Re: [RFC PATCH v2 5/8] libata-acpi: add ata port runtime D3Cold support

[Aaron Lu <aaron.lu@amd.com>]

On Mon, Mar 19, 2012 at 03:03:40PM +0800, Lin Ming wrote:
> > 
> > Sorry I didn't make it clear.
> > The problem here is, we are going to set the device power state to D3
> > cold, and current OSPM has no support for it.
> > 
> > Another patch of yours solved this problem by defining:
> > 1 Device supports D3 cold if it has _PR3;
> > 2 For a device to be put to D3 cold, power off all the power resources
> > referenced in its _PR3.
> > 
> > Since this can't work for AMD's platform(there is no _PR3 for the sata
> > acpi device), I would like to change this a little bit:
> > 1 Device supports D3 cold if it has _PR3 or _PS3;
> 
> _PS3 may only mean D3Hot support for other device.
> 
> You mentioned that AMD platform defined a special device, named ODDZ.
> 
> How about device supports D3 cold if
> 
> _PR3 or (is ODDZ and ODDZ._PS3)?

Sounds good, I'll do this, thanks.

> 
> > 2 For a device to be put to D3 cold, execute _PS3 first if available and
> > then deal with _PR3 as above.
> 
> __acpi_bus_set_power(...) has done this.
> 

Actually not, current implementation of __acpi_bus_set_power will call
_PS4 ;-)
I'll need to think of a way to handle the D3 cold case.

-Aaron