[PATCH v2 2/7] gpio: mockup: tweak gpio_mockup_event_write()

[Bartosz Golaszewski]

Invert the logic of the irq_enabled check and only access the private
data after the input is sanitized.

Signed-off-by: Bartosz Golaszewski <b...@bgdev.pl>
---
 drivers/gpio/gpio-mockup.c | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/drivers/gpio/gpio-mockup.c b/drivers/gpio/gpio-mockup.c
index da76267..d78e8e0 100644
--- a/drivers/gpio/gpio-mockup.c
+++ b/drivers/gpio/gpio-mockup.c
@@ -210,24 +210,23 @@ static ssize_t gpio_mockup_event_write(struct file *file,
        struct gpio_chip *gc;
        int rv, val;
 
-       sfile = file->private_data;
-       priv = sfile->private;
-       desc = priv->desc;
-       chip = priv->chip;
-       gc = &chip->gc;
-
        rv = kstrtoint_from_user(usr_buf, size, 0, &val);
        if (rv)
                return rv;
        if (val != 0 && val != 1)
                return -EINVAL;
 
-       if (!chip->lines[priv->offset].irq_enabled)
-               return size;
+       sfile = file->private_data;
+       priv = sfile->private;
+       desc = priv->desc;
+       chip = priv->chip;
+       gc = &chip->gc;
 
-       gpiod_set_value_cansleep(desc, val);
-       priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
-       irq_work_queue(&priv->chip->irq_ctx.work);
+       if (chip->lines[priv->offset].irq_enabled) {
+               gpiod_set_value_cansleep(desc, val);
+               priv->chip->irq_ctx.irq = gc->irq_base + priv->offset;
+               irq_work_queue(&priv->chip->irq_ctx.work);
+       }
 
        return size;
 }
-- 
2.9.3