diff mbox series

[v2] media: staging: media: starfive: camss: Convert to platform remove callback returning void

Message ID 20240411072836.221625-2-u.kleine-koenig@pengutronix.de
State Accepted
Commit b1f3677aebe5a9352a02b40465e71313f91cbd12
Headers show
Series [v2] media: staging: media: starfive: camss: Convert to platform remove callback returning void | expand

Commit Message

Uwe Kleine-König April 11, 2024, 7:28 a.m. UTC
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>
---
Hello,

(implicit) v1: https://lore.kernel.org/linux-staging/c43a9c68e64e3e8360174ae0c6706e46d3d40a11.1709886922.git.u.kleine-koenig@pengutronix.de
    
Changes since (implicit) v1:

 - Drop doc about return value in kerneldoc, thanks to Changhuang Liang
   for noticing

Best regards
Uwe

 drivers/staging/media/starfive/camss/stf-camss.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)


base-commit: 4118d9533ff3a5d16efb476a0d00afceecd92cf5

Comments

Changhuang Liang April 12, 2024, 7 a.m. UTC | #1
> media: staging: media: starfive: camss: 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.
> 
> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>

Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>

But it seems that v1 is already merge.

Regards,
Changhuang
Uwe Kleine-König April 12, 2024, 7:08 a.m. UTC | #2
Hello,

On Fri, Apr 12, 2024 at 07:00:22AM +0000, Changhuang Liang wrote:
> > media: staging: media: starfive: camss: 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.
> > 
> > Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
> 
> Reviewed-by: Changhuang Liang <changhuang.liang@starfivetech.com>
> 
> But it seems that v1 is already merge.

Hmm, it's not in next though. IMHO it would be a good idea to add the
tree that has my patch staged to next.

Best regards
Uwe
diff mbox series

Patch

diff --git a/drivers/staging/media/starfive/camss/stf-camss.c b/drivers/staging/media/starfive/camss/stf-camss.c
index a587f860101a..4ea40671b44d 100644
--- a/drivers/staging/media/starfive/camss/stf-camss.c
+++ b/drivers/staging/media/starfive/camss/stf-camss.c
@@ -352,10 +352,8 @@  static int stfcamss_probe(struct platform_device *pdev)
 /*
  * stfcamss_remove - Remove STFCAMSS platform device
  * @pdev: Pointer to STFCAMSS platform device
- *
- * Always returns 0.
  */
-static int stfcamss_remove(struct platform_device *pdev)
+static void stfcamss_remove(struct platform_device *pdev)
 {
 	struct stfcamss *stfcamss = platform_get_drvdata(pdev);
 
@@ -364,8 +362,6 @@  static int stfcamss_remove(struct platform_device *pdev)
 	media_device_cleanup(&stfcamss->media_dev);
 	v4l2_async_nf_cleanup(&stfcamss->notifier);
 	pm_runtime_disable(&pdev->dev);
-
-	return 0;
 }
 
 static const struct of_device_id stfcamss_of_match[] = {
@@ -420,7 +416,7 @@  static const struct dev_pm_ops stfcamss_pm_ops = {
 
 static struct platform_driver stfcamss_driver = {
 	.probe = stfcamss_probe,
-	.remove = stfcamss_remove,
+	.remove_new = stfcamss_remove,
 	.driver = {
 		.name = "starfive-camss",
 		.pm = &stfcamss_pm_ops,