Re: [Qemu-devel] [PATCH v14 7/9] ARM: ACPI: Add GPIO notification type for hardware RAS error

[gengdongjiu]

On 2018/1/3 21:36, Igor Mammedov wrote:
> On Wed, 3 Jan 2018 11:48:30 +0800
> gengdongjiu <address@hidden> wrote:
> 
>> On 2017/12/28 22:53, Igor Mammedov wrote:
>>> On Thu, 28 Dec 2017 13:54:16 +0800
>>> Dongjiu Geng <address@hidden> wrote:
> [...]
>>>> +static void acpi_dsdt_add_error_device(Aml *scope)
>>>> +{
>>>> +    Aml *dev = aml_device(ACPI_HARDWARE_ERROR_DEVICE);
>>>> +    Aml *method;
>>>> +
>>>> +    aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0C33")));
>>>> +    aml_append(dev, aml_name_decl("_UID", aml_int(0)));
>>>> +
>>>> +    method = aml_method("_STA", 0, AML_NOTSERIALIZED);
>>>> +    aml_append(method, aml_return(aml_int(0x0f)));  
>>> no need for dummy _STA method, device is assumed to be present if there is 
>>> no _STA   
>> Igor,
>>   do you mean remove above two line code as shown in [1]?
>> I dump the DSDT table in my host Ubuntu PC for the error device (PNP0C33), 
>> it has the _STA, as shown in [2].
>> do we not want to add the _STA for guest?
>>
>> [1]
>> +    method = aml_method("_STA", 0, AML_NOTSERIALIZED);
>> +    aml_append(method, aml_return(aml_int(0x0f)));
> compared to host, yours method does nothing,
> read ACPI6.2 "6.3.7 _STA (Status)" one more time
Thanks for the pointing out.
yes, you are right. As the spec statement[1], Device is assumed to be present 
if there is no _STA.

[1]:
ACPI6.2 "6.3.7 _STA (Status), Return Value Information"
If a device object (including the processor object) does not have an _STA 
object, then OSPM
assumes that all of the above bits are set (i.e., the device is present, 
enabled, shown in the UI,
and functioning).

> 
>> [2]:
>>         Device (WERR)
>>         {
>>             Name (_HID, EisaId ("PNP0C33"))  // _HID: Hardware ID
>>             Method (_STA, 0, NotSerialized)  // _STA: Status
>>             {
>>                 If (LGreaterEqual (OSYS, 0x07D9))
>>                 {
>>                     Return (0x0F)
>>                 }
>>                 Else
>>                 {
>>                     Return (Zero)
>>                 }
>>             }
>>         }
>>>   
>>>> +    aml_append(dev, method);
>>>> +    aml_append(scope, dev);
>>>> +}
>>>> +
> [...]
> 
> 
> .
>