diff options
| author | Linus Walleij <linus.walleij@linaro.org> | 2013-08-30 09:41:45 +0200 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2013-09-03 14:08:28 +0200 |
| commit | be1a4b13089b1e18da83a549d49163ccad3c19ba (patch) | |
| tree | 321f0e432ef3df8f7ea17a664087e58d3f24a7c6 | |
| parent | 6c17aa0138a6c55364936bbaa35846e09a4db53b (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>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 41 |
1 files changed, 25 insertions, 16 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index d6413b2e084..0cbdddab4ff 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) |