[PATCH] cdx: Convert to platform remove callback returning void

[PATCH] cdx: Convert to platform remove callback returning void

[Uwe Kleine-König]

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/cdx/controller/cdx_controller.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/cdx/controller/cdx_controller.c b/drivers/cdx/controller/cdx_controller.c
index 85fe4b1c4e5e..9e99baf43db1 100644
--- a/drivers/cdx/controller/cdx_controller.c
+++ b/drivers/cdx/controller/cdx_controller.c
@@ -198,7 +198,7 @@ static int xlnx_cdx_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int xlnx_cdx_remove(struct platform_device *pdev)
+static void xlnx_cdx_remove(struct platform_device *pdev)
 {
 	struct cdx_controller *cdx = platform_get_drvdata(pdev);
 	struct cdx_mcdi *cdx_mcdi = cdx->priv;
@@ -209,8 +209,6 @@ static int xlnx_cdx_remove(struct platform_device *pdev)
 
 	cdx_mcdi_finish(cdx_mcdi);
 	kfree(cdx_mcdi);
-
-	return 0;
 }
 
 static const struct of_device_id cdx_match_table[] = {
@@ -227,7 +225,7 @@ static struct platform_driver cdx_pdriver = {
 		   .of_match_table = cdx_match_table,
 		   },
 	.probe = xlnx_cdx_probe,
-	.remove = xlnx_cdx_remove,
+	.remove_new = xlnx_cdx_remove,
 };
 
 static int __init cdx_controller_init(void)

base-commit: 8ffc8b1bbd505e27e2c8439d326b6059c906c9dd
-- 
2.43.0

Re: [PATCH] cdx: Convert to platform remove callback returning void

[Gupta, Nipun]

On 3/8/2024 2:21 PM, 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>

Acked-by: Nipun Gupta <nipun.gupta@amd.com>

Re: [PATCH] cdx: Convert to platform remove callback returning void

[Uwe Kleine-König]

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Hello Greg,

On Fri, Mar 08, 2024 at 09:51:05AM +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>

we just talked in irc about this thread that might have fell through the
cracks on your side.

Thanks for reconsidering to apply it for v6.10-rc1,
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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Re: [PATCH] cdx: Convert to platform remove callback returning void

[Greg Kroah-Hartman]

On Sat, Apr 13, 2024 at 12:12:56PM +0200, Uwe Kleine-König wrote:
> Hello Greg,
> 
> On Fri, Mar 08, 2024 at 09:51:05AM +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>
> 
> we just talked in irc about this thread that might have fell through the
> cracks on your side.
> 
> Thanks for reconsidering to apply it for v6.10-rc1,

Now applied, thanks.

greg k-h