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-rw-r--r--drivers/gpio/gpiolib.c15
-rw-r--r--include/asm-generic/gpio.h2
2 files changed, 14 insertions, 3 deletions
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index d8db2f8e..eb75d12e 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -68,6 +68,9 @@ static void gpio_ensure_requested(struct gpio_desc *desc)
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
pr_warning("GPIO-%d autorequested\n", (int)(desc - gpio_desc));
desc_set_label(desc, "[auto]");
+ if (!try_module_get(desc->chip->owner))
+ pr_err("GPIO-%d: module can't be gotten \n",
+ (int)(desc - gpio_desc));
}
}
@@ -177,6 +180,9 @@ int gpio_request(unsigned gpio, const char *label)
if (desc->chip == NULL)
goto done;
+ if (!try_module_get(desc->chip->owner))
+ goto done;
+
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled.
*/
@@ -184,8 +190,10 @@ int gpio_request(unsigned gpio, const char *label)
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags) == 0) {
desc_set_label(desc, label ? : "?");
status = 0;
- } else
+ } else {
status = -EBUSY;
+ module_put(desc->chip->owner);
+ }
done:
if (status)
@@ -209,9 +217,10 @@ void gpio_free(unsigned gpio)
spin_lock_irqsave(&gpio_lock, flags);
desc = &gpio_desc[gpio];
- if (desc->chip && test_and_clear_bit(FLAG_REQUESTED, &desc->flags))
+ if (desc->chip && test_and_clear_bit(FLAG_REQUESTED, &desc->flags)) {
desc_set_label(desc, NULL);
- else
+ module_put(desc->chip->owner);
+ } else
WARN_ON(extra_checks);
spin_unlock_irqrestore(&gpio_lock, flags);
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index f29a502..7e77b6f 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -17,6 +17,7 @@
#endif
struct seq_file;
+struct module;
/**
* struct gpio_chip - abstract a GPIO controller
@@ -48,6 +49,7 @@ struct seq_file;
*/
struct gpio_chip {
char *label;
+ struct module *owner;
int (*direction_input)(struct gpio_chip *chip,
unsigned offset);
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