[PATCH] gpiolib: Fix off by one errors

From: Trent Piepho
Date: Tue May 20 2008 - 14:03:20 EST


The last gpio belonging to a chip is chip->base + chip->ngpios - 1. Some
places in the code, but not all, forgot the critical minus one.

Signed-off-by: Trent Piepho <xyzzy@xxxxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 6 +++---
1 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 7f138c6..beaf6b3 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -127,7 +127,7 @@ int __init gpiochip_reserve(int start, int ngpio)
unsigned long flags;
int i;

- if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio))
+ if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1))
return -EINVAL;

spin_lock_irqsave(&gpio_lock, flags);
@@ -170,7 +170,7 @@ int gpiochip_add(struct gpio_chip *chip)
unsigned id;
int base = chip->base;

- if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio))
+ if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
&& base >= 0) {
status = -EINVAL;
goto fail;
@@ -207,7 +207,7 @@ fail:
/* failures here can mean systems won't boot... */
if (status)
pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n",
- chip->base, chip->base + chip->ngpio,
+ chip->base, chip->base + chip->ngpio - 1,
chip->label ? : "generic");
return status;
}
--
1.5.4.1

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