linux-kernel - [PATCH 12/22] Input: iqs269a - use guard notation when acquiring mutex

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Message-ID: <20240904044756.1047629-1-dmitry.torokhov@gmail.com>
Date: Tue,  3 Sep 2024 21:47:55 -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 12/22] Input: iqs269a - 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/iqs269a.c | 46 +++++++++++++-----------------------
 1 file changed, 16 insertions(+), 30 deletions(-)

diff --git a/drivers/input/misc/iqs269a.c b/drivers/input/misc/iqs269a.c
index 843f8a3f3410..c34d847fa4af 100644
--- a/drivers/input/misc/iqs269a.c
+++ b/drivers/input/misc/iqs269a.c
@@ -365,7 +365,7 @@ static int iqs269_ati_mode_set(struct iqs269_private *iqs269,
 	if (mode > IQS269_CHx_ENG_A_ATI_MODE_MAX)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	engine_a = be16_to_cpu(ch_reg[ch_num].engine_a);
 
@@ -375,8 +375,6 @@ static int iqs269_ati_mode_set(struct iqs269_private *iqs269,
 	ch_reg[ch_num].engine_a = cpu_to_be16(engine_a);
 	iqs269->ati_current = false;
 
-	mutex_unlock(&iqs269->lock);
-
 	return 0;
 }
 
@@ -389,9 +387,9 @@ static int iqs269_ati_mode_get(struct iqs269_private *iqs269,
 	if (ch_num >= IQS269_NUM_CH)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
+
 	engine_a = be16_to_cpu(ch_reg[ch_num].engine_a);
-	mutex_unlock(&iqs269->lock);
 
 	engine_a &= IQS269_CHx_ENG_A_ATI_MODE_MASK;
 	*mode = (engine_a >> IQS269_CHx_ENG_A_ATI_MODE_SHIFT);
@@ -429,7 +427,7 @@ static int iqs269_ati_base_set(struct iqs269_private *iqs269,
 		return -EINVAL;
 	}
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 
@@ -439,8 +437,6 @@ static int iqs269_ati_base_set(struct iqs269_private *iqs269,
 	ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
 	iqs269->ati_current = false;
 
-	mutex_unlock(&iqs269->lock);
-
 	return 0;
 }
 
@@ -453,9 +449,9 @@ static int iqs269_ati_base_get(struct iqs269_private *iqs269,
 	if (ch_num >= IQS269_NUM_CH)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
+
 	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
-	mutex_unlock(&iqs269->lock);
 
 	switch (engine_b & IQS269_CHx_ENG_B_ATI_BASE_MASK) {
 	case IQS269_CHx_ENG_B_ATI_BASE_75:
@@ -491,7 +487,7 @@ static int iqs269_ati_target_set(struct iqs269_private *iqs269,
 	if (target > IQS269_CHx_ENG_B_ATI_TARGET_MAX)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 
@@ -501,8 +497,6 @@ static int iqs269_ati_target_set(struct iqs269_private *iqs269,
 	ch_reg[ch_num].engine_b = cpu_to_be16(engine_b);
 	iqs269->ati_current = false;
 
-	mutex_unlock(&iqs269->lock);
-
 	return 0;
 }
 
@@ -515,10 +509,9 @@ static int iqs269_ati_target_get(struct iqs269_private *iqs269,
 	if (ch_num >= IQS269_NUM_CH)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
-	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
-	mutex_unlock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
+	engine_b = be16_to_cpu(ch_reg[ch_num].engine_b);
 	*target = (engine_b & IQS269_CHx_ENG_B_ATI_TARGET_MASK) * 32;
 
 	return 0;
@@ -1199,7 +1192,7 @@ static int iqs269_dev_init(struct iqs269_private *iqs269)
 {
 	int error;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	/*
 	 * Early revisions of silicon require the following workaround in order
@@ -1210,19 +1203,19 @@ static int iqs269_dev_init(struct iqs269_private *iqs269)
 		error = regmap_multi_reg_write(iqs269->regmap, iqs269_tws_init,
 					       ARRAY_SIZE(iqs269_tws_init));
 		if (error)
-			goto err_mutex;
+			return error;
 	}
 
 	error = regmap_update_bits(iqs269->regmap, IQS269_HALL_UI,
 				   IQS269_HALL_UI_ENABLE,
 				   iqs269->hall_enable ? ~0 : 0);
 	if (error)
-		goto err_mutex;
+		return error;
 
 	error = regmap_raw_write(iqs269->regmap, IQS269_SYS_SETTINGS,
 				 &iqs269->sys_reg, sizeof(iqs269->sys_reg));
 	if (error)
-		goto err_mutex;
+		return error;
 
 	/*
 	 * The following delay gives the device time to deassert its RDY output
@@ -1232,10 +1225,7 @@ static int iqs269_dev_init(struct iqs269_private *iqs269)
 
 	iqs269->ati_current = true;
 
-err_mutex:
-	mutex_unlock(&iqs269->lock);
-
-	return error;
+	return 0;
 }
 
 static int iqs269_input_init(struct iqs269_private *iqs269)
@@ -1580,13 +1570,11 @@ static ssize_t hall_enable_store(struct device *dev,
 	if (error)
 		return error;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	iqs269->hall_enable = val;
 	iqs269->ati_current = false;
 
-	mutex_unlock(&iqs269->lock);
-
 	return count;
 }
 
@@ -1643,13 +1631,11 @@ static ssize_t rx_enable_store(struct device *dev,
 	if (val > 0xFF)
 		return -EINVAL;
 
-	mutex_lock(&iqs269->lock);
+	guard(mutex)(&iqs269->lock);
 
 	ch_reg[iqs269->ch_num].rx_enable = val;
 	iqs269->ati_current = false;
 
-	mutex_unlock(&iqs269->lock);
-
 	return count;
 }
 
-- 
2.46.0.469.g59c65b2a67-goog