Subject: Re: SmartFirmware interrupts
To: Matt Sealey <matt@genesi-usa.com>
From: Frank Wille <frank@phoenix.owl.de>
List: port-ofppc
Date: 10/20/2007 12:22:23
Matt Sealey wrote:

>> Er... you didn't reply to my question? AFAIK a 8259 has two
>> 8-bit registers. Where would I find them? Especially from the
>> second, cascaded 8259?
>> 
>> But interesting to know the IRQ. So we will hardcode this into
>> the kernel? :P
>> 
>> And is it really desirable that all PCI devices have to share
>> the same interrupt?
> 
> *bashes my head on the desk*
> 
> PCI devices have to share IRQ9, it's the law. They do this on ACPI systems
> too.

All PCI devices, even the ones integrated on the motherboard? On the PCs I
checked many other IRQs are used by PCI devices (for example 5 or 10).

In another thread I have read that this really causes problems on the Pegasos
(packet loss on network, for example), but I will not complain. I only need
the facts for a port.


> If they are not in the device tree, check the VT8231 datasheet.

Ok. The ISA devices are not the problem. The datasheet is available and there
is even the interrupt number in the OFW tree.


> [...] I don't really understand why this
> is such a big deal. It never was for Linux..

Maybe because there were bPlan employees involved in the Linux Ports (e.g.
Nicolas Det)? Then it is no problem to have all internal information you
need at any time...

For us the Pegasos (and the Efika) is a black box, and we need some effort
to understand everything. Sorry when I'm a bit slow at it. :P


>> Tell me where to find the interrupts for IDE or USB in the
>> device tree of 1.2. Exact path and property name. Seems I'm
>> not the only one who is too blind... :|
> 
> "interrupts" property.

It tells me 1 for firewire, 1 for ide, 4 for usb and 3 for sound. Which
means...?

I guess it is the PCI interrupt line number (usually there are four), not
the IRQ on the PIC.


-- 
    _  Frank Wille (frank@phoenix.owl.de)
 _ //  http://sun.hasenbraten.de/~frank/
 \X/   Phx @ #AmigaGer