Re: ACPI shutdown unreliable with win7?

[Ross Philipson <ross.philipson@gmail.com>]

On 05/29/2015 12:00 PM, Paul Durrant wrote:
>> -----Original Message-----
>> From: Ross Philipson [mailto:ross.philipson@gmail.com]
>> Sent: 29 May 2015 16:35
>> To: Ian Campbell; Paul Durrant
>> Cc: Andrew Cooper; xen-devel; Jan Beulich; Ian Jackson
>> Subject: Re: [Xen-devel] ACPI shutdown unreliable with win7?
>>
>> On 05/29/2015 11:11 AM, Ian Campbell wrote:
>>> On Fri, 2015-05-29 at 16:06 +0100, Paul Durrant wrote:
>>>>> FWIW We appear to wait 200s, if we were seeing failures due to
>> windows
>>>>> update then I'd be inclined to extend that, but I think right now that
>>>>> would be premature, unless WU happens with no status on the screen.
>>>>>
>>>>
>>>> No, you'd see something. Perhaps our ACPI lid/power switch code is just
>> buggy then?
>>>
>>> It seems to work reliably for the WinXP tests, FWIW...
>>>
>>> Ian.
>>>
>>
>> One thing I find confusing is that the firmware code does not even have
>> a power button device (PNP0C0C) or the fixed feature power button that
>> is enabled in the FADT (flag == PWR_BUTTON bit 4). So I don't see how
>> the shutdown is purely an ACPI function. Is there something else to the
>> story? Is it relying on PV tools to do it?
>>
>
> Xen (and QEMU seemingly) implement the 'Fixed Power Button' (section 4.8.2.2.1.1 on my spec) and this requires the PWR_BUTTON flag to be clear (according table 4-13). It also does not require a power button device to be implemented (which is presumably why this way of doing it was chosen).

"which is presumably why this way of doing it was chosen"

Yea it is simpler plus the power button device would then need a bunch 
of GPE plumbing to get events.

Ross
>
>    Paul
>
>> Ross
>>
>>>
>>>
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>>
>>
>> --
>> Ross Philipson


-- 
Ross Philipson