Re: [Qemu-devel] [PATCH 11/22] i8259: Update IRQ state after reset

[Blue Swirl]

On Sun, Oct 2, 2011 at 7:07 PM, Avi Kivity <address@hidden> wrote:
>> >
>> > The way to fix it is two-phase reset:
>> >
>> > phase 1: reset internal state (-> move all outputs to reset
>> > values),
>> > don't sample inputs yet
>> > phase 2: allow sampling inputs
>>
>> As far as I understood Anthony's QOM plans, phase 1 will correspond
>> to
>> "unrealize", phase 2 to "realize".
>
> That smells of abusing mechanism used for construction for reset purposes.
>
> Why not use an ordinary qemu_irq?  It reresents a pin; 0->1 edge (assert) 
> enters phase 1, 1->0 edge (deassert) enters phase 2.  Exactly like real 
> hardware.

Fully agree. I also proposed using qemu_irq for reset (but without
phases) a long time ago.

>>
>> However, we do not depend on two phases in this particular case
>> (i8259)
>> and can live with a coalescing both for now.
>>
>
> Agree.
>