From: Ingo Molnar <mingo@elte.hu>
Date: Fri, 3 Jul 2009 08:29:57 -0500
Subject: genirq: Disable irqpoll on -rt
Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.6/older/patches-4.6.2-rt5.tar.xz

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 |    8 ++++++++
 1 file changed, 8 insertions(+)

--- a/kernel/irq/spurious.c
+++ b/kernel/irq/spurious.c
@@ -442,6 +442,10 @@ MODULE_PARM_DESC(noirqdebug, "Disable ir
 
 static int __init irqfixup_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	pr_warn("irqfixup boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+	return 1;
+#endif
 	irqfixup = 1;
 	printk(KERN_WARNING "Misrouted IRQ fixup support enabled.\n");
 	printk(KERN_WARNING "This may impact system performance.\n");
@@ -454,6 +458,10 @@ module_param(irqfixup, int, 0644);
 
 static int __init irqpoll_setup(char *str)
 {
+#ifdef CONFIG_PREEMPT_RT_BASE
+	pr_warn("irqpoll boot option not supported w/ CONFIG_PREEMPT_RT_BASE\n");
+	return 1;
+#endif
 	irqfixup = 2;
 	printk(KERN_WARNING "Misrouted IRQ fixup and polling support "
 				"enabled\n");
