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path: root/drivers/acpi/pci_irq.c
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Diffstat (limited to 'drivers/acpi/pci_irq.c')
-rw-r--r--drivers/acpi/pci_irq.c56
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;
}