Hello,

> (b) is the case. PCI does not have a generic register that indicates
> an interrupt, and reading the device-specific registers that indicate
> whether a device is responsible for the interrupt is exactly the job
> of the device's interrupt handlers (and is the reason why interrupt
> handlers return a value to say whether they handled the interrupt or
> not).
> 
> (end)
> 
> The code in extintr.c does not examine the returned value.
> 
>                 ih = is->is_hand;
>                 while (ih) {
>                         (*ih->ih_fun)(ih->ih_arg);
>                         ih = ih->ih_next;
>                 }

And the interrupt pin apparently isn't used either - the colliding devices use different pins.

have fun
Michael