From d469482a7f28c75541942f83696e02b63e75efb6 Mon Sep 17 00:00:00 2001
From: "Justin C. Miller" <justin@devjustinian.com>
Date: Sun, 16 Sep 2018 23:50:54 -0700
Subject: [PATCH] Better spurious interrupt handling

---
 src/kernel/apic.cpp           | 2 +-
 src/kernel/interrupt_isrs.inc | 2 +-
 src/kernel/interrupts.cpp     | 4 ++++
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/src/kernel/apic.cpp b/src/kernel/apic.cpp
index 32ef3d6..b8d59cb 100644
--- a/src/kernel/apic.cpp
+++ b/src/kernel/apic.cpp
@@ -62,7 +62,7 @@ lapic::calibrate_timer()
 	outb(0x43, command);
 
 	const uint32_t initial = -1u;
-	enable_timer_internal(isr::isrIgnore0, 1, initial, false);
+	enable_timer_internal(isr::isrSpurious, 1, initial, false);
 
 	const int iterations = 5;
 	for (int i=0; i<iterations; ++i) {
diff --git a/src/kernel/interrupt_isrs.inc b/src/kernel/interrupt_isrs.inc
index 4917a4e..cb084cf 100644
--- a/src/kernel/interrupt_isrs.inc
+++ b/src/kernel/interrupt_isrs.inc
@@ -240,10 +240,10 @@ IRQ (0xdf, 0xbf, irqBF)
 ISR (0xe0, isrTimer)
 ISR (0xe1, isrLINT0)
 ISR (0xe2, isrLINT1)
-ISR (0xe3, isrSpurious)
 ISR (0xe4, isrAssert)
 
 UISR(0xee, isrSyscall)
+ISR (0xef, isrSpurious)
 
 ISR (0xf0, isrIgnore0)
 ISR (0xf1, isrIgnore1)
diff --git a/src/kernel/interrupts.cpp b/src/kernel/interrupts.cpp
index e999355..7a04d9b 100644
--- a/src/kernel/interrupts.cpp
+++ b/src/kernel/interrupts.cpp
@@ -204,6 +204,10 @@ isr_handler(addr_t return_rsp, cpu_state regs)
 		}
 		break;
 
+	case isr::isrSpurious:
+		// No EOI for the spurious interrupt
+		return return_rsp;
+
 	case isr::isrIgnore0:
 	case isr::isrIgnore1:
 	case isr::isrIgnore2: