linux-kernel - [PATCH v8 5/5] input: pwm-beeper: handle module unloading properly

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Date:   Thu, 26 Jan 2023 10:18:25 +0100
From:   Manuel Traut <manuel.traut@...com>
To:     linux-kernel@...r.kernel.org
Cc:     Manuel Traut <manuel.traut@...com>,
        Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Frieder Schrempf <frieder.schrempf@...tron.de>,
        linux-input@...r.kernel.org, devicetree@...r.kernel.org
Subject: [PATCH v8 5/5] input: pwm-beeper: handle module unloading properly

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

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

Therefore remove device attributes on module unloading and in case
registration at the input subsystem fails.

Signed-off-by: Manuel Traut <manuel.traut@...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 82b05f7f4c70..736b89bd1b42 100644
--- a/drivers/input/misc/pwm-beeper.c
+++ b/drivers/input/misc/pwm-beeper.c
@@ -299,6 +299,7 @@ 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;
 	}
@@ -308,6 +309,17 @@ 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);
@@ -353,6 +365,7 @@ 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