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

[Andreas Färber]

Am 09.06.2011 um 17:12 schrieb Markus Armbruster:

> Markus Armbruster <address@hidden> writes:
>
> > Andreas Färber <address@hidden> writes:
> >
> > > Signed-off-by: Andreas Färber <address@hidden>
> > > ---
> > > 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