From 0410594ae84faa296edd65016528065c91402e62 Mon Sep 17 00:00:00 2001
From: Stefan Lankes <lankes@lfbs.rwth-aachen.de>
Date: Sat, 30 Jul 2011 22:47:27 +0200
Subject: [PATCH] fix bug in handling the timer interrupt

=> sending EOI before task switching
---
 arch/x86/kernel/irq.c   | 7 ++++++-
 arch/x86/kernel/timer.c | 7 ++-----
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index d4de077c..04ddecf4 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -253,7 +253,7 @@ void irq_handler(struct state *s)
 	 */
 	if (apic_is_enabled() || s->int_no >= 123) {
 		apic_eoi();
-		return;
+		goto leave_handler;
 	}
 
 #ifndef CONFIG_ROCKCREEK
@@ -273,4 +273,9 @@ void irq_handler(struct state *s)
 #else
 	kprintf("Upps, RockCreek uses IRQs below 123!\n");
 #endif
+
+leave_handler:
+	// timer interrupt?
+	if ((s->int_no == 32) || (s->int_no == 123))
+		scheduler(); // 	switch to a new task
 }
diff --git a/arch/x86/kernel/timer.c b/arch/x86/kernel/timer.c
index 8de626fb..251f71f8 100644
--- a/arch/x86/kernel/timer.c
+++ b/arch/x86/kernel/timer.c
@@ -69,15 +69,12 @@ static void timer_handler(struct state *s)
 #endif
 
 	/* 
-         * Every TIMER_FREQ clocks (approximately 1 second), we will
+	 * Every TIMER_FREQ clocks (approximately 1 second), we will
 	 * display a message on the screen 
-         */
+	 */
 	/*if (timer_ticks % TIMER_FREQ == 0) {
 		vga_puts("One second has passed\n");
 	}*/
-
-	// switch to a new task
-	scheduler();
 }
 
 /*