diff --git a/arch/x86/lib/mpspec.c b/arch/x86/lib/mpspec.c
index 9b2a59b911..f3ad116316 100644
--- a/arch/x86/lib/mpspec.c
+++ b/arch/x86/lib/mpspec.c
@@ -21,6 +21,8 @@
 
 DECLARE_GLOBAL_DATA_PTR;
 
+static bool isa_irq_occupied[16];
+
 struct mp_config_table *mp_write_floating_table(struct mp_floating_table *mf)
 {
 	u32 mc;
@@ -243,10 +245,18 @@ static void mptable_add_isa_interrupts(struct mp_config_table *mc, int bus_isa,
 			MP_IRQ_TRIGGER_EDGE | MP_IRQ_POLARITY_HIGH,
 			bus_isa, 0, apicid, 2);
 
-	for (i = 3; i < 16; i++)
+	for (i = 3; i < 16; i++) {
+		/*
+		 * Do not write ISA interrupt entry if it is already occupied
+		 * by the platform devices.
+		 */
+		if (isa_irq_occupied[i])
+			continue;
+
 		mp_write_intsrc(mc, MP_INT,
 				MP_IRQ_TRIGGER_EDGE | MP_IRQ_POLARITY_HIGH,
 				bus_isa, i, apicid, i);
+	}
 }
 
 /*
@@ -287,10 +297,6 @@ static int mptable_add_intsrc(struct mp_config_table *mc,
 	const u32 *cell;
 	int i;
 
-	/* Legacy Interrupts */
-	debug("Writing ISA IRQs\n");
-	mptable_add_isa_interrupts(mc, bus_isa, apicid, 0);
-
 	/* Get I/O interrupt information from device tree */
 	node = fdtdec_next_compatible(blob, 0, COMPAT_INTEL_IRQ_ROUTER);
 	if (node < 0) {
@@ -330,12 +336,22 @@ static int mptable_add_intsrc(struct mp_config_table *mc,
 		}
 
 		dstirq = mp_determine_pci_dstirq(bus, dev, func, pr.pirq);
+		/*
+		 * For PIRQ which is connected to I/O APIC interrupt pin#0-15,
+		 * mark it as occupied so that we can skip it later.
+		 */
+		if (dstirq < 16)
+			isa_irq_occupied[dstirq] = true;
 		mp_write_pci_intsrc(mc, MP_INT, bus, dev, pr.pin,
 				    apicid, dstirq);
 		intsrc_entries++;
 		cell += sizeof(struct pirq_routing) / sizeof(u32);
 	}
 
+	/* Legacy Interrupts */
+	debug("Writing ISA IRQs\n");
+	mptable_add_isa_interrupts(mc, bus_isa, apicid, 0);
+
 	return 0;
 }