diff options
Diffstat (limited to 'drivers/acpi/pci_irq.c')
| -rw-r--r-- | drivers/acpi/pci_irq.c | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index 11acaee14d6..bf79d83bdfb 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -384,6 +384,27 @@ acpi_pci_free_irq(struct acpi_prt_entry *entry, return irq; } +#ifdef CONFIG_X86_IO_APIC +extern int noioapicquirk; + +static int bridge_has_boot_interrupt_variant(struct pci_bus *bus) +{ + struct pci_bus *bus_it; + + for (bus_it = bus ; bus_it ; bus_it = bus_it->parent) { + if (!bus_it->self) + return 0; + + printk(KERN_INFO "vendor=%04x device=%04x\n", bus_it->self->vendor, + bus_it->self->device); + + if (bus_it->self->irq_reroute_variant) + return bus_it->self->irq_reroute_variant; + } + return 0; +} +#endif /* CONFIG_X86_IO_APIC */ + /* * acpi_pci_irq_lookup * success: return IRQ >= 0 @@ -413,6 +434,41 @@ acpi_pci_irq_lookup(struct pci_bus *bus, } ret = func(entry, triggering, polarity, link); + +#ifdef CONFIG_X86_IO_APIC + /* + * Some chipsets (e.g. intel 6700PXH) generate a legacy INTx when the + * IRQ entry in the chipset's IO-APIC is masked (as, e.g. the RT kernel + * does during interrupt handling). When this INTx generation cannot be + * disabled, we reroute these interrupts to their legacy equivalent to + * get rid of spurious interrupts. + */ + if (!noioapicquirk) { + switch (bridge_has_boot_interrupt_variant(bus)) { + case 0: + /* no rerouting necessary */ + break; + + case INTEL_IRQ_REROUTE_VARIANT: + /* + * Remap according to INTx routing table in 6700PXH + * specs, intel order number 302628-002, section + * 2.15.2. Other chipsets (80332, ...) have the same + * mapping and are handled here as well. + */ + printk(KERN_INFO "pci irq %d -> rerouted to legacy " + "irq %d\n", ret, (ret % 4) + 16); + ret = (ret % 4) + 16; + break; + + default: + printk(KERN_INFO "not rerouting irq %d to legacy irq: " + "unknown mapping\n", ret); + break; + } + } +#endif /* CONFIG_X86_IO_APIC */ + return ret; } |