Re: [ACPI] Re: RFC: ACPI/scsi/libata integration and hotswap

[Jeff Garzik]

Alan Cox wrote:
> On Iau, 2005-12-08 at 08:52 -0500, Jeff Garzik wrote:
>
> > On Thu, Dec 08, 2005 at 01:39:45PM +0000, Matthew Garrett wrote:
> >
> > > On Thu, Dec 08, 2005 at 01:33:08PM +0000, Christoph Hellwig wrote:
> > >
> > >
> > > > Don't do it at all.  We don't need to fuck up every layer and driver for
> > > > intels braindamage.
> > >
> > > Doing SATA suspend/resume properly on x86 depends on knowing the ACPI 
> > > object that corresponds to a host or target.
> >
> > Not true.
>
>
>
> Actually he is right. You have to know the ACPI object in order to run
> the _GTM/_STM etc functions. If you don't run those your suspend/resume

These are only for PATA.  We don't care about _GTM/_STM on SATA.

Further, SATA completely resets and re-initializes the device as if from 
a hardware reset (except on ata_piix, which doesn't support COMRESET, 
and PATA).  This makes _GTF uninteresting, as well.


> may not work, may corrupt and so on. The only safe alternative is to
> disable acpi which, while it would have been a good idea before the spec
> ever got out, is a bit late now.

suspend/resume works just fine with Jens' out-of-tree patch.


> If you don't run the resume methods your disk subsystem status after a
> resume is simply undefined and unsafe.

I initialize the hardware to a defined state.

	Jeff


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