[ARM] 3348/1: Disable GPIO interrupts

Patch from Andrew Victor

disable_irq() lazily disables the interrupt, so the IRQ is only disabled
once the interrupt occurs again.  The GPIO interrupt handler therefore
must first check disable_depth to see if the IRQ needs to be disabled.

Orignal patch by Bill Gatliff.

Signed-off-by: Andrew Victor <andrew@sanpeople.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 12 insertions, 2 deletions

diff --git a/arch/arm/mach-at91rm9200/gpio.c b/arch/arm/mach-at91rm9200/gpio.c
index a9f718bf8ba8..0e396feec468 100644
--- a/arch/arm/mach-at91rm9200/gpio.c
+++ b/arch/arm/mach-at91rm9200/gpio.c
@@ -274,8 +274,18 @@ static void gpio_irq_handler(unsigned irq, struct irqdesc *desc, struct pt_regs
                 gpio = &irq_desc[pin];
 
                 while (isr) {
-                        if (isr & 1)
-                                gpio->handle(pin, gpio, regs);
+                        if (isr & 1) {
+                                if (unlikely(gpio->disable_depth)) {
+                                        /*
+                                         * The core ARM interrupt handler lazily disables IRQs so
+                                         * another IRQ must be generated before it actually gets
+                                         * here to be disabled on the GPIO controller.
+                                         */
+                                        gpio_irq_mask(pin);
+                                }
+                                else
+                                        gpio->handle(pin, gpio, regs);
+                        }
                         pin++;
                         gpio++;
                         isr >>= 1;