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| author | Linus Walleij <linus.walleij@linaro.org> | 2016-06-15 22:57:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-06-24 10:22:06 -0700 |
| commit | c6ad700afe337609d7d0ee37be0e469f08e86a1a (patch) | |
| tree | 6accdb44ab3de73fddfed759fb67b06e04744615 | |
| parent | a5b62e5e2089996dc87189ea605f9f16e8920528 (diff) | |
| download | lwn-c6ad700afe337609d7d0ee37be0e469f08e86a1a.tar.gz lwn-c6ad700afe337609d7d0ee37be0e469f08e86a1a.zip | |
gpio: make sure gpiod_to_irq() returns negative on NULL desc
commit 79bb71bd1d93197ce227fa167b450b633f30a52b upstream.
commit 54d77198fdfbc4f0fe11b4252c1d9c97d51a3264
("gpio: bail out silently on NULL descriptors")
doesn't work for gpiod_to_irq(): drivers assume that NULL
descriptors will give negative IRQ numbers in return.
It has been pointed out that returning 0 is NO_IRQ and that
drivers should be amended to treat this as an error, but that
is for the longer term: now let us repair the semantics.
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Reported-by: Hans de Goede <hdegoede@redhat.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/gpio/gpiolib.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 719d1114f8eb..cf3e71243d6d 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2006,7 +2006,14 @@ int gpiod_to_irq(const struct gpio_desc *desc) struct gpio_chip *chip; int offset; - VALIDATE_DESC(desc); + /* + * Cannot VALIDATE_DESC() here as gpiod_to_irq() consumer semantics + * requires this function to not return zero on an invalid descriptor + * but rather a negative error number. + */ + if (!desc || !desc->gdev || !desc->gdev->chip) + return -EINVAL; + chip = desc->gdev->chip; offset = gpio_chip_hwgpio(desc); return chip->to_irq ? chip->to_irq(chip, offset) : -ENXIO; |