Re: [PATCH 3/6] qemu: piix: Introduce functions to get pin number from irq and vice versa

[Muli Ben-Yehuda <muli@il.ibm.com>]

On Tue, Oct 28, 2008 at 12:46:39PM +0200, Avi Kivity wrote:
> Muli Ben-Yehuda wrote:
>> On Sun, Oct 26, 2008 at 03:31:24PM +0200, Avi Kivity wrote:
>>   
>>> Amit Shah wrote:
>>>     
>>>>  +int piix3_get_pin(int pic_irq)
>>>> +{
>>>> +    int i;
>>>> +    for (i = 0; i < 4; i++)
>>>> +        if (piix3_dev->config[0x60+i] == pic_irq)
>>>> +            return i;
>>>> +    return -1;
>>>> +}
>>>>         
>>> What happens if two pci interrupts are routed to one irq line?
>>>     
>>
>> This one I'm still thinking about.
>>   
>
> Well, what is this needed for in the first place?

This specific function is not used. I assume Amit added it for
completeness with piix_get_irq. piix_get_irq, as far as I can tell, is
used in only one place (when the guest updates a device's
configuration space interrupt register) to go from interrupt pin
(intx) to guest IRQ line.

Cheers,
Muli
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