[ARM] 3690/1: genirq: Introduce and make use of dummy irq chip
Patch from Thomas Gleixner
From: Thomas Gleixner <tglx@linutronix.de>
ARM has a couple of really dumb interrupt controllers.
Implement a generic one and fixup the ARM migration. ARM reused
the no_irq_chip for this purpose, but this does not work out
for platforms which are not converted to the new interrupt
type handling model.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c
index 4a0952d9..54105bd 100644
--- a/kernel/irq/chip.c
+++ b/kernel/irq/chip.c
@@ -462,9 +462,18 @@
if (!handle)
handle = handle_bad_irq;
- if (is_chained && desc->chip == &no_irq_chip)
- printk(KERN_WARNING "Trying to install "
- "chained interrupt type for IRQ%d\n", irq);
+ if (desc->chip == &no_irq_chip) {
+ printk(KERN_WARNING "Trying to install %sinterrupt handler "
+ "for IRQ%d\n", is_chained ? "chained " : " ", irq);
+ /*
+ * Some ARM implementations install a handler for really dumb
+ * interrupt hardware without setting an irq_chip. This worked
+ * with the ARM no_irq_chip but the check in setup_irq would
+ * prevent us to setup the interrupt at all. Switch it to
+ * dummy_irq_chip for easy transition.
+ */
+ desc->chip = &dummy_irq_chip;
+ }
spin_lock_irqsave(&desc->lock, flags);
