How to set irq_tables.c if a pci-to-pci bridge needed

ollie lho ollie at
Mon Oct 28 04:34:00 CET 2002

On Mon, 2002-10-28 at 16:27, David Xiong wrote:
> Hello,
> The irq_tables.c dumped from normal BIOS only have information about the pci bus 0.
> I have a multimedia card which has a pci-to-pci bridge on itself. There are 2 pci devices
> on that card. So the two devices locate at bus 2. The slot_name is 02:04.0 and 02:05.0.
> This means I have to add two devices into the irq_tables.c. 
> I added two lines like this:
>   {0x2,0x20,{0x41,0xceb8},{0x42,0xceb8},{0x43,0xceb8},{0x44,0xceb8}},0,0},
>   {0x2,0x28,{0x42,0xceb8},{0x43,0xceb8},{0x44,0xceb8},{0x41,0xceb8}},0,0},
> Then I make linuxbios again , it seems everything is OK when I boot. The two devices are
> assigned interrupt numbers successfully. But they can't work.

Did you recalculate the checksum ??

> The chipset is SiS630e and the mother board is elite p6vem3. I guess the problem is in the two lines added into irq_tables.c as above.
> So I modify them to 
>   {0x2,0x20,{0x44,0xceb8},{0x41,0xceb8},{0x42,0xceb8},{0x43,0xceb8}},0,0},
>   {0x2,0x28,{0x41,0xceb8},{0x42,0xceb8},{0x43,0xceb8},{0x44,0xceb8}},0,0},
> but g the two devices still did not work.

Where did you get the idea to set the the table like this. Do you have 
any documentation about your bridge ?? How did you know if your bridge
does not re-route IRQs in some other ways ??


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