[PATCH] powerpc/512x: lpbfifo: 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().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <redacted>
---
 arch/powerpc/platforms/512x/mpc512x_lpbfifo.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
index 1bfb29574caa..dbe722f7b855 100644
--- a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
+++ b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c

@@ -477,7 +477,7 @@ static int mpc512x_lpbfifo_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int mpc512x_lpbfifo_remove(struct platform_device *pdev)
+static void pc512x_lpbfifo_remove(struct platform_device *pdev)
 {
 	unsigned long flags;
 	struct dma_device *dma_dev = lpbfifo.chan->device;

@@ -494,8 +494,6 @@ static int mpc512x_lpbfifo_remove(struct platform_device *pdev)
 	free_irq(lpbfifo.irq, &pdev->dev);
 	irq_dispose_mapping(lpbfifo.irq);
 	dma_release_channel(lpbfifo.chan);
-
-	return 0;
 }
 
 static const struct of_device_id mpc512x_lpbfifo_match[] = {

@@ -506,7 +504,7 @@ MODULE_DEVICE_TABLE(of, mpc512x_lpbfifo_match);
 
 static struct platform_driver mpc512x_lpbfifo_driver = {
 	.probe = mpc512x_lpbfifo_probe,
-	.remove = mpc512x_lpbfifo_remove,
+	.remove_new = mpc512x_lpbfifo_remove,
 	.driver = {
 		.name = DRV_NAME,
 		.of_match_table = mpc512x_lpbfifo_match,

base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
-- 
2.39.2

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().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <redacted>
---
Changes since (implicit) v1:

 - provide an actually compilable patch :-\

Best regards
Uwe

 arch/powerpc/platforms/512x/mpc512x_lpbfifo.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
index 1bfb29574caa..c1e981649bd9 100644
--- a/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c
+++ b/arch/powerpc/platforms/512x/mpc512x_lpbfifo.c

@@ -477,7 +477,7 @@ static int mpc512x_lpbfifo_probe(struct platform_device *pdev)
 	return ret;
 }
 
-static int mpc512x_lpbfifo_remove(struct platform_device *pdev)
+static void mpc512x_lpbfifo_remove(struct platform_device *pdev)
 {
 	unsigned long flags;
 	struct dma_device *dma_dev = lpbfifo.chan->device;

@@ -494,8 +494,6 @@ static int mpc512x_lpbfifo_remove(struct platform_device *pdev)
 	free_irq(lpbfifo.irq, &pdev->dev);
 	irq_dispose_mapping(lpbfifo.irq);
 	dma_release_channel(lpbfifo.chan);
-
-	return 0;
 }
 
 static const struct of_device_id mpc512x_lpbfifo_match[] = {

@@ -506,7 +504,7 @@ MODULE_DEVICE_TABLE(of, mpc512x_lpbfifo_match);
 
 static struct platform_driver mpc512x_lpbfifo_driver = {
 	.probe = mpc512x_lpbfifo_probe,
-	.remove = mpc512x_lpbfifo_remove,
+	.remove_new = mpc512x_lpbfifo_remove,
 	.driver = {
 		.name = DRV_NAME,
 		.of_match_table = mpc512x_lpbfifo_match,

base-commit: 06c2afb862f9da8dc5efa4b6076a0e48c3fbaaa5
-- 
2.39.2

On Tue, 11 Jul 2023 16:31:45 +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() is renamed to .remove().

[...]

Applied to powerpc/fixes.

[1/1] powerpc/512x: lpbfifo: Convert to platform remove callback returning void
      https://git.kernel.org/powerpc/c/8739312ed2faa79df61d157ac44fda840646d444

cheers