From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:57 -0500
Subject: genirq: disable irqpoll on -rt

Creates long latencies for no value

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 kernel/irq/spurious.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

Index: linux-stable/kernel/irq/spurious.c
===================================================================
--- linux-stable.orig/kernel/irq/spurious.c
+++ linux-stable/kernel/irq/spurious.c
@@ -341,6 +341,11 @@ MODULE_PARM_DESC(noirqdebug, "Disable ir
 
 static int __init irqfixup_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	printk(KERN_WARNING "irqfixup boot option not supported "
+		"w/ CONFIG_PREEMPT_RT\n");
+	return 1;
+#endif
 	irqfixup = 1;
 	printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
 	printk(KERN_WARNING "This may impact system performance.\n");
@@ -353,6 +358,11 @@ module_param(irqfixup, int, 0644);
 
 static int __init irqpoll_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	printk(KERN_WARNING "irqpoll boot option not supported "
+		"w/ CONFIG_PREEMPT_RT\n");
+	return 1;
+#endif
 	irqfixup = 2;
 	printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
 				"enabled\n");