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

[Avi Kivity]

> >
> > Can you give an example?  Can be theoretical, doesn't have to refer
> > to real hardware.
>
> For example, outputs A and B should both be driven high by reset.
> They
> are connected to a XNOR gate, whose output is fed to edge triggered
> device. The device should not see any edges outside of the reset
> cycle, during reset cycle they are ignored.
>

I don't see the issue?  After phase 1 the two outputs will be high, after phase 
two they will be whatever the device logic computes.

During phase 1 you may see an edge, but that also happens with real hardware.  
The target device my see A and B driven high before it sees the reset pulse, 
and A and B (and the inputs of the XNOR gate) may have different timings.

The device may see an edge immediately before reset, but then it will be reset 
itself.