linux-kernel - [PATCH] misc: tps6594-esm: Convert to platform remove callback returning void

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Date:   Mon, 10 Jul 2023 10:23:11 +0200
From:   Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
To:     Arnd Bergmann <arnd@...db.de>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     kernel@...gutronix.de, linux-kernel@...r.kernel.org
Subject: [PATCH] misc: tps6594-esm: 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() is renamed to .remove().

There are two calls that can go wrong in tps6594_esm_remove(); for both
there is already an error message. Not returning the error code has the
only side effect of suppressing (another) error message by the core
about the error being ignored. So tps6594_esm_remove() can be converted
to return void without any loss.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@...gutronix.de>
---
 drivers/misc/tps6594-esm.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/tps6594-esm.c b/drivers/misc/tps6594-esm.c
index b488f704f104..a32da1c4ba61 100644
--- a/drivers/misc/tps6594-esm.c
+++ b/drivers/misc/tps6594-esm.c
@@ -65,7 +65,7 @@ static int tps6594_esm_probe(struct platform_device *pdev)
 	return 0;
 }

-static int tps6594_esm_remove(struct platform_device *pdev)
+static void tps6594_esm_remove(struct platform_device *pdev)
 {
 	struct tps6594 *tps = dev_get_drvdata(pdev->dev.parent);
 	struct device *dev = &pdev->dev;
@@ -86,8 +86,6 @@ static int tps6594_esm_remove(struct platform_device *pdev)
 out:
 	pm_runtime_put_sync(dev);
 	pm_runtime_disable(dev);
-
-	return ret;
 }

 static int tps6594_esm_suspend(struct device *dev)
@@ -121,7 +119,7 @@ static struct platform_driver tps6594_esm_driver = {
 		.pm = pm_sleep_ptr(&tps6594_esm_pm_ops),
 	},
 	.probe = tps6594_esm_probe,
-	.remove = tps6594_esm_remove,
+	.remove_new = tps6594_esm_remove,
 };

 module_platform_driver(tps6594_esm_driver);

base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
-- 
2.39.2