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authorLinus Walleij <linus.walleij@linaro.org>2013-08-30 09:41:45 +0200
committerLinus Walleij <linus.walleij@linaro.org>2013-09-03 14:08:28 +0200
commitbe1a4b13089b1e18da83a549d49163ccad3c19ba (patch)
tree321f0e432ef3df8f7ea17a664087e58d3f24a7c6 /drivers/gpio
parent6c17aa0138a6c55364936bbaa35846e09a4db53b (diff)
gpio: improve error path in gpiolib
At several places the gpiolib will proceed to handle a GPIO descriptor even if it's ->chip member is NULL and no gpiochip is associated. Fix this by checking that both the descriptor cookie *and* the chip pointer are valid. Also bail out earlier with more specific diagnostic messages on missing operations for setting as input/output or debounce. ChangeLog v1->v2: - Also return -EIO on gpiod_set_debounce() with missing operations in the vtable - Fix indentations. Suggested-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Frank Rowand <frank.rowand@sonymobile.com> Cc: Tim Bird <tim.bird@sonymobile.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio')
-rw-r--r--drivers/gpio/gpiolib.c41
1 files changed, 25 insertions, 16 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d6413b2e0844..0cbdddab4ff2 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -1398,7 +1398,7 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
int status = -EPROBE_DEFER;
unsigned long flags;
- if (!desc) {
+ if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1406,8 +1406,6 @@ static int gpiod_request(struct gpio_desc *desc, const char *label)
spin_lock_irqsave(&gpio_lock, flags);
chip = desc->chip;
- if (chip == NULL)
- goto done;
if (!try_module_get(chip->owner))
goto done;
@@ -1630,16 +1628,20 @@ static int gpiod_direction_input(struct gpio_desc *desc)
int status = -EINVAL;
int offset;
- if (!desc) {
+ if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
+ chip = desc->chip;
+ if (!chip->get || !chip->direction_input) {
+ pr_warn("%s: missing get() or direction_input() operations\n",
+ __func__);
+ return -EIO;
+ }
+
spin_lock_irqsave(&gpio_lock, flags);
- chip = desc->chip;
- if (!chip || !chip->get || !chip->direction_input)
- goto fail;
status = gpio_ensure_requested(desc);
if (status < 0)
goto fail;
@@ -1691,7 +1693,7 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
int status = -EINVAL;
int offset;
- if (!desc) {
+ if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
@@ -1704,11 +1706,15 @@ static int gpiod_direction_output(struct gpio_desc *desc, int value)
if (!value && test_bit(FLAG_OPEN_SOURCE, &desc->flags))
return gpiod_direction_input(desc);
+ chip = desc->chip;
+ if (!chip->set || !chip->direction_output) {
+ pr_warn("%s: missing set() or direction_output() operations\n",
+ __func__);
+ return -EIO;
+ }
+
spin_lock_irqsave(&gpio_lock, flags);
- chip = desc->chip;
- if (!chip || !chip->set || !chip->direction_output)
- goto fail;
status = gpio_ensure_requested(desc);
if (status < 0)
goto fail;
@@ -1765,16 +1771,19 @@ static int gpiod_set_debounce(struct gpio_desc *desc, unsigned debounce)
int status = -EINVAL;
int offset;
- if (!desc) {
+ if (!desc || !desc->chip) {
pr_warn("%s: invalid GPIO\n", __func__);
return -EINVAL;
}
- spin_lock_irqsave(&gpio_lock, flags);
-
chip = desc->chip;
- if (!chip || !chip->set || !chip->set_debounce)
- goto fail;
+ if (!chip->set || !chip->set_debounce) {
+ pr_warn("%s: missing set() or set_debounce() operations\n",
+ __func__);
+ return -EIO;
+ }
+
+ spin_lock_irqsave(&gpio_lock, flags);
status = gpio_ensure_requested(desc);
if (status < 0)