Hello all! I have a question about how the kernel assigns interrupt levels to PCI cards. I think that lines like these: <6>PCI->APIC IRQ transform: 0000:00:1f.1[A] -> IRQ 169 means that the device at PCI address 0000:00:1f.1 is assigned the interrupt 169 on the APIC board. So when I boot, I get these dmesg:es: <4>PCI: Probing PCI hardware <7>PCI: Probing PCI hardware (bus 00) <4>PCI quirk: region 0600-067f claimed by ICH4 ACPI/GPIO/TCO <4>PCI quirk: region 0700-073f claimed by ICH4 GPIO <6>PCI: Ignoring BAR0-3 of IDE controller 0000:00:1f.1 <6>PCI: Transparent bridge - 0000:00:1e.0 <6>PCI: Using IRQ router PIIX/ICH [8086/24c0] at 0000:00:1f.0 <6>PCI->APIC IRQ transform: 0000:00:1f.1[A] -> IRQ 169 <6>PCI->APIC IRQ transform: 0000:00:1f.3[B] -> IRQ 161 <6>PCI->APIC IRQ transform: 0000:03:02.0[A] -> IRQ 177 <6>PCI->APIC IRQ transform: 0000:03:02.1[B] -> IRQ 185 <6>PCI->APIC IRQ transform: 0000:03:03.0[A] -> IRQ 193 <6>PCI->APIC IRQ transform: 0000:03:03.1[B] -> IRQ 201 <6>PCI->APIC IRQ transform: 0000:03:04.0[A] -> IRQ 209 So 7 IRQ:s are assigned to four PCI devices. But in another boot: <4>PCI: Probing PCI hardware <7>PCI: Probing PCI hardware (bus 00) <4>PCI quirk: region 0600-067f claimed by ICH4 ACPI/GPIO/TCO <4>PCI quirk: region 0700-073f claimed by ICH4 GPIO <6>PCI: Ignoring BAR0-3 of IDE controller 0000:00:1f.1 <6>PCI: Transparent bridge - 0000:00:1e.0 <6>PCI: Using IRQ router PIIX/ICH [8086/24c0] at 0000:00:1f.0 <6>PCI->APIC IRQ transform: 0000:00:1f.1[A] -> IRQ 169 <6>PCI->APIC IRQ transform: 0000:00:1f.3[B] -> IRQ 161 <6>PCI->APIC IRQ transform: 0000:03:02.0[A] -> IRQ 177 <6>PCI->APIC IRQ transform: 0000:03:02.1[B] -> IRQ 185 <6>PCI->APIC IRQ transform: 0000:03:03.0[A] -> IRQ 193 <6>PCI->APIC IRQ transform: 0000:03:03.1[B] -> IRQ 201 Only 6 IRQ:s are assigned?! This is very strange and I can find no reasonable explanation why one less IRQ shows up. Could this be a hardware problem and does it matter which PCI devices are attached to those addresses? -- mvh Björn -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
