diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 872a2d255e41..81aa73b8ecf5 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -1120,6 +1120,7 @@ int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
 	int ioapic;
 	int ioapic_pin;
 	struct io_apic_irq_attr irq_attr;
+	int ret;
 
 	if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
 		return gsi;
@@ -1149,7 +1150,9 @@ int mp_register_gsi(struct device *dev, u32 gsi, int trigger, int polarity)
 	set_io_apic_irq_attr(&irq_attr, ioapic, ioapic_pin,
 			     trigger == ACPI_EDGE_SENSITIVE ? 0 : 1,
 			     polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
-	io_apic_set_pci_routing(dev, gsi_to_irq(gsi), &irq_attr);
+	ret = io_apic_set_pci_routing(dev, gsi_to_irq(gsi), &irq_attr);
+	if (ret < 0)
+		gsi = INT_MIN;
 
 	return gsi;
 }
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index 260abc2f9eeb..e63a5bd2a78f 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -3380,12 +3380,15 @@ int io_apic_setup_irq_pin_once(unsigned int irq, int node,
 {
 	unsigned int ioapic_idx = attr->ioapic, pin = attr->ioapic_pin;
 	int ret;
+	struct IO_APIC_route_entry orig_entry;
 
 	/* Avoid redundant programming */
 	if (test_bit(pin, ioapics[ioapic_idx].pin_programmed)) {
-		pr_debug("Pin %d-%d already programmed\n",
-			 mpc_ioapic_id(ioapic_idx), pin);
-		return 0;
+		pr_debug("Pin %d-%d already programmed\n", mpc_ioapic_id(ioapic_idx), pin);
+		orig_entry = ioapic_read_entry(attr->ioapic, pin);
+		if (attr->trigger == orig_entry.trigger && attr->polarity == orig_entry.polarity)
+			return 0;
+		return -EBUSY;
 	}
 	ret = io_apic_setup_irq_pin(irq, node, attr);
 	if (!ret)