Re: x86: Increase PCIBIOS_MIN_IO to 0x1500 to fix nForce 4 suspend-to-RAM

From: Carlos Corbacho
Date: Tue Dec 25 2007 - 08:12:56 EST


On Tuesday 25 December 2007 13:26:12 Rafael J. Wysocki wrote:
> Well, citing from the ACPI 2.0 specification, section 9.1.6 Transitioning
> from the Working to the Sleeping State (which is what we're discussing
> here):
>
> 3. OSPM places all device drivers into their respective Dx state. If the
> device is enabled for wake, it enters the Dx state associated with the wake
> capability. If the device is not enabled to wake the system, it enters the
> D3 state.
> 4. OSPM executes the _PTS control method, passing an argument that
> indicates the desired sleeping state (1, 2, 3, or 4 representing S1, S2,
> S3, and S4).
>
> My opinion is that we should follow this part of the specification and so
> we do.

This is that same section from ACPI 1.0B:

3. The OS executes the Prepare To Sleep (_PTS) control method, passing an
argument that indicates the desired sleeping state (1, 2, 3, or 4 representing
S1, S2, S3, and S4).

4. The OS places all device drivers into their respective Dx state. If the
device is enabled for wakeup, it enters the Dx state associated with the
wakeup capability. If the device is not enabled to wakeup the system, it
enters the D3 state.

The DSDTs in question also claim ACPI 1.0 compatiblity.

> You're wrong, sorry.

No, I'm not entirely wrong - read the 1.0 spec, and read section 7.3.2 of the
ACPI 2.0 spec.

* ACPI 1.0 is very clear - we are breaking the 1.0 spec

* ACPI 2.0 is contradictory - section 7.3.2 repeats 1.0 ad verbatim (which is
what I quote in reply to Robert Hancock), but as you point out, 9.3.2 says
the opposite.

So, 1.0 and 3.0 are very clear and rather different on this, and 2.0 is
contradictory (and I presume this is one of the points ACPI 3.0 set out to
clean up).

I will rescind my point on ACPI 2.0 - I don't know what we should or shouldn't
be doing there, the spec is unclear.

But for ACPI 1.0, we are doing the wrong thing.

-Carlos
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