Re: [Qemu-devel] [RFC v4 05/12] isa: Allow to un-associate an IRQ

["Andreas Färber" <andreas.faerber@web.de>]

Am 09.06.2011 um 17:12 schrieb Markus Armbruster:

> Markus Armbruster <armbru@redhat.com> writes:
>
>> Andreas Färber <andreas.faerber@web.de> writes:
>>
>>> Signed-off-by: Andreas Färber <andreas.faerber@web.de>
>>> ---
>>> hw/isa-bus.c |   14 ++++++++++++++
>>> hw/isa.h     |    1 +
>>> 2 files changed, 15 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/hw/isa-bus.c b/hw/isa-bus.c
>>> index 1f64673..6ac3e61 100644
>>> --- a/hw/isa-bus.c
>>> +++ b/hw/isa-bus.c
>>> @@ -80,6 +80,20 @@ void isa_init_irq(ISADevice *dev, qemu_irq *p,  
>>> int isairq)
>>>     dev->nirqs++;
>>> }
>>>
>>> +void isa_discard_irq(ISADevice *dev, int isairq)
>>> +{
>>> +    int i, j;
>>> +    for (i = 0; i < dev->nirqs; i++) {
>>> +        if (dev->isairq[i] == isairq) {
>>> +            for (j = i + 1; j < dev->nirqs; j++) {
>>> +                dev->isairq[j - 1] = dev->isairq[j];
>>> +            }
>>> +            dev->nirqs--;
>>> +            break;
>>> +        }
>>> +    }
>>> +}

> Your isa_discard_irq() keeps the qemu_irq that was set by  
> isa_init_irq()
> around, which is perhaps not perfectly clean, but should work.

We could NULL it and hope that no one uses it unchecked from some  
bottom-half or I/O thread.
Or do we have some global no-op qemu_irq?

Andreas