[Soekris] net45xx interrupt routing?

Trevor Talbot quension at mac.com
Sat Aug 2 19:48:50 UTC 2003


On Saturday, Aug 2, 2003, at 02:46 US/Pacific, Bernd Walter wrote:

> On Fri, Aug 01, 2003 at 11:06:48PM -0700, Trevor Talbot wrote:
>> On Friday, Aug 1, 2003, at 18:50 US/Pacific, Bernd Walter wrote:
>>
>>> On Fri, Aug 01, 2003 at 03:30:24PM -0700, Trevor Talbot wrote:
>>>>> I'm looking for info on how the physical interrupt lines are 
>>>>> connected.  E.g. on the net4501, the CF controller gets GP10, and 
>>>>> the three ethernet controllers get PCI C, B, and A.  What about 
>>>>> the mini and full PCI slots, and how does the net4521 differ?
>>>
>>> PCI chips always get INTA first, but INTA can be differently routed 
>>> for different slot IDs.
>>
>> That's why I wanted the memory dump from BIOS.  It shows how the 
>> Elan's PIC is routing the physical lines.
>
> Here is it from a 4501 (comBIOS ver. 1.15):
>> db fffefd30
> 0000:FFFEFD30  04 0D 06 00 00 00 00 00 00 00 00 00 00 00 00 00

> 0000:FFFEFD50  00 00 00 00 00 00 00 00 00 05 09 00 20 00 20 00

This is interesting.  INTD isn't used, and GP9 is routed to IRQ10.  
Which slot was in use?

>>> Here are the important lines from FreeBSD:
>>> hifn0 mem 0xa0001000-0xa0001fff,0xa0000000-0xa0000fff irq 10 at 
>>> device 16.0 on pci0
>>> ohci0: <NEC uPD 9210 USB controller> mem 0xa0000000-0xa0000fff irq 
>>> 10 at device 17.0 on pci0
>>> ohci1: <NEC uPD 9210 USB controller> mem 0xa0001000-0xa0001fff irq 
>>> 10 at device 17.1 on pci0
>>
>> These got mapped into the same space?  That doesn't look right...
>
> Ignore the mem ranges - hifn and usb cards were no plugged in at the 
> same boot - the messages were concatenated from different saved logs.
> But I remember the IRQs were the same when I had both in.

Ah.  The BIOS seems to assign IRQ10 first; I have a net4501 here with 
no cards, and the three ethernet controllers get IRQs 10, 11, and 5.  
Since one of the slots is on GP9 (which seems like an odd arbitrary 
choice if INTD is available), I wonder if both are on GP9, or if BIOS 
just routed both to IRQ10 for some reason.




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