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>

diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c
index bccba406fc22c87ce924c9d54855e7314ea6eec2..201b757ad0dbe387e6332e3f88b4c3a85ad1a5c5 100644 (file)
--- 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);
        }