diff mbox series

[3/5] watchdog: at91sam9_wdt: Convert to platform remove callback returning void

Message ID 20231106154807.3866712-4-u.kleine-koenig@pengutronix.de (mailing list archive)
State New, archived
Headers show
Series watchdog: Drop platform_driver_probe() and convert to platform remove callback returning void (part II) | expand

Commit Message

Uwe Kleine-König Nov. 6, 2023, 3:48 p.m. UTC
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---
 drivers/watchdog/at91sam9_wdt.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

Comments

Guenter Roeck Nov. 6, 2023, 4:02 p.m. UTC | #1
On Mon, Nov 06, 2023 at 04:48:11PM +0100, Uwe Kleine-König wrote:
> The .remove() callback for a platform driver returns an int which makes
> many driver authors wrongly assume it's possible to do error handling by
> returning an error code. However the value returned is ignored (apart
> from emitting a warning) and this typically results in resource leaks.
> 
> To improve here there is a quest to make the remove callback return
> void. In the first step of this quest all drivers are converted to
> .remove_new(), which already returns void. Eventually after all drivers
> are converted, .remove_new() will be renamed to .remove().
> 
> Trivially convert this driver from always returning zero in the remove
> callback to the void returning variant.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Nicolas Ferre Nov. 7, 2023, 9:20 a.m. UTC | #2
On 06/11/2023 at 16:48, Uwe Kleine-König wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
> 
> The .remove() callback for a platform driver returns an int which makes
> many driver authors wrongly assume it's possible to do error handling by
> returning an error code. However the value returned is ignored (apart
> from emitting a warning) and this typically results in resource leaks.
> 
> To improve here there is a quest to make the remove callback return
> void. In the first step of this quest all drivers are converted to
> .remove_new(), which already returns void. Eventually after all drivers
> are converted, .remove_new() will be renamed to .remove().
> 
> Trivially convert this driver from always returning zero in the remove
> callback to the void returning variant.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>

Thanks Uwe!

Best regards,
   Nicolas

> ---
>   drivers/watchdog/at91sam9_wdt.c | 6 ++----
>   1 file changed, 2 insertions(+), 4 deletions(-)

[..]
diff mbox series

Patch

diff --git a/drivers/watchdog/at91sam9_wdt.c b/drivers/watchdog/at91sam9_wdt.c
index 507adb12754d..2c6474cb858b 100644
--- a/drivers/watchdog/at91sam9_wdt.c
+++ b/drivers/watchdog/at91sam9_wdt.c
@@ -372,15 +372,13 @@  static int at91wdt_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int at91wdt_remove(struct platform_device *pdev)
+static void at91wdt_remove(struct platform_device *pdev)
 {
 	struct at91wdt *wdt = platform_get_drvdata(pdev);
 	watchdog_unregister_device(&wdt->wdd);
 
 	pr_warn("I quit now, hardware will probably reboot!\n");
 	del_timer(&wdt->timer);
-
-	return 0;
 }
 
 #if defined(CONFIG_OF)
@@ -394,7 +392,7 @@  MODULE_DEVICE_TABLE(of, at91_wdt_dt_ids);
 
 static struct platform_driver at91wdt_driver = {
 	.probe		= at91wdt_probe,
-	.remove		= at91wdt_remove,
+	.remove_new	= at91wdt_remove,
 	.driver		= {
 		.name	= "at91_wdt",
 		.of_match_table = of_match_ptr(at91_wdt_dt_ids),