UBUNTU: SAUCE: allow IRQs to be irq-threaded by default via config

Signed-off-by: Andy Whitcroft <apw@canonical.com>

kernel/irq/Kconfig

@@ -91,6 +91,10 @@ config IRQ_DOMAIN_DEBUG
 config IRQ_FORCED_THREADING
        bool
 
+config IRQ_FORCED_THREADING_DEFAULT
+	bool "Use IRQ threading by default"
+	depends on IRQ_FORCED_THREADING
+
 config SPARSE_IRQ
 	bool "Support sparse irq numbering" if MAY_HAVE_SPARSE_IRQ
 	---help---

kernel/irq/manage.c

@@ -22,14 +22,20 @@
 #include "internals.h"
 
 #ifdef CONFIG_IRQ_FORCED_THREADING
-__read_mostly bool force_irqthreads;
+__read_mostly bool force_irqthreads = IS_ENABLED(CONFIG_IRQ_FORCED_THREADING_DEFAULT);
 
 static int __init setup_forced_irqthreads(char *arg)
 {
 	force_irqthreads = true;
 	return 0;
 }
+static int __init setup_no_irqthreads(char *arg)
+{
+	force_irqthreads = false;
+	return 0;
+}
 early_param("threadirqs", setup_forced_irqthreads);
+early_param("nothreadirqs", setup_no_irqthreads);
 #endif
 
 static void __synchronize_hardirq(struct irq_desc *desc)