linux-kernel - [PATCH 06/17] Input: imx_keypad - use guard notation when acquiring mutex

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Message-ID: <20240825051627.2848495-7-dmitry.torokhov@gmail.com>
Date: Sat, 24 Aug 2024 22:16:10 -0700
From: Dmitry Torokhov <dmitry.torokhov@...il.com>
To: linux-input@...r.kernel.org
Cc: Michael Hennerich <michael.hennerich@...log.com>,
	Shawn Guo <shawnguo@...nel.org>,
	Sascha Hauer <s.hauer@...gutronix.de>,
	Fabio Estevam <festevam@...il.com>,
	Laxman Dewangan <ldewangan@...dia.com>,
	Thierry Reding <thierry.reding@...il.com>,
	Hans de Goede <hdegoede@...hat.com>,
	Tony Lindgren <tony@...mide.com>,
	Jeff LaBundy <jeff@...undy.com>,
	linux-kernel@...r.kernel.org,
	imx@...ts.linux.dev,
	linux-arm-kernel@...ts.infradead.org,
	linux-tegra@...r.kernel.org
Subject: [PATCH 06/17] Input: imx_keypad - use guard notation when acquiring mutex

This 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/keyboard/imx_keypad.c | 27 +++++++++++----------------
 1 file changed, 11 insertions(+), 16 deletions(-)

diff --git a/drivers/input/keyboard/imx_keypad.c b/drivers/input/keyboard/imx_keypad.c
index e15a93619e82..b92268ddfd84 100644
--- a/drivers/input/keyboard/imx_keypad.c
+++ b/drivers/input/keyboard/imx_keypad.c
@@ -521,13 +521,11 @@ static int __maybe_unused imx_kbd_noirq_suspend(struct device *dev)
 	struct input_dev *input_dev = kbd->input_dev;
 	unsigned short reg_val = readw(kbd->mmio_base + KPSR);
 
-	/* imx kbd can wake up system even clock is disabled */
-	mutex_lock(&input_dev->mutex);
-
-	if (input_device_enabled(input_dev))
-		clk_disable_unprepare(kbd->clk);
-
-	mutex_unlock(&input_dev->mutex);
+	scoped_guard(mutex, &input_dev->mutex) {
+		/* imx kbd can wake up system even clock is disabled */
+		if (input_device_enabled(input_dev))
+			clk_disable_unprepare(kbd->clk);
+	}
 
 	if (device_may_wakeup(&pdev->dev)) {
 		if (reg_val & KBD_STAT_KPKD)
@@ -547,23 +545,20 @@ static int __maybe_unused imx_kbd_noirq_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct imx_keypad *kbd = platform_get_drvdata(pdev);
 	struct input_dev *input_dev = kbd->input_dev;
-	int ret = 0;
+	int error;
 
 	if (device_may_wakeup(&pdev->dev))
 		disable_irq_wake(kbd->irq);
 
-	mutex_lock(&input_dev->mutex);
+	guard(mutex)(&input_dev->mutex);
 
 	if (input_device_enabled(input_dev)) {
-		ret = clk_prepare_enable(kbd->clk);
-		if (ret)
-			goto err_clk;
+		error = clk_prepare_enable(kbd->clk);
+		if (error)
+			return error;
 	}
 
-err_clk:
-	mutex_unlock(&input_dev->mutex);
-
-	return ret;
+	return 0;
 }
 
 static const struct dev_pm_ops imx_kbd_pm_ops = {
-- 
2.46.0.295.g3b9ea8a38a-goog