gpio: grgpio: Fix device removing

If a platform device's remove callback returns non-zero, the device core
emits a warning and still removes the device and calls the devm cleanup
callbacks.

So it's not save to not unregister the gpiochip because on the next request
to a GPIO the driver accesses kfree()'d memory. Also if an IRQ triggers,
the freed memory is accessed.

Instead rely on the GPIO framework to ensure that after gpiochip_remove()
all GPIOs are freed and so the corresponding IRQs are unmapped.

This is a preparation for making platform remove callbacks return void.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>

diff --git a/drivers/gpio/gpio-grgpio.c b/drivers/gpio/gpio-grgpio.c
index df56361..bea0e32 100644 (file)
--- a/drivers/gpio/gpio-grgpio.c
+++ b/drivers/gpio/gpio-grgpio.c
@@ -434,25 +434,13 @@ static int grgpio_probe(struct platform_device *ofdev)
 static int grgpio_remove(struct platform_device *ofdev)
 {
        struct grgpio_priv *priv = platform_get_drvdata(ofdev);
-       int i;
-       int ret = 0;
-
-       if (priv->domain) {
-               for (i = 0; i < GRGPIO_MAX_NGPIO; i++) {
-                       if (priv->uirqs[i].refcnt != 0) {
-                               ret = -EBUSY;
-                               goto out;
-                       }
-               }
-       }
 
        gpiochip_remove(&priv->gc);
 
        if (priv->domain)
                irq_domain_remove(priv->domain);
 
-out:
-       return ret;
+       return 0;
 }
 
 static const struct of_device_id grgpio_match[] = {