2023-09-25 10:05:59

by Uwe Kleine-König

Subject: [PATCH 12/40] soc/litex: litex_soc_ctrl: Convert to platform remove callback returning void

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 <[email protected]>
---
drivers/soc/litex/litex_soc_ctrl.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c
index f75790091d38..10813299aa10 100644
--- a/drivers/soc/litex/litex_soc_ctrl.c
+++ b/drivers/soc/litex/litex_soc_ctrl.c
@@ -120,12 +120,11 @@ static int litex_soc_ctrl_probe(struct platform_device *pdev)
return 0;
}

-static int litex_soc_ctrl_remove(struct platform_device *pdev)
+static void litex_soc_ctrl_remove(struct platform_device *pdev)
{
struct litex_soc_ctrl_device *soc_ctrl_dev = platform_get_drvdata(pdev);

unregister_restart_handler(&soc_ctrl_dev->reset_nb);
- return 0;
}

static struct platform_driver litex_soc_ctrl_driver = {
@@ -134,7 +133,7 @@ static struct platform_driver litex_soc_ctrl_driver = {
.of_match_table = of_match_ptr(litex_soc_ctrl_of_match)
},
.probe = litex_soc_ctrl_probe,
- .remove = litex_soc_ctrl_remove,
+ .remove_new = litex_soc_ctrl_remove,
};

module_platform_driver(litex_soc_ctrl_driver);
--
2.40.1

2023-09-25 16:24:43

by Gabriel L. Somlo

Subject: Re: [PATCH 12/40] soc/litex: litex_soc_ctrl: Convert to platform remove callback returning void

On Mon, Sep 25, 2023 at 11:55:03AM +0200, Uwe Kleine-K?nig 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-K?nig <[email protected]>

Thanks!
Acked-by: Gabriel Somlo <[email protected]>

> ---
> drivers/soc/litex/litex_soc_ctrl.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/soc/litex/litex_soc_ctrl.c b/drivers/soc/litex/litex_soc_ctrl.c
> index f75790091d38..10813299aa10 100644
> --- a/drivers/soc/litex/litex_soc_ctrl.c
> +++ b/drivers/soc/litex/litex_soc_ctrl.c
> @@ -120,12 +120,11 @@ static int litex_soc_ctrl_probe(struct platform_device *pdev)
> return 0;
> }
>
> -static int litex_soc_ctrl_remove(struct platform_device *pdev)
> +static void litex_soc_ctrl_remove(struct platform_device *pdev)
> {
> struct litex_soc_ctrl_device *soc_ctrl_dev = platform_get_drvdata(pdev);
>
> unregister_restart_handler(&soc_ctrl_dev->reset_nb);
> - return 0;
> }
>
> static struct platform_driver litex_soc_ctrl_driver = {
> @@ -134,7 +133,7 @@ static struct platform_driver litex_soc_ctrl_driver = {
> .of_match_table = of_match_ptr(litex_soc_ctrl_of_match)
> },
> .probe = litex_soc_ctrl_probe,
> - .remove = litex_soc_ctrl_remove,
> + .remove_new = litex_soc_ctrl_remove,
> };
>
> module_platform_driver(litex_soc_ctrl_driver);
> --
> 2.40.1
>