Re: [Patch v2] x86, ACPI, irq: Add a quirk to override SCI polarity for HyperV

[Jiang Liu <jiang.liu@linux.intel.com>]

On 2015/8/19 16:40, Thomas Gleixner wrote:
> On Wed, 19 Aug 2015, Thomas Gleixner wrote:
>> On Wed, 19 Aug 2015, Jiang Liu wrote:
>>> On 2015/8/19 14:45, Rafael J. Wysocki wrote:
>>>> Well, the regression at hand has just shown that the assertion in the
>>>> changelog of that commit ("no need for for special treatment for GSI
>>>> used by ACPI SCI") does not really hold.  So, if the only motivation
>>>> for it was to get rid of one extra check in mp_unregister_gsi()
>>>> (mp_register_gsi() still needs to check if it is dealing with the SCI
>>>> anyway), I'd vote for reverting it.
>>> Hi Rafael,
>>> 	The motivation is to treat SCI as normal IOAPIC interrupt so
>>> we could enforce stricter pin attribute checking. Now it does reveal
>>> flaws in ACPI BIOS implementations, but we ran into trouble about how to
>>> handle those flaws:(
>>
>> The intent of this change is entirely correct, though it seems that
>> reality of ACPI is just different.
>>
>> To be on the safe side of things, I agree with Rafael that we should
>> revert that patch instead of introducing a single platform quirk.
> 
> Jiang,
> 
> can you please prepare a revert patch for this?
Sure, will send out revert patch after basic tests.