[Qemu-devel] Re: [PATCH 8/8] ahci: fix !msi interrupts

[Jan Kiszka]

On 2011-01-17 17:00, Alexander Graf wrote:
> Jan Kiszka wrote:
>> On 2010-12-20 22:13, Alexander Graf wrote:
>>   
>>> When not using MSI, receiving an interrupt while the interrupt line is 
>>> active
>>> pulses the interrupt line. Without this, guests don't realize that a new
>>> interrupt occured.
>>>     
>>
>> This doesn't look OK. The device model should look at the currently used
>> mode and switch between edge and level triggering accordingly. As it
>> appears like this is what it already does, this change may just paper
>> over the real issue.
>>   
> 
> Well, I have this internal abstraction to make edge and level triggered
> interrupt triggering easier. irq_lower is a simple nop for the edge case.
> 

I'm concerned about the artificial edge you generate for the level
triggered case. That's not like real hw behaves. If you need it,
something else might still be broken.

Jan

-- 
Siemens AG, Corporate Technology, CT T DE IT 1
Corporate Competence Center Embedded Linux