Re: [PATCH] gpio: Fix test on unsigned in lnw_irq_type()

[Roel Kluin <roel.kluin@gmail.com>]

The wrong test was used, gpio is unsigned. Also lnw->chip.ngpio is
set to 64, so if gpio equals that, then reg (= gpio / 32) becomes 2,
an index out of bounds for GRER and GFER that have 2 elements.

Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
>>>> From: Andrew Morton [mailto:akpm@linux-foundation.org]
>>>>> -    if (gpio < 0 || gpio > lnw->chip.ngpio)
>>>>> +    if (gpio > lnw->chip.ngpio)
>>>>>              return -EINVAL;
>>>>
>>>> Should that be >= ?

> Oh, my bad. Andrew is right, should be >=...

Ok, how about this then?

diff --git a/drivers/gpio/langwell_gpio.c b/drivers/gpio/langwell_gpio.c
index 5711ce5..72af3fc 100644
--- a/drivers/gpio/langwell_gpio.c
+++ b/drivers/gpio/langwell_gpio.c
@@ -123,7 +123,7 @@ static int lnw_irq_type(unsigned irq, unsigned type)
 	void __iomem *grer = (void __iomem *)(&lnw->reg_base->GRER[reg]);
 	void __iomem *gfer = (void __iomem *)(&lnw->reg_base->GFER[reg]);
 
-	if (gpio < 0 || gpio > lnw->chip.ngpio)
+	if (gpio >= lnw->chip.ngpio)
 		return -EINVAL;
 	spin_lock_irqsave(&lnw->lock, flags);
 	if (type & IRQ_TYPE_EDGE_RISING)