linux-kernel - [PATCH 01/17] Input: adp5589-keys - use guard notation when acquiring mutex

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Message-ID: <20240825051627.2848495-2-dmitry.torokhov@gmail.com>
Date: Sat, 24 Aug 2024 22:16:05 -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 01/17] Input: adp5589-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/adp5589-keys.c | 39 +++++++++++++--------------
 1 file changed, 18 insertions(+), 21 deletions(-)

diff --git a/drivers/input/keyboard/adp5589-keys.c b/drivers/input/keyboard/adp5589-keys.c
index 8996e00cd63a..735d96b056d4 100644
--- a/drivers/input/keyboard/adp5589-keys.c
+++ b/drivers/input/keyboard/adp5589-keys.c
@@ -404,7 +404,7 @@ static void adp5589_gpio_set_value(struct gpio_chip *chip,
 	unsigned int bank = kpad->var->bank(kpad->gpiomap[off]);
 	unsigned int bit = kpad->var->bit(kpad->gpiomap[off]);
 
-	mutex_lock(&kpad->gpio_lock);
+	guard(mutex)(&kpad->gpio_lock);
 
 	if (val)
 		kpad->dat_out[bank] |= bit;
@@ -413,8 +413,6 @@ static void adp5589_gpio_set_value(struct gpio_chip *chip,
 
 	adp5589_write(kpad->client, kpad->var->reg(ADP5589_GPO_DATA_OUT_A) +
 		      bank, kpad->dat_out[bank]);
-
-	mutex_unlock(&kpad->gpio_lock);
 }
 
 static int adp5589_gpio_direction_input(struct gpio_chip *chip, unsigned off)
@@ -422,18 +420,13 @@ static int adp5589_gpio_direction_input(struct gpio_chip *chip, unsigned off)
 	struct adp5589_kpad *kpad = gpiochip_get_data(chip);
 	unsigned int bank = kpad->var->bank(kpad->gpiomap[off]);
 	unsigned int bit = kpad->var->bit(kpad->gpiomap[off]);
-	int ret;
 
-	mutex_lock(&kpad->gpio_lock);
+	guard(mutex)(&kpad->gpio_lock);
 
 	kpad->dir[bank] &= ~bit;
-	ret = adp5589_write(kpad->client,
-			    kpad->var->reg(ADP5589_GPIO_DIRECTION_A) + bank,
-			    kpad->dir[bank]);
-
-	mutex_unlock(&kpad->gpio_lock);
-
-	return ret;
+	return adp5589_write(kpad->client,
+			     kpad->var->reg(ADP5589_GPIO_DIRECTION_A) + bank,
+			     kpad->dir[bank]);
 }
 
 static int adp5589_gpio_direction_output(struct gpio_chip *chip,
@@ -442,9 +435,9 @@ static int adp5589_gpio_direction_output(struct gpio_chip *chip,
 	struct adp5589_kpad *kpad = gpiochip_get_data(chip);
 	unsigned int bank = kpad->var->bank(kpad->gpiomap[off]);
 	unsigned int bit = kpad->var->bit(kpad->gpiomap[off]);
-	int ret;
+	int error;
 
-	mutex_lock(&kpad->gpio_lock);
+	guard(mutex)(&kpad->gpio_lock);
 
 	kpad->dir[bank] |= bit;
 
@@ -453,15 +446,19 @@ static int adp5589_gpio_direction_output(struct gpio_chip *chip,
 	else
 		kpad->dat_out[bank] &= ~bit;
 
-	ret = adp5589_write(kpad->client, kpad->var->reg(ADP5589_GPO_DATA_OUT_A)
-			    + bank, kpad->dat_out[bank]);
-	ret |= adp5589_write(kpad->client,
-			     kpad->var->reg(ADP5589_GPIO_DIRECTION_A) + bank,
-			     kpad->dir[bank]);
+	error = adp5589_write(kpad->client,
+			      kpad->var->reg(ADP5589_GPO_DATA_OUT_A) + bank,
+			      kpad->dat_out[bank]);
+	if (error)
+		return error;
 
-	mutex_unlock(&kpad->gpio_lock);
+	error = adp5589_write(kpad->client,
+			      kpad->var->reg(ADP5589_GPIO_DIRECTION_A) + bank,
+			      kpad->dir[bank]);
+	if (error)
+		return error;
 
-	return ret;
+	return 0;
 }
 
 static int adp5589_build_gpiomap(struct adp5589_kpad *kpad,
-- 
2.46.0.295.g3b9ea8a38a-goog