gpio: sysfs: only call irq helper if needed

Only call irq helper if actually reconfiguring interrupt state.

This is a preparatory step in introducing separate gpio-irq request and
free functions.

Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 14 insertions, 5 deletions

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index bccba406fc22..201b757ad0db 100644
--- a/drivers/gpio/gpiolib-sysfs.c
+++ b/drivers/gpio/gpiolib-sysfs.c
@@ -139,9 +139,6 @@ static int gpio_setup_irq(struct device *dev, unsigned long gpio_flags)
         unsigned long           irq_flags;
         int                     ret, irq;
 
-        if ((desc->flags & GPIO_TRIGGER_MASK) == gpio_flags)
-                return 0;
-
         irq = gpiod_to_irq(desc);
         if (irq < 0)
                 return -EIO;
@@ -240,6 +237,9 @@ static ssize_t edge_show(struct device *dev,
 static ssize_t edge_store(struct device *dev,
                 struct device_attribute *attr, const char *buf, size_t size)
 {
+        struct gpiod_data *data = dev_get_drvdata(dev);
+        struct gpio_desc *desc = data->desc;
+        unsigned long flags;
         ssize_t                 status;
         int                     i;
 
@@ -249,12 +249,20 @@ static ssize_t edge_store(struct device *dev,
         return -EINVAL;
 
 found:
+        flags = trigger_types[i].flags;
+
         mutex_lock(&sysfs_lock);
 
-        status = gpio_setup_irq(dev, trigger_types[i].flags);
+        if ((desc->flags & GPIO_TRIGGER_MASK) == flags) {
+                status = size;
+                goto out_unlock;
+        }
+
+        status = gpio_setup_irq(dev, flags);
         if (!status)
                 status = size;
 
+out_unlock:
         mutex_unlock(&sysfs_lock);
 
         return status;
@@ -690,7 +698,8 @@ void gpiod_unexport(struct gpio_desc *desc)
                  * Release irq after deregistration to prevent race with
                  * edge_store.
                  */
-                gpio_setup_irq(dev, 0);
+                if (desc->flags & GPIO_TRIGGER_MASK)
+                        gpio_setup_irq(dev, 0);
                 put_device(dev);
                 kfree(data);
         }