[PATCH] x86, irq: Fix regression caused by commit b568b8601f05

[Jiang Liu <jiang.liu@linux.intel.com>]

Commit b568b8601f05 ("Treat SCI interrupt as normal GSI interrupt")
accidently removes support of legacy PIC interrupt when fixing a
regression for Xen, which causes a nasty regression on HP/Compaq
nc6000 where we fail to register the ACPI interrupt, and thus
lose eg. thermal notifications leading a potentially overheated
machine.

So reintroduce support of legacy PIC based ACPI SCI interrupt.

Reported-by: Ville Syrjälä <syrjala@sci.fi>
Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
---
Hi Ville,
	Could you please help to try this patch instead of revert commit
b568b8601f05?
Thanks!
Gerry
---
 arch/x86/kernel/acpi/boot.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index ae97ed0873c6..3d525c6124f6 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -613,6 +613,11 @@ int acpi_gsi_to_irq(u32 gsi, unsigned int *irqp)
 {
 	int rc, irq, trigger, polarity;
 
+	if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {
+		*irqp = gsi;
+		return 0;
+	}
+
 	rc = acpi_get_override_irq(gsi, &trigger, &polarity);
 	if (rc == 0) {
 		trigger = trigger ? ACPI_LEVEL_SENSITIVE : ACPI_EDGE_SENSITIVE;
-- 
1.7.10.4