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authorLinus Walleij <linus.walleij@linaro.org>2016-06-15 22:57:38 +0200
committerLinus Walleij <linus.walleij@linaro.org>2016-06-17 18:12:07 +0200
commit79bb71bd1d93197ce227fa167b450b633f30a52b (patch)
treebf2edaee0bd70d92406b10e15d82ef80ea248389
parent053ae6499a5634c0dc5fa18437e1af3d2f2ec98e (diff)
downloadlinux-79bb71bd1d93197ce227fa167b450b633f30a52b.tar.bz2
gpio: make sure gpiod_to_irq() returns negative on NULL desc
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>
-rw-r--r--drivers/gpio/gpiolib.c9
1 files changed, 8 insertions, 1 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 58d822d7e8da..f39bf05993e7 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2056,7 +2056,14 @@ 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);
if (chip->to_irq) {