[06/12] bus: sun50i-de2: Convert to platform remove callback returning void

Message ID 20231109202830.4124591-7-u.kleine-koenig@pengutronix.de
State New
Headers
Series bus: Convert to platform remove callback returning void |

Commit Message

Uwe Kleine-König Nov. 9, 2023, 8:28 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/bus/sun50i-de2.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)
  

Comments

Andre Przywara Nov. 10, 2023, 10:18 a.m. UTC | #1
On Thu,  9 Nov 2023 21:28:36 +0100
Uwe Kleine-König <u.kleine-koenig@pengutronix.de> wrote:

Hi,

> 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: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
>  drivers/bus/sun50i-de2.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/bus/sun50i-de2.c b/drivers/bus/sun50i-de2.c
> index 414f29cdedf0..3339311ce068 100644
> --- a/drivers/bus/sun50i-de2.c
> +++ b/drivers/bus/sun50i-de2.c
> @@ -24,10 +24,9 @@ static int sun50i_de2_bus_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int sun50i_de2_bus_remove(struct platform_device *pdev)
> +static void sun50i_de2_bus_remove(struct platform_device *pdev)
>  {
>  	sunxi_sram_release(&pdev->dev);
> -	return 0;
>  }
>  
>  static const struct of_device_id sun50i_de2_bus_of_match[] = {
> @@ -37,7 +36,7 @@ static const struct of_device_id sun50i_de2_bus_of_match[] = {
>  
>  static struct platform_driver sun50i_de2_bus_driver = {
>  	.probe = sun50i_de2_bus_probe,
> -	.remove = sun50i_de2_bus_remove,
> +	.remove_new = sun50i_de2_bus_remove,
>  	.driver = {
>  		.name = "sun50i-de2-bus",
>  		.of_match_table = sun50i_de2_bus_of_match,
  
Jernej Škrabec Nov. 18, 2023, 9:50 p.m. UTC | #2
Dne četrtek, 09. november 2023 ob 21:28:36 CET je Uwe Kleine-König napisal(a):
> 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: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

> ---
>  drivers/bus/sun50i-de2.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/bus/sun50i-de2.c b/drivers/bus/sun50i-de2.c
> index 414f29cdedf0..3339311ce068 100644
> --- a/drivers/bus/sun50i-de2.c
> +++ b/drivers/bus/sun50i-de2.c
> @@ -24,10 +24,9 @@ static int sun50i_de2_bus_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> -static int sun50i_de2_bus_remove(struct platform_device *pdev)
> +static void sun50i_de2_bus_remove(struct platform_device *pdev)
>  {
>  	sunxi_sram_release(&pdev->dev);
> -	return 0;
>  }
>  
>  static const struct of_device_id sun50i_de2_bus_of_match[] = {
> @@ -37,7 +36,7 @@ static const struct of_device_id sun50i_de2_bus_of_match[] = {
>  
>  static struct platform_driver sun50i_de2_bus_driver = {
>  	.probe = sun50i_de2_bus_probe,
> -	.remove = sun50i_de2_bus_remove,
> +	.remove_new = sun50i_de2_bus_remove,
>  	.driver = {
>  		.name = "sun50i-de2-bus",
>  		.of_match_table = sun50i_de2_bus_of_match,
>
  

Patch

diff --git a/drivers/bus/sun50i-de2.c b/drivers/bus/sun50i-de2.c
index 414f29cdedf0..3339311ce068 100644
--- a/drivers/bus/sun50i-de2.c
+++ b/drivers/bus/sun50i-de2.c
@@ -24,10 +24,9 @@  static int sun50i_de2_bus_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int sun50i_de2_bus_remove(struct platform_device *pdev)
+static void sun50i_de2_bus_remove(struct platform_device *pdev)
 {
 	sunxi_sram_release(&pdev->dev);
-	return 0;
 }
 
 static const struct of_device_id sun50i_de2_bus_of_match[] = {
@@ -37,7 +36,7 @@  static const struct of_device_id sun50i_de2_bus_of_match[] = {
 
 static struct platform_driver sun50i_de2_bus_driver = {
 	.probe = sun50i_de2_bus_probe,
-	.remove = sun50i_de2_bus_remove,
+	.remove_new = sun50i_de2_bus_remove,
 	.driver = {
 		.name = "sun50i-de2-bus",
 		.of_match_table = sun50i_de2_bus_of_match,