2024-04-23 07:12:57

by Uwe Kleine-König

[permalink] [raw]
Subject: [PATCH] clk: imx: imx8mp: 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.

Fixes: 1496dd413b2e ("clk: imx: imx8mp: Add pm_runtime support for power saving")
Signed-off-by: Uwe Kleine-König <[email protected]>
---
Hello,

after the merge window leading to v6.10-rc1 (assuming Linus has >= 10 fingers
this cycle :-) I want to switch the prototype of struct
platform_driver::remove to return void. So please either merge this
patch together with 1496dd413b2e, or accept me sending this patch
together with the patch changing the function's prototype for inclusion
to Greg's driver-core tree.

Thanks
Uwe

drivers/clk/imx/clk-imx8mp-audiomix.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/clk/imx/clk-imx8mp-audiomix.c b/drivers/clk/imx/clk-imx8mp-audiomix.c
index 574a032309c1..be9df93b6adb 100644
--- a/drivers/clk/imx/clk-imx8mp-audiomix.c
+++ b/drivers/clk/imx/clk-imx8mp-audiomix.c
@@ -346,11 +346,9 @@ static int clk_imx8mp_audiomix_probe(struct platform_device *pdev)
return ret;
}

-static int clk_imx8mp_audiomix_remove(struct platform_device *pdev)
+static void clk_imx8mp_audiomix_remove(struct platform_device *pdev)
{
pm_runtime_disable(&pdev->dev);
-
- return 0;
}

static int clk_imx8mp_audiomix_runtime_suspend(struct device *dev)
@@ -382,7 +380,7 @@ MODULE_DEVICE_TABLE(of, clk_imx8mp_audiomix_of_match);

static struct platform_driver clk_imx8mp_audiomix_driver = {
.probe = clk_imx8mp_audiomix_probe,
- .remove = clk_imx8mp_audiomix_remove,
+ .remove_new = clk_imx8mp_audiomix_remove,
.driver = {
.name = "imx8mp-audio-blk-ctrl",
.of_match_table = clk_imx8mp_audiomix_of_match,
--
2.43.0



2024-05-01 11:39:51

by Abel Vesa

[permalink] [raw]
Subject: Re: [PATCH] clk: imx: imx8mp: Convert to platform remove callback returning void

On 24-04-23 09:12:31, 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.
>
> Fixes: 1496dd413b2e ("clk: imx: imx8mp: Add pm_runtime support for power saving")
> Signed-off-by: Uwe Kleine-K?nig <[email protected]>

LGTM.

Reviewed-by: Abel Vesa <[email protected]>

> ---
> Hello,
>
> after the merge window leading to v6.10-rc1 (assuming Linus has >= 10 fingers
> this cycle :-) I want to switch the prototype of struct
> platform_driver::remove to return void. So please either merge this
> patch together with 1496dd413b2e, or accept me sending this patch
> together with the patch changing the function's prototype for inclusion
> to Greg's driver-core tree.

Sure, will apply it today.

>
> Thanks
> Uwe
>
> drivers/clk/imx/clk-imx8mp-audiomix.c | 6 ++----
> 1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/clk/imx/clk-imx8mp-audiomix.c b/drivers/clk/imx/clk-imx8mp-audiomix.c
> index 574a032309c1..be9df93b6adb 100644
> --- a/drivers/clk/imx/clk-imx8mp-audiomix.c
> +++ b/drivers/clk/imx/clk-imx8mp-audiomix.c
> @@ -346,11 +346,9 @@ static int clk_imx8mp_audiomix_probe(struct platform_device *pdev)
> return ret;
> }
>
> -static int clk_imx8mp_audiomix_remove(struct platform_device *pdev)
> +static void clk_imx8mp_audiomix_remove(struct platform_device *pdev)
> {
> pm_runtime_disable(&pdev->dev);
> -
> - return 0;
> }
>
> static int clk_imx8mp_audiomix_runtime_suspend(struct device *dev)
> @@ -382,7 +380,7 @@ MODULE_DEVICE_TABLE(of, clk_imx8mp_audiomix_of_match);
>
> static struct platform_driver clk_imx8mp_audiomix_driver = {
> .probe = clk_imx8mp_audiomix_probe,
> - .remove = clk_imx8mp_audiomix_remove,
> + .remove_new = clk_imx8mp_audiomix_remove,
> .driver = {
> .name = "imx8mp-audio-blk-ctrl",
> .of_match_table = clk_imx8mp_audiomix_of_match,
> --
> 2.43.0
>

2024-05-01 11:54:49

by Abel Vesa

[permalink] [raw]
Subject: Re: [PATCH] clk: imx: imx8mp: Convert to platform remove callback returning void


On Tue, 23 Apr 2024 09:12:31 +0200, 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().
>
> [...]

Applied, thanks!

[1/1] clk: imx: imx8mp: Convert to platform remove callback returning void
commit: f5072cffb35c122ec85d91ef327fa8814f04297b

Best regards,
--
Abel Vesa <[email protected]>