[PATCH 0/2] counter: Convert to platform remove callback returning void

[PATCH 0/2] counter: Convert to platform remove callback returning void

[Uwe Kleine-König]

Hello,

this series converts all platform drivers below drivers/counter to stop
using struct platform_driver::remove(). See commit 5c5a7680e67b
("platform: Provide a remove callback that returns no value") for an
extended explanation and the eventual goal.

Both conversations are trivial, because the driver's .remove() callbacks
returned zero unconditionally.

There are no interdependencies between these patches, still I'd expect
them to be picked up together.

Best regards
Uwe

Uwe Kleine-König (2):
  counter: ti-ecap-capture: Convert to platform remove callback
    returning void
  counter: ti-eqep: Convert to platform remove callback returning void

 drivers/counter/ti-ecap-capture.c | 6 ++----
 drivers/counter/ti-eqep.c         | 6 ++----
 2 files changed, 4 insertions(+), 8 deletions(-)

base-commit: 8ffc8b1bbd505e27e2c8439d326b6059c906c9dd
-- 
2.43.0

[PATCH 1/2] counter: ti-ecap-capture: 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/counter/ti-ecap-capture.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/counter/ti-ecap-capture.c b/drivers/counter/ti-ecap-capture.c
index fb1cb1774674..d33d35055b91 100644
--- a/drivers/counter/ti-ecap-capture.c
+++ b/drivers/counter/ti-ecap-capture.c
@@ -537,15 +537,13 @@ static int ecap_cnt_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int ecap_cnt_remove(struct platform_device *pdev)
+static void ecap_cnt_remove(struct platform_device *pdev)
 {
 	struct counter_device *counter_dev = platform_get_drvdata(pdev);
 	struct ecap_cnt_dev *ecap_dev = counter_priv(counter_dev);
 
 	if (ecap_dev->enabled)
 		ecap_cnt_capture_disable(counter_dev);
-
-	return 0;
 }
 
 static int ecap_cnt_suspend(struct device *dev)
@@ -600,7 +598,7 @@ MODULE_DEVICE_TABLE(of, ecap_cnt_of_match);
 
 static struct platform_driver ecap_cnt_driver = {
 	.probe = ecap_cnt_probe,
-	.remove = ecap_cnt_remove,
+	.remove_new = ecap_cnt_remove,
 	.driver = {
 		.name = "ecap-capture",
 		.of_match_table = ecap_cnt_of_match,
-- 
2.43.0

[PATCH 2/2] counter: ti-eqep: 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/counter/ti-eqep.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/counter/ti-eqep.c b/drivers/counter/ti-eqep.c
index b0f24cf3e891..072b11fd6b32 100644
--- a/drivers/counter/ti-eqep.c
+++ b/drivers/counter/ti-eqep.c
@@ -425,7 +425,7 @@ static int ti_eqep_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static int ti_eqep_remove(struct platform_device *pdev)
+static void ti_eqep_remove(struct platform_device *pdev)
 {
 	struct counter_device *counter = platform_get_drvdata(pdev);
 	struct device *dev = &pdev->dev;
@@ -433,8 +433,6 @@ static int ti_eqep_remove(struct platform_device *pdev)
 	counter_unregister(counter);
 	pm_runtime_put_sync(dev);
 	pm_runtime_disable(dev);
-
-	return 0;
 }
 
 static const struct of_device_id ti_eqep_of_match[] = {
@@ -445,7 +443,7 @@ MODULE_DEVICE_TABLE(of, ti_eqep_of_match);
 
 static struct platform_driver ti_eqep_driver = {
 	.probe = ti_eqep_probe,
-	.remove = ti_eqep_remove,
+	.remove_new = ti_eqep_remove,
 	.driver = {
 		.name = "ti-eqep-cnt",
 		.of_match_table = ti_eqep_of_match,
-- 
2.43.0

Re: [PATCH 2/2] counter: ti-eqep: Convert to platform remove callback returning void

[David Lechner]

On 3/10/24 3:06 AM, 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: David Lechner <david@lechnology.com>

Re: [PATCH 0/2] counter: Convert to platform remove callback returning void

[wbg]

From: William Breathitt Gray <wbg@kernel.org>


On Sun, 10 Mar 2024 09:06:05 +0100, Uwe Kleine-König wrote:
> this series converts all platform drivers below drivers/counter to stop
> using struct platform_driver::remove(). See commit 5c5a7680e67b
> ("platform: Provide a remove callback that returns no value") for an
> extended explanation and the eventual goal.
> 
> Both conversations are trivial, because the driver's .remove() callbacks
> returned zero unconditionally.
> 
> [...]

Applied, thanks!

[1/2] counter: ti-ecap-capture: Convert to platform remove callback returning void
      commit: bcc8ced4e1713bc7fa19a422321756788a58512f
[2/2] counter: ti-eqep: Convert to platform remove callback returning void
      commit: eca588187f9129300c6e44d64b819545cede463d

Best regards,
-- 
William Breathitt Gray <wbg@kernel.org>