It seems that linuxbios (and linux) uses the irq routing tables dumped from the bios mptable. Are there any good reasons to reroute 9 pci/agp interrupts (2 64-bit slots on the first pci bus + 1 agp + 4 32-bit slots + builtin ethernet on the second pci bus) to 4 apic pins 16,17,18,19 when at least the pins 5,9,10,11 are not used at all ? Now i have 3 devices sharing pin 19, and 2 devices on 16,17 and 18. Is this the intended use of io-apic ?
Oleg.
On Thu, 2003-07-24 at 04:37, Oleg Gusev wrote:
It seems that linuxbios (and linux) uses the irq routing tables dumped from the bios mptable. Are there any good reasons to reroute 9 pci/agp interrupts (2 64-bit slots on the first pci bus + 1 agp + 4 32-bit slots + builtin ethernet on the second pci bus) to 4 apic pins 16,17,18,19 when at least the pins 5,9,10,11 are not used at all ? Now i have 3 devices sharing pin 19, and 2 devices on 16,17 and 18. Is this the intended use of io-apic ?
Well, PCI spec only defines 4 IRQ Lines (A,B,C,D) and these lines are supposed to be shareable. These 4 lines are connected to 4 IRQ pins on the apic. As a result, even apic has 24 irq pins, we allocate 4 pins for PCI devices.
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Oleg Gusev -
ollie lho