[PATCH] genirq: add IRQ_NOAUTOEN support

Enable platforms to disable the automatic enabling of freshly set up irqs.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

3 files changed, 13 insertions, 7 deletions

diff --git a/include/linux/irq.h b/include/linux/irq.h
index 1df49ec7f820..14d7e94048dd 100644
--- a/include/linux/irq.h
+++ b/include/linux/irq.h
@@ -42,6 +42,7 @@
 
 #define IRQ_NOPROBE     512     /* IRQ is not valid for probing */
 #define IRQ_NOREQUEST   1024    /* IRQ cannot be requested */
+#define IRQ_NOAUTOEN    2048    /* IRQ will not be enabled on request irq */
 /**
  * struct hw_interrupt_type - hardware interrupt type descriptor
  *
diff --git a/kernel/irq/handle.c b/kernel/irq/handle.c
index 402fa3aec1e4..9b398d52f1b7 100644
--- a/kernel/irq/handle.c
+++ b/kernel/irq/handle.c
@@ -32,6 +32,7 @@ struct irq_desc irq_desc[NR_IRQS] __cacheline_aligned = {
         [0 ... NR_IRQS-1] = {
                 .status = IRQ_DISABLED,
                 .chip = &no_irq_type,
+                .depth = 1,
                 .lock = SPIN_LOCK_UNLOCKED,
 #ifdef CONFIG_SMP
                 .affinity = CPU_MASK_ALL
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index cae900a849c4..9ea18879fb62 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -216,13 +216,17 @@ int setup_irq(unsigned int irq, struct irqaction *new)
                 desc->status |= IRQ_PER_CPU;
 #endif
         if (!shared) {
-                desc->depth = 0;
-                desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT |
-                                  IRQ_WAITING | IRQ_INPROGRESS);
-                if (desc->chip->startup)
-                        desc->chip->startup(irq);
-                else
-                        desc->chip->enable(irq);
+                desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING |
+                                  IRQ_INPROGRESS);
+
+                if (!(desc->status & IRQ_NOAUTOEN)) {
+                        desc->depth = 0;
+                        desc->status &= ~IRQ_DISABLED;
+                        if (desc->chip->startup)
+                                desc->chip->startup(irq);
+                        else
+                                desc->chip->enable(irq);
+                }
         }
         spin_unlock_irqrestore(&desc->lock, flags);