AHCI mode long ago, if 
firmwares defaulting to piix mode would actually program the PCI BAR 
correctly.

Or, if the firmware had some way to safely allocate a bus memory range, 
which we could ourselves program into the PCI BAR.  Some non-PC 
platforms can do that.

	Jeff


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