Re: [Qemu-devel] [PATCH 1.0] ac97: don't override the pci subsystem id

[Anthony Liguori <anthony@codemonkey.ws>]

On 11/07/2011 08:50 AM, Avi Kivity wrote:
> On 11/07/2011 04:44 PM, Anthony Liguori wrote:
>>>>> This a guest ABI change.  Do we want -M support for it?
>>>>
>>>> Given that the old subsystem id isn't valid I'd say no unless someone
>>>> comes up with a good reason.
>>>
>>> Do we know that Windows won't complain about it?
>>
>>
>> I thought the original motivation for the default subsystem ids was
>> that some Windows test suite was explicitly complaining about having
>> invalid subsystem ids?
>
> I think so, but that's unrelated.  The worry is that some DRM code
> checksums your hardware and complains if it changed too much.  Nothing
> to do with the test suite.
>
> The sense of Gerd's comment is reversed.  We should preserve the ABI
> unless there is a strong reason not to.

Yes, I understand where you're coming from and I agree except when it comes to 
bug fixes.

My view toward bug fixes is the opposite--unless we know that the bug fix breaks 
something, we should fix the bug. If it's a bug, we have to assume it's breaking 
something.

Regards,

Anthony Liguori