[ARM] 3378/1: ixp2000: fix gpio interrupt handling

Patch from Lennert Buytenhek

ixp2000 used to initially mark GPIO interrupts as invalid, and not
mark them valid until set_irq_type() was called, but this doesn't
work if you want to use request_irq() with the SA_TRIGGER_* flags.

So, just mark the GPIO interrupts valid from the beginning.  We
configure GPIOs as inputs when set_irq_type() is called anyway, so
this shouldn't be a problem.
Signed-off-by: Lennert Buytenhek <buytenh@wantstofly.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-ixp2000/core.c

@@ -288,8 +288,6 @@ void gpio_line_config(int line, int direction)
 
 	local_irq_save(flags);
 	if (direction == GPIO_OUT) {
-		irq_desc[line + IRQ_IXP2000_GPIO0].valid = 0;
-
 		/* if it's an output, it ain't an interrupt anymore */
 		GPIO_IRQ_falling_edge &= ~(1 << line);
 		GPIO_IRQ_rising_edge &= ~(1 << line);
@@ -351,11 +349,6 @@ static int ixp2000_GPIO_irq_type(unsigned int irq, unsigned int type)
 		GPIO_IRQ_level_high &= ~(1 << line);
 	update_gpio_int_csrs();
 
-	/*
-	 * Finally, mark the corresponding IRQ as valid.
-	 */
-	irq_desc[irq].valid = 1;
-
 	return 0;
 }
 
@@ -506,14 +499,10 @@ void __init ixp2000_init_irq(void)
 	}
 	set_irq_chained_handler(IRQ_IXP2000_ERRSUM, ixp2000_err_irq_handler);
 
-	/*
-	 * GPIO IRQs are invalid until someone sets the interrupt mode
-	 * by calling set_irq_type().
-	 */
 	for (irq = IRQ_IXP2000_GPIO0; irq <= IRQ_IXP2000_GPIO7; irq++) {
 		set_irq_chip(irq, &ixp2000_GPIO_irq_chip);
 		set_irq_handler(irq, do_level_IRQ);
-		set_irq_flags(irq, 0);
+		set_irq_flags(irq, IRQF_VALID);
 	}
 	set_irq_chained_handler(IRQ_IXP2000_GPIO, ixp2000_GPIO_irq_handler);