On 08/30/2013 04:46 PM, Linus Walleij wrote:
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.
Acked-by: Alexandre Courbot <[email protected]>
Suggested-by: Alexandre Courbot <[email protected]>
Cc: Frank Rowand <[email protected]>
Cc: Tim Bird <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
---
drivers/gpio/gpiolib.c | 36 ++++++++++++++++++++++--------------
1 file changed, 22 insertions(+), 14 deletions(-)
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d6413b2..f041f9e 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;
@@ -1765,7 +1771,7 @@ 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;
}
@@ -1773,8 +1779,10 @@ static int gpiod_set_debounce(struct gpio_desc *desc,
unsigned debounce)
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__);
+ }
status = gpio_ensure_requested(desc);
if (status < 0)
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