target/linux/generic/patches-2.6.25/964-backport_gpiolib_fix_off_by_one_errors.patch

   1 From: Trent Piepho <xyzzy@speakeasy.org>
   2 Date: Fri, 23 May 2008 20:04:44 +0000 (-0700)
   3 Subject: gpiolib: fix off by one errors
   4 X-Git-Tag: v2.6.26-rc4~31
   5 X-Git-Url: http://git.kernel.org/?p=linux%2Fkernel%2Fgit%2Ftorvalds%2Flinux-2.6.git;a=commitdiff_plain;h=bff5fda972dc23bd1806a47c2098ae173585d013
   6
   7 gpiolib: fix off by one errors
   8
   9 The last gpio belonging to a chip is chip->base + chip->ngpios - 1.  Some
  10 places in the code, but not all, forgot the critical minus one.
  11
  12 Signed-off-by: Trent Piepho <xyzzy@speakeasy.org>
  13 Acked-by: David Brownell <dbrownell@users.sourceforge.net>
  14 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
  15 Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
  16 ---
  17
  18 --- a/drivers/gpio/gpiolib.c
  19 +++ b/drivers/gpio/gpiolib.c
  20 @@ -127,7 +127,7 @@ int __init gpiochip_reserve(int start, i
  21         unsigned long flags;
  22         int i;
  23
  24 -       if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio))
  25 +       if (!gpio_is_valid(start) || !gpio_is_valid(start + ngpio - 1))
  26                 return -EINVAL;
  27
  28         spin_lock_irqsave(&gpio_lock, flags);
  29 @@ -170,7 +170,7 @@ int gpiochip_add(struct gpio_chip *chip)
  30         unsigned        id;
  31         int             base = chip->base;
  32
  33 -       if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio))
  34 +       if ((!gpio_is_valid(base) || !gpio_is_valid(base + chip->ngpio - 1))
  35                         && base >= 0) {
  36                 status = -EINVAL;
  37                 goto fail;
  38 @@ -207,7 +207,7 @@ fail:
  39         /* failures here can mean systems won't boot... */
  40         if (status)
  41                 pr_err("gpiochip_add: gpios %d..%d (%s) not registered\n",
  42 -                       chip->base, chip->base + chip->ngpio,
  43 +                       chip->base, chip->base + chip->ngpio - 1,
  44                         chip->label ? : "generic");
  45         return status;
  46  }