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| author | Linus Walleij <linus.walleij@linaro.org> | 2016-02-11 10:28:44 +0100 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2016-02-11 20:29:46 +0100 |
| commit | 33a68e86fd7741f782c71a0daa9111b352e94445 (patch) | |
| tree | 96e6ee9894a0513d98e43300dd17bec0a45e36a4 /drivers/gpio/gpiolib.c | |
| parent | fdeb8e1547cb9dd39d5d7223b33f3565cf86c28e (diff) | |
| download | op-kernel-dev-33a68e86fd7741f782c71a0daa9111b352e94445.zip op-kernel-dev-33a68e86fd7741f782c71a0daa9111b352e94445.tar.gz | |
gpio: reference count the gpio device for each desc
Every time a descriptor is retrieved from the gpiolib, we issue
module_get() to reference count the module supplying the GPIOs.
We also need to call device_get() and device_put() as we also
reference the backing gpio_device when doing this.
Since the sysfs GPIO interface is using gpiod_get() this will
also reference count the sysfs requests until all GPIOs are
unexported.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Diffstat (limited to 'drivers/gpio/gpiolib.c')
| -rw-r--r-- | drivers/gpio/gpiolib.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 0738f9a..646dea4 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1205,6 +1205,8 @@ int gpiod_request(struct gpio_desc *desc, const char *label) status = __gpiod_request(desc, label); if (status < 0) module_put(gdev->owner); + else + get_device(&gdev->dev); } if (status) @@ -1248,10 +1250,12 @@ static bool __gpiod_free(struct gpio_desc *desc) void gpiod_free(struct gpio_desc *desc) { - if (desc && __gpiod_free(desc)) + if (desc && desc->gdev && __gpiod_free(desc)) { module_put(desc->gdev->owner); - else + put_device(&desc->gdev->dev); + } else { WARN_ON(extra_checks); + } } /** |
