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).

Ah got it. I read the spec backwards - that the bit was set not clear 
for the fixed feature power button :)


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


-- 
Ross Philipson