linux-kernel - [PATCH 10/17] Input: lpc32xx-keys - use guard notation when acquiring mutex

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Message-ID: <20240825051627.2848495-11-dmitry.torokhov@gmail.com>
Date: Sat, 24 Aug 2024 22:16:14 -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 10/17] Input: lpc32xx-keys - 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/lpc32xx-keys.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/drivers/input/keyboard/lpc32xx-keys.c b/drivers/input/keyboard/lpc32xx-keys.c
index 423035be86fb..2392e7ec3b19 100644
--- a/drivers/input/keyboard/lpc32xx-keys.c
+++ b/drivers/input/keyboard/lpc32xx-keys.c
@@ -262,7 +262,7 @@ static int lpc32xx_kscan_suspend(struct device *dev)
 	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 	struct input_dev *input = kscandat->input;
 
-	mutex_lock(&input->mutex);
+	guard(mutex)(&input->mutex);
 
 	if (input_device_enabled(input)) {
 		/* Clear IRQ and disable clock */
@@ -270,7 +270,6 @@ static int lpc32xx_kscan_suspend(struct device *dev)
 		clk_disable_unprepare(kscandat->clk);
 	}
 
-	mutex_unlock(&input->mutex);
 	return 0;
 }
 
@@ -279,19 +278,20 @@ static int lpc32xx_kscan_resume(struct device *dev)
 	struct platform_device *pdev = to_platform_device(dev);
 	struct lpc32xx_kscan_drv *kscandat = platform_get_drvdata(pdev);
 	struct input_dev *input = kscandat->input;
-	int retval = 0;
+	int error;
 
-	mutex_lock(&input->mutex);
+	guard(mutex)(&input->mutex);
 
 	if (input_device_enabled(input)) {
 		/* Enable clock and clear IRQ */
-		retval = clk_prepare_enable(kscandat->clk);
-		if (retval == 0)
-			writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
+		error = clk_prepare_enable(kscandat->clk);
+		if (error)
+			return error;
+
+		writel(1, LPC32XX_KS_IRQ(kscandat->kscan_base));
 	}
 
-	mutex_unlock(&input->mutex);
-	return retval;
+	return 0;
 }
 
 static DEFINE_SIMPLE_DEV_PM_OPS(lpc32xx_kscan_pm_ops, lpc32xx_kscan_suspend,
-- 
2.46.0.295.g3b9ea8a38a-goog