Commit c1c2a15c authored Jun 21, 2022 by Uwe Kleine-König Committed by Bartosz Golaszewski Jun 23, 2022

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>

parent 9ca766ea

drivers/gpio/gpio-grgpio.c

+1 −13

Original line number	Diff line number	Diff line
		@@ -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[] = {