[PATCH 5/5 v7] input: pwm-beeper: handle module unloading properly

[PATCH 5/5 v7] input: pwm-beeper: handle module unloading properly

[Manuel Traut]

'input: pwm-beeper: add feature to set volume via sysfs' adds device
attributes without removing them on error or if the module is unloaded.

This change removes the device attributes on module unloading or if
registering on the input subsystem fails.

If the module will be unloaded and loaded again it fails:
[ 1007.918180] sysfs: cannot create duplicate filename '/devices/platform/buzzer/volume'

Signed-off-by: Manuel Traut <manuel.traut@mt.com>
---
 drivers/input/misc/pwm-beeper.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
index fe543c4151d6..8ef2937e8f21 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -300,6 +300,7 @@ static int pwm_beeper_probe(struct platform_device *pdev)
 
 	error = input_register_device(beeper->input);
 	if (error) {
+		sysfs_remove_group(&pdev->dev.kobj, &pwm_beeper_attribute_group);
 		dev_err(dev, "Failed to register input device: %d\n", error);
 		return error;
 	}
@@ -309,6 +310,17 @@ static int pwm_beeper_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static int pwm_beeper_remove(struct platform_device *pdev)
+{
+	struct pwm_beeper *beeper;
+
+    beeper = platform_get_drvdata(pdev);
+	input_unregister_device(beeper->input);
+	sysfs_remove_group(&pdev->dev.kobj, &pwm_beeper_attribute_group);
+
+	return 0;
+}
+
 static int __maybe_unused pwm_beeper_suspend(struct device *dev)
 {
 	struct pwm_beeper *beeper = dev_get_drvdata(dev);
@@ -354,6 +366,7 @@ MODULE_DEVICE_TABLE(of, pwm_beeper_match);
 
 static struct platform_driver pwm_beeper_driver = {
 	.probe	= pwm_beeper_probe,
+	.remove	= pwm_beeper_remove,
 	.driver = {
 		.name	= "pwm-beeper",
 		.pm	= &pwm_beeper_pm_ops,
-- 
2.39.0

Re: [PATCH 5/5 v7] input: pwm-beeper: handle module unloading properly

[Krzysztof Kozlowski]

On 24/01/2023 17:44, Manuel Traut wrote:
> 'input: pwm-beeper: add feature to set volume via sysfs' adds device
> attributes without removing them on error or if the module is unloaded.
> 
> This change removes the device attributes on module unloading or if

Do not use "This commit/patch".
https://elixir.bootlin.com/linux/v5.17.1/source/Documentation/process/submitting-patches.rst#L95

> registering on the input subsystem fails.
> 
> If the module will be unloaded and loaded again it fails:
> [ 1007.918180] sysfs: cannot create duplicate filename '/devices/platform/buzzer/volume'
> 
> Signed-off-by: Manuel Traut <manuel.traut@mt.com>
> ---
>  drivers/input/misc/pwm-beeper.c | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/drivers/input/misc/pwm-beeper.c b/drivers/input/misc/pwm-beeper.c
> index fe543c4151d6..8ef2937e8f21 100644
> --- a/drivers/input/misc/pwm-beeper.c
> +++ b/drivers/input/misc/pwm-beeper.c
> @@ -300,6 +300,7 @@ static int pwm_beeper_probe(struct platform_device *pdev)
>  
>  	error = input_register_device(beeper->input);
>  	if (error) {
> +		sysfs_remove_group(&pdev->dev.kobj, &pwm_beeper_attribute_group);
>  		dev_err(dev, "Failed to register input device: %d\n", error);
>  		return error;
>  	}
> @@ -309,6 +310,17 @@ static int pwm_beeper_probe(struct platform_device *pdev)
>  	return 0;
>  }
>  
> +static int pwm_beeper_remove(struct platform_device *pdev)
> +{
> +	struct pwm_beeper *beeper;
> +
> +    beeper = platform_get_drvdata(pdev);

Wrong indentation.

Please run scripts/checkpatch.pl and fix reported warnings.


> +	input_unregister_device(beeper->input);

Best regards,
Krzysztof