linux-kernel - [PATCH 08/22] Input: drv2665 - use guard notation when acquiring mutex

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Message-ID: <20240904044244.1042174-9-dmitry.torokhov@gmail.com>
Date: Tue,  3 Sep 2024 21:42:28 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: linux-input@...r.kernel.org
Cc: Michael Hennerich <michael.hennerich@...log.com>,
	Ville Syrjala <syrjala@....fi>,
	Support Opensource <support.opensource@...semi.com>,
	Eddie James <eajames@...ux.ibm.com>,
	Andrey Moiseev <o2g.org.ru@...il.com>,
	Hans de Goede <hdegoede@...hat.com>,
	Javier Carrasco <javier.carrasco.cruz@...il.com>,
	Jeff LaBundy <jeff@...undy.com>,
	linux-kernel@...r.kernel.org
Subject: [PATCH 08/22] Input: drv2665 - use guard notation when acquiring mutex

Using guard notation makes the code more compact and error handling
more robust by ensuring that mutexes are released in all code paths
when control leaves critical section.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@...il.com>
---
 drivers/input/misc/drv2665.c | 44 +++++++++++++++++-------------------
 1 file changed, 21 insertions(+), 23 deletions(-)

diff --git a/drivers/input/misc/drv2665.c b/drivers/input/misc/drv2665.c
index f98e4d765307..77ec96c7db76 100644
--- a/drivers/input/misc/drv2665.c
+++ b/drivers/input/misc/drv2665.c
@@ -225,59 +225,57 @@ static int drv2665_probe(struct i2c_client *client)
 static int drv2665_suspend(struct device *dev)
 {
 	struct drv2665_data *haptics = dev_get_drvdata(dev);
-	int ret = 0;
+	int error;
 
-	mutex_lock(&haptics->input_dev->mutex);
+	guard(mutex)(&haptics->input_dev->mutex);
 
 	if (input_device_enabled(haptics->input_dev)) {
-		ret = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
-					 DRV2665_STANDBY, DRV2665_STANDBY);
-		if (ret) {
+		error = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
+					   DRV2665_STANDBY, DRV2665_STANDBY);
+		if (error) {
 			dev_err(dev, "Failed to set standby mode\n");
 			regulator_disable(haptics->regulator);
-			goto out;
+			return error;
 		}
 
-		ret = regulator_disable(haptics->regulator);
-		if (ret) {
+		error = regulator_disable(haptics->regulator);
+		if (error) {
 			dev_err(dev, "Failed to disable regulator\n");
 			regmap_update_bits(haptics->regmap,
 					   DRV2665_CTRL_2,
 					   DRV2665_STANDBY, 0);
+			return error;
 		}
 	}
-out:
-	mutex_unlock(&haptics->input_dev->mutex);
-	return ret;
+
+	return 0;
 }
 
 static int drv2665_resume(struct device *dev)
 {
 	struct drv2665_data *haptics = dev_get_drvdata(dev);
-	int ret = 0;
+	int error;
 
-	mutex_lock(&haptics->input_dev->mutex);
+	guard(mutex)(&haptics->input_dev->mutex);
 
 	if (input_device_enabled(haptics->input_dev)) {
-		ret = regulator_enable(haptics->regulator);
-		if (ret) {
+		error = regulator_enable(haptics->regulator);
+		if (error) {
 			dev_err(dev, "Failed to enable regulator\n");
-			goto out;
+			return error;
 		}
 
-		ret = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
-					 DRV2665_STANDBY, 0);
-		if (ret) {
+		error = regmap_update_bits(haptics->regmap, DRV2665_CTRL_2,
+					   DRV2665_STANDBY, 0);
+		if (error) {
 			dev_err(dev, "Failed to unset standby mode\n");
 			regulator_disable(haptics->regulator);
-			goto out;
+			return error;
 		}
 
 	}
 
-out:
-	mutex_unlock(&haptics->input_dev->mutex);
-	return ret;
+	return 0;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(drv2665_pm_ops, drv2665_suspend, drv2665_resume);
-- 
2.46.0.469.g59c65b2a67-goog