[PATCH 00/29] hwmon: Rely on subsystem locking [set 2]

[PATCH 00/29] hwmon: Rely on subsystem locking [set 2]

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

This is the second set of patches. More will follow.

----------------------------------------------------------------
Guenter Roeck (29):
      hwmon: (max127) Rely on subsystem locking
      hwmon: (lm95234) Rely on subsystem locking
      hwmon: (lm92) Rely on subsystem locking
      hwmon: (hs3001) Rely on subsystem locking
      hwmon: (sbtsi_temp) Rely on subsystem locking
      hwmon: (ina2xx) Rely on subsystem locking
      hwmon: (sht4x) Rely on subsystem locking
      hwmon: (ina3221) Rely on subsystem locking
      hwmon: (k10temp) Rely on subsystem locking
      hwmon: (mr75203) Drop unnecessary include file
      hwmon: (powr1220) Rely on subsystem locking
      hwmon: (ftsteutates) Rely on subsystem locking
      hwmon: (ina238) Rely on subsystem locking
      hwmon: (lm95241) Rely on subsystem locking
      hwmon: (aht10) Rely on subsystem locking
      hwmon: (adt7411) Rely on subsystem locking
      hwmon: (ltc2947-core) Rely on subsystem locking
      hwmon: (peci) Rely on subsystem locking
      hwmon: (adt7x10) Rely on subsystem locking
      hwmon: (sfctemp) Rely on subsystem locking
      hwmon: (lochnagar-hwmon) Rely on subsystem locking
      hwmon: (ltc4282) Rely on subsystem locking
      hwmon: (aquacomputer_d5next) Rely on subsystem locking
      hwmon: (gpd-fan) Rely on subsystem locking
      hwmon: (i5500_temp) Drop unnecessary include files
      hwmon: (asus_rog_ryujin) Rely on subsystem locking
      hwmon: (chipcap2) Drop unnecessary include files
      hwmon: (corsair-psu) Rely on subsystem locking
      hwmon: (corsair-psu) Rely on subsystem locking

 drivers/hwmon/adt7411.c             | 59 +++++++-------------------
 drivers/hwmon/adt7x10.c             | 27 +++---------
 drivers/hwmon/aht10.c               | 24 ++---------
 drivers/hwmon/aquacomputer_d5next.c | 37 +++-------------
 drivers/hwmon/asus_rog_ryujin.c     | 48 ++++-----------------
 drivers/hwmon/chipcap2.c            |  7 ----
 drivers/hwmon/corsair-psu.c         | 13 +-----
 drivers/hwmon/ftsteutates.c         | 84 +++++++++++--------------------------
 drivers/hwmon/gpd-fan.c             | 56 ++++++-------------------
 drivers/hwmon/hs3001.c              | 10 +----
 drivers/hwmon/i5500_temp.c          |  3 --
 drivers/hwmon/ina238.c              | 26 +++---------
 drivers/hwmon/ina2xx.c              | 28 +++++--------
 drivers/hwmon/ina3221.c             | 19 ---------
 drivers/hwmon/k10temp.c             |  5 ---
 drivers/hwmon/lm92.c                | 11 +----
 drivers/hwmon/lm95234.c             | 12 +-----
 drivers/hwmon/lm95241.c             | 16 -------
 drivers/hwmon/lochnagar-hwmon.c     | 18 ++------
 drivers/hwmon/ltc2947-core.c        | 32 +++-----------
 drivers/hwmon/ltc4282.c             | 32 ++------------
 drivers/hwmon/max127.c              | 23 ++--------
 drivers/hwmon/mr75203.c             |  1 -
 drivers/hwmon/npcm750-pwm-fan.c     | 11 +----
 drivers/hwmon/peci/common.h         |  3 --
 drivers/hwmon/peci/cputemp.c        | 72 +++++++++----------------------
 drivers/hwmon/peci/dimmtemp.c       | 17 ++------
 drivers/hwmon/powr1220.c            | 17 ++------
 drivers/hwmon/sbtsi_temp.c          | 17 +-------
 drivers/hwmon/sfctemp.c             | 36 ++++------------
 drivers/hwmon/sht4x.c               | 40 +++++-------------
 31 files changed, 163 insertions(+), 641 deletions(-)

[PATCH 01/29] hwmon: (max127) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/max127.c | 23 +++--------------------
 1 file changed, 3 insertions(+), 20 deletions(-)

diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c
index a9aab8862f5e..5102d86d2619 100644
--- a/drivers/hwmon/max127.c
+++ b/drivers/hwmon/max127.c
@@ -45,7 +45,6 @@
 #define MAX127_SIGN_BIT		BIT(11)
 
 struct max127_data {
-	struct mutex lock;
 	struct i2c_client *client;
 	u8 ctrl_byte[MAX127_NUM_CHANNELS];
 };
@@ -121,21 +120,16 @@ static int max127_read_input(struct max127_data *data, int channel, long *val)
 	struct i2c_client *client = data->client;
 	u8 ctrl_byte = data->ctrl_byte[channel];
 
-	mutex_lock(&data->lock);
-
 	status = max127_select_channel(client, ctrl_byte);
 	if (status)
-		goto exit;
+		return status;
 
 	status = max127_read_channel(client, &raw);
 	if (status)
-		goto exit;
+		return status;
 
 	*val = max127_process_raw(ctrl_byte, raw);
-
-exit:
-	mutex_unlock(&data->lock);
-	return status;
+	return 0;
 }
 
 static int max127_read_min(struct max127_data *data, int channel, long *val)
@@ -170,8 +164,6 @@ static int max127_write_min(struct max127_data *data, int channel, long val)
 {
 	u8 ctrl;
 
-	mutex_lock(&data->lock);
-
 	ctrl = data->ctrl_byte[channel];
 	if (val <= -MAX127_FULL_RANGE) {
 		ctrl |= (MAX127_CTRL_RNG | MAX127_CTRL_BIP);
@@ -182,23 +174,15 @@ static int max127_write_min(struct max127_data *data, int channel, long val)
 		ctrl &= ~MAX127_CTRL_BIP;
 	}
 	data->ctrl_byte[channel] = ctrl;
-
-	mutex_unlock(&data->lock);
-
 	return 0;
 }
 
 static int max127_write_max(struct max127_data *data, int channel, long val)
 {
-	mutex_lock(&data->lock);
-
 	if (val >= MAX127_FULL_RANGE)
 		data->ctrl_byte[channel] |= MAX127_CTRL_RNG;
 	else
 		data->ctrl_byte[channel] &= ~MAX127_CTRL_RNG;
-
-	mutex_unlock(&data->lock);
-
 	return 0;
 }
 
@@ -315,7 +299,6 @@ static int max127_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	data->client = client;
-	mutex_init(&data->lock);
 	for (i = 0; i < ARRAY_SIZE(data->ctrl_byte); i++)
 		data->ctrl_byte[i] = (MAX127_CTRL_START |
 				      MAX127_SET_CHANNEL(i));
-- 
2.45.2

[PATCH 02/29] hwmon: (lm95234) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm95234.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/hwmon/lm95234.c b/drivers/hwmon/lm95234.c
index 7da6c8f07332..387b3ba81dbf 100644
--- a/drivers/hwmon/lm95234.c
+++ b/drivers/hwmon/lm95234.c
@@ -14,7 +14,6 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/slab.h>
-#include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/util_macros.h>
 
@@ -54,7 +53,6 @@ static const unsigned short normal_i2c[] = {
 /* Client data (each client gets its own) */
 struct lm95234_data {
 	struct regmap *regmap;
-	struct mutex update_lock;
 	enum chips type;
 };
 
@@ -107,19 +105,14 @@ static ssize_t lm95234_hyst_set(struct lm95234_data *data, long val)
 	u32 tcrit;
 	int ret;
 
-	mutex_lock(&data->update_lock);
-
 	ret = regmap_read(data->regmap, LM95234_REG_TCRIT1(0), &tcrit);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	val = DIV_ROUND_CLOSEST(clamp_val(val, -255000, 255000), 1000);
 	val = clamp_val((int)tcrit - val, 0, 31);
 
-	ret = regmap_write(data->regmap, LM95234_REG_TCRIT_HYST, val);
-unlock:
-	mutex_unlock(&data->update_lock);
-	return ret;
+	return regmap_write(data->regmap, LM95234_REG_TCRIT_HYST, val);
 }
 
 static int lm95234_crit_reg(int channel)
@@ -526,7 +519,6 @@ static int lm95234_probe(struct i2c_client *client)
 		return PTR_ERR(regmap);
 
 	data->regmap = regmap;
-	mutex_init(&data->update_lock);
 
 	/* Initialize the LM95234 chip */
 	err = lm95234_init_client(dev, regmap);
-- 
2.45.2

[PATCH 03/29] hwmon: (lm92) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm92.c | 11 ++---------
 1 file changed, 2 insertions(+), 9 deletions(-)

diff --git a/drivers/hwmon/lm92.c b/drivers/hwmon/lm92.c
index 0be439b38ee1..91a6b7525bb6 100644
--- a/drivers/hwmon/lm92.c
+++ b/drivers/hwmon/lm92.c
@@ -32,7 +32,6 @@
 #include <linux/i2c.h>
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
 
@@ -78,7 +77,6 @@ static inline u8 ALARMS_FROM_REG(s16 reg)
 /* Client data (each client gets its own) */
 struct lm92_data {
 	struct regmap *regmap;
-	struct mutex update_lock;
 	int resolution;
 };
 
@@ -199,15 +197,11 @@ static int lm92_temp_write(struct lm92_data *data, u32 attr, long val)
 		break;
 	case hwmon_temp_crit_hyst:
 		val = clamp_val(val, -120000, 220000);
-		mutex_lock(&data->update_lock);
 		err = regmap_read(regmap, LM92_REG_TEMP_CRIT, &temp);
 		if (err)
-			goto unlock;
+			return err;
 		val = TEMP_TO_REG(TEMP_FROM_REG(temp) - val, data->resolution);
-		err = regmap_write(regmap, LM92_REG_TEMP_HYST, val);
-unlock:
-		mutex_unlock(&data->update_lock);
-		return err;
+		return regmap_write(regmap, LM92_REG_TEMP_HYST, val);
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -396,7 +390,6 @@ static int lm92_probe(struct i2c_client *client)
 
 	data->regmap = regmap;
 	data->resolution = (unsigned long)i2c_get_match_data(client);
-	mutex_init(&data->update_lock);
 
 	/* Initialize the chipset */
 	err = lm92_init_client(regmap);
-- 
2.45.2

[PATCH 04/29] hwmon: (hs3001) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/hs3001.c | 10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/drivers/hwmon/hs3001.c b/drivers/hwmon/hs3001.c
index 24ed3fb9a43a..50c6c15f8b18 100644
--- a/drivers/hwmon/hs3001.c
+++ b/drivers/hwmon/hs3001.c
@@ -42,7 +42,6 @@
 
 struct hs3001_data {
 	struct i2c_client *client;
-	struct mutex i2c_lock; /* lock for sending i2c commands */
 	u32 wait_time;		/* in us */
 	int temperature;	/* in milli degree */
 	u32 humidity;		/* in milli % */
@@ -112,12 +111,9 @@ static int hs3001_read(struct device *dev, enum hwmon_sensor_types type,
 	struct i2c_client *client = data->client;
 	int ret;
 
-	mutex_lock(&data->i2c_lock);
 	ret = i2c_master_send(client, NULL, 0);
-	if (ret < 0) {
-		mutex_unlock(&data->i2c_lock);
+	if (ret < 0)
 		return ret;
-	}
 
 	/*
 	 * Sensor needs some time to process measurement depending on
@@ -126,8 +122,6 @@ static int hs3001_read(struct device *dev, enum hwmon_sensor_types type,
 	fsleep(data->wait_time);
 
 	ret = hs3001_data_fetch_command(client, data);
-	mutex_unlock(&data->i2c_lock);
-
 	if (ret < 0)
 		return ret;
 
@@ -211,8 +205,6 @@ static int hs3001_probe(struct i2c_client *client)
 	data->wait_time = (HS3001_WAKEUP_TIME + HS3001_14BIT_RESOLUTION +
 			   HS3001_14BIT_RESOLUTION);
 
-	mutex_init(&data->i2c_lock);
-
 	hwmon_dev = devm_hwmon_device_register_with_info(dev,
 							 client->name,
 							 data,
-- 
2.45.2

[PATCH 05/29] hwmon: (sbtsi_temp) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/sbtsi_temp.c | 17 ++---------------
 1 file changed, 2 insertions(+), 15 deletions(-)

diff --git a/drivers/hwmon/sbtsi_temp.c b/drivers/hwmon/sbtsi_temp.c
index a6c439e376ff..c5b2488c4c7f 100644
--- a/drivers/hwmon/sbtsi_temp.c
+++ b/drivers/hwmon/sbtsi_temp.c
@@ -12,7 +12,6 @@
 #include <linux/init.h>
 #include <linux/hwmon.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/bitfield.h>
 
@@ -52,7 +51,6 @@
 /* Each client has this additional data */
 struct sbtsi_data {
 	struct i2c_client *client;
-	struct mutex lock;
 	bool ext_range_mode;
 	bool read_order;
 };
@@ -94,7 +92,6 @@ static int sbtsi_read(struct device *dev, enum hwmon_sensor_types type,
 
 	switch (attr) {
 	case hwmon_temp_input:
-		mutex_lock(&data->lock);
 		if (data->read_order) {
 			temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_DEC);
 			temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_INT);
@@ -102,19 +99,14 @@ static int sbtsi_read(struct device *dev, enum hwmon_sensor_types type,
 			temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_INT);
 			temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_DEC);
 		}
-		mutex_unlock(&data->lock);
 		break;
 	case hwmon_temp_max:
-		mutex_lock(&data->lock);
 		temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_HIGH_INT);
 		temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_HIGH_DEC);
-		mutex_unlock(&data->lock);
 		break;
 	case hwmon_temp_min:
-		mutex_lock(&data->lock);
 		temp_int = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_LOW_INT);
 		temp_dec = i2c_smbus_read_byte_data(data->client, SBTSI_REG_TEMP_LOW_DEC);
-		mutex_unlock(&data->lock);
 		break;
 	default:
 		return -EINVAL;
@@ -158,15 +150,11 @@ static int sbtsi_write(struct device *dev, enum hwmon_sensor_types type,
 	val = clamp_val(val, SBTSI_TEMP_MIN, SBTSI_TEMP_MAX);
 	sbtsi_mc_to_reg(val, &temp_int, &temp_dec);
 
-	mutex_lock(&data->lock);
 	err = i2c_smbus_write_byte_data(data->client, reg_int, temp_int);
 	if (err)
-		goto exit;
+		return err;
 
-	err = i2c_smbus_write_byte_data(data->client, reg_dec, temp_dec);
-exit:
-	mutex_unlock(&data->lock);
-	return err;
+	return i2c_smbus_write_byte_data(data->client, reg_dec, temp_dec);
 }
 
 static umode_t sbtsi_is_visible(const void *data,
@@ -219,7 +207,6 @@ static int sbtsi_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	data->client = client;
-	mutex_init(&data->lock);
 
 	err = i2c_smbus_read_byte_data(data->client, SBTSI_REG_CONFIG);
 	if (err < 0)
-- 
2.45.2

[PATCH 06/29] hwmon: (ina2xx) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina2xx.c | 28 ++++++++++------------------
 1 file changed, 10 insertions(+), 18 deletions(-)

diff --git a/drivers/hwmon/ina2xx.c b/drivers/hwmon/ina2xx.c
index bc3c1f7314b3..69ac0468dee4 100644
--- a/drivers/hwmon/ina2xx.c
+++ b/drivers/hwmon/ina2xx.c
@@ -156,7 +156,6 @@ struct ina2xx_data {
 	long rshunt;
 	long current_lsb_uA;
 	long power_lsb_uW;
-	struct mutex config_lock;
 	struct regmap *regmap;
 	struct i2c_client *client;
 };
@@ -390,22 +389,19 @@ static int ina226_alert_limit_read(struct ina2xx_data *data, u32 mask, int reg,
 	int regval;
 	int ret;
 
-	mutex_lock(&data->config_lock);
 	ret = regmap_read(regmap, INA226_MASK_ENABLE, &regval);
 	if (ret)
-		goto abort;
+		return ret;
 
 	if (regval & mask) {
 		ret = regmap_read(regmap, INA226_ALERT_LIMIT, &regval);
 		if (ret)
-			goto abort;
+			return ret;
 		*val = ina2xx_get_value(data, reg, regval);
 	} else {
 		*val = 0;
 	}
-abort:
-	mutex_unlock(&data->config_lock);
-	return ret;
+	return 0;
 }
 
 static int ina226_alert_limit_write(struct ina2xx_data *data, u32 mask, int reg, long val)
@@ -421,23 +417,20 @@ static int ina226_alert_limit_write(struct ina2xx_data *data, u32 mask, int reg,
 	 * due to register write sequence. Then, only enable the alert
 	 * if the value is non-zero.
 	 */
-	mutex_lock(&data->config_lock);
 	ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
 				 INA226_ALERT_CONFIG_MASK, 0);
 	if (ret < 0)
-		goto abort;
+		return ret;
 
 	ret = regmap_write(regmap, INA226_ALERT_LIMIT,
 			   ina226_alert_to_reg(data, reg, val));
 	if (ret < 0)
-		goto abort;
+		return ret;
 
 	if (val)
-		ret = regmap_update_bits(regmap, INA226_MASK_ENABLE,
-					 INA226_ALERT_CONFIG_MASK, mask);
-abort:
-	mutex_unlock(&data->config_lock);
-	return ret;
+		return regmap_update_bits(regmap, INA226_MASK_ENABLE,
+					  INA226_ALERT_CONFIG_MASK, mask);
+	return 0;
 }
 
 static int ina2xx_chip_read(struct device *dev, u32 attr, long *val)
@@ -859,9 +852,9 @@ static ssize_t shunt_resistor_store(struct device *dev,
 	if (status < 0)
 		return status;
 
-	mutex_lock(&data->config_lock);
+	hwmon_lock(dev);
 	status = ina2xx_set_shunt(data, val);
-	mutex_unlock(&data->config_lock);
+	hwmon_unlock(dev);
 	if (status < 0)
 		return status;
 	return count;
@@ -951,7 +944,6 @@ static int ina2xx_probe(struct i2c_client *client)
 	data->client = client;
 	data->config = &ina2xx_config[chip];
 	data->chip = chip;
-	mutex_init(&data->config_lock);
 
 	data->regmap = devm_regmap_init_i2c(client, &ina2xx_regmap_config);
 	if (IS_ERR(data->regmap)) {
-- 
2.45.2

[PATCH 07/29] hwmon: (sht4x) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/sht4x.c | 40 +++++++++++-----------------------------
 1 file changed, 11 insertions(+), 29 deletions(-)

diff --git a/drivers/hwmon/sht4x.c b/drivers/hwmon/sht4x.c
index 6c9b776237c2..5abe1227e109 100644
--- a/drivers/hwmon/sht4x.c
+++ b/drivers/hwmon/sht4x.c
@@ -55,7 +55,6 @@ DECLARE_CRC8_TABLE(sht4x_crc8_table);
 /**
  * struct sht4x_data - All the data required to operate an SHT4X chip
  * @client: the i2c client associated with the SHT4X
- * @lock: a mutex that is used to prevent parallel access to the i2c client
  * @heating_complete: the time that the last heating finished
  * @data_pending: true if and only if there are measurements to retrieve after heating
  * @heater_power: the power at which the heater will be started
@@ -68,7 +67,6 @@ DECLARE_CRC8_TABLE(sht4x_crc8_table);
  */
 struct sht4x_data {
 	struct i2c_client	*client;
-	struct mutex		lock;	/* atomic read data updates */
 	unsigned long		heating_complete;	/* in jiffies */
 	bool			data_pending;
 	u32			heater_power;	/* in milli-watts */
@@ -87,7 +85,7 @@ struct sht4x_data {
  */
 static int sht4x_read_values(struct sht4x_data *data)
 {
-	int ret = 0;
+	int ret;
 	u16 t_ticks, rh_ticks;
 	unsigned long next_update;
 	struct i2c_client *client = data->client;
@@ -96,8 +94,6 @@ static int sht4x_read_values(struct sht4x_data *data)
 	u8 raw_data[SHT4X_RESPONSE_LENGTH];
 	unsigned long curr_jiffies;
 
-	mutex_lock(&data->lock);
-
 	curr_jiffies = jiffies;
 	if (time_before(curr_jiffies, data->heating_complete))
 		msleep(jiffies_to_msecs(data->heating_complete - curr_jiffies));
@@ -110,11 +106,11 @@ static int sht4x_read_values(struct sht4x_data *data)
 			msecs_to_jiffies(data->update_interval);
 
 		if (data->valid && time_before_eq(jiffies, next_update))
-			goto unlock;
+			return 0;
 
 		ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN);
 		if (ret < 0)
-			goto unlock;
+			return ret;
 
 		usleep_range(SHT4X_MEAS_DELAY_HPM, SHT4X_MEAS_DELAY_HPM + SHT4X_DELAY_EXTRA);
 	}
@@ -123,7 +119,7 @@ static int sht4x_read_values(struct sht4x_data *data)
 	if (ret != SHT4X_RESPONSE_LENGTH) {
 		if (ret >= 0)
 			ret = -ENODATA;
-		goto unlock;
+		return ret;
 	}
 
 	t_ticks = raw_data[0] << 8 | raw_data[1];
@@ -132,26 +128,20 @@ static int sht4x_read_values(struct sht4x_data *data)
 	crc = crc8(sht4x_crc8_table, &raw_data[0], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
 	if (crc != raw_data[2]) {
 		dev_err(&client->dev, "data integrity check failed\n");
-		ret = -EIO;
-		goto unlock;
+		return -EIO;
 	}
 
 	crc = crc8(sht4x_crc8_table, &raw_data[3], SHT4X_WORD_LEN, CRC8_INIT_VALUE);
 	if (crc != raw_data[5]) {
 		dev_err(&client->dev, "data integrity check failed\n");
-		ret = -EIO;
-		goto unlock;
+		return -EIO;
 	}
 
 	data->temperature = ((21875 * (int32_t)t_ticks) >> 13) - 45000;
 	data->humidity = ((15625 * (int32_t)rh_ticks) >> 13) - 6000;
 	data->last_updated = jiffies;
 	data->valid = true;
-	ret = 0;
-
-unlock:
-	mutex_unlock(&data->lock);
-	return ret;
+	return 0;
 }
 
 static ssize_t sht4x_interval_write(struct sht4x_data *data, long val)
@@ -287,22 +277,16 @@ static ssize_t heater_enable_store(struct device *dev,
 		heating_time_bound = 1100;
 	}
 
-	mutex_lock(&data->lock);
-
-	if (time_before(jiffies, data->heating_complete)) {
-		ret = -EBUSY;
-		goto unlock;
-	}
+	if (time_before(jiffies, data->heating_complete))
+		return -EBUSY;
 
 	ret = i2c_master_send(data->client, &cmd, SHT4X_CMD_LEN);
 	if (ret < 0)
-		goto unlock;
+		return ret;
 
 	data->heating_complete = jiffies + msecs_to_jiffies(heating_time_bound);
 	data->data_pending = true;
-unlock:
-	mutex_unlock(&data->lock);
-	return ret;
+	return 0;
 }
 
 static ssize_t heater_power_show(struct device *dev,
@@ -422,8 +406,6 @@ static int sht4x_probe(struct i2c_client *client)
 	data->heater_time = 1000;
 	data->heating_complete = jiffies;
 
-	mutex_init(&data->lock);
-
 	crc8_populate_msb(sht4x_crc8_table, SHT4X_CRC8_POLYNOMIAL);
 
 	ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN);
-- 
2.45.2

[PATCH 08/29] hwmon: (ina3221) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina3221.c | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/drivers/hwmon/ina3221.c b/drivers/hwmon/ina3221.c
index ce0e3f214f5b..5ecc68dcf169 100644
--- a/drivers/hwmon/ina3221.c
+++ b/drivers/hwmon/ina3221.c
@@ -11,7 +11,6 @@
 #include <linux/hwmon-sysfs.h>
 #include <linux/i2c.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/pm_runtime.h>
 #include <linux/regmap.h>
@@ -115,7 +114,6 @@ struct ina3221_input {
  * @regmap: Register map of the device
  * @fields: Register fields of the device
  * @inputs: Array of channel input source specific structures
- * @lock: mutex lock to serialize sysfs attribute accesses
  * @reg_config: Register value of INA3221_CONFIG
  * @summation_shunt_resistor: equivalent shunt resistor value for summation
  * @summation_channel_control: Value written to SCC field in INA3221_MASK_ENABLE
@@ -126,7 +124,6 @@ struct ina3221_data {
 	struct regmap *regmap;
 	struct regmap_field *fields[F_MAX_FIELDS];
 	struct ina3221_input inputs[INA3221_NUM_CHANNELS];
-	struct mutex lock;
 	u32 reg_config;
 	int summation_shunt_resistor;
 	u32 summation_channel_control;
@@ -530,11 +527,8 @@ static int ina3221_write_enable(struct device *dev, int channel, bool enable)
 static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long *val)
 {
-	struct ina3221_data *ina = dev_get_drvdata(dev);
 	int ret;
 
-	mutex_lock(&ina->lock);
-
 	switch (type) {
 	case hwmon_chip:
 		ret = ina3221_read_chip(dev, attr, val);
@@ -550,20 +544,14 @@ static int ina3221_read(struct device *dev, enum hwmon_sensor_types type,
 		ret = -EOPNOTSUPP;
 		break;
 	}
-
-	mutex_unlock(&ina->lock);
-
 	return ret;
 }
 
 static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
 			 u32 attr, int channel, long val)
 {
-	struct ina3221_data *ina = dev_get_drvdata(dev);
 	int ret;
 
-	mutex_lock(&ina->lock);
-
 	switch (type) {
 	case hwmon_chip:
 		ret = ina3221_write_chip(dev, attr, val);
@@ -579,9 +567,6 @@ static int ina3221_write(struct device *dev, enum hwmon_sensor_types type,
 		ret = -EOPNOTSUPP;
 		break;
 	}
-
-	mutex_unlock(&ina->lock);
-
 	return ret;
 }
 
@@ -886,7 +871,6 @@ static int ina3221_probe(struct i2c_client *client)
 	}
 
 	ina->pm_dev = dev;
-	mutex_init(&ina->lock);
 	dev_set_drvdata(dev, ina);
 
 	/* Enable PM runtime -- status is suspended by default */
@@ -925,7 +909,6 @@ static int ina3221_probe(struct i2c_client *client)
 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
 		pm_runtime_put_noidle(ina->pm_dev);
-	mutex_destroy(&ina->lock);
 
 	return ret;
 }
@@ -941,8 +924,6 @@ static void ina3221_remove(struct i2c_client *client)
 	/* pm_runtime_put_noidle() will decrease the PM refcount until 0 */
 	for (i = 0; i < INA3221_NUM_CHANNELS; i++)
 		pm_runtime_put_noidle(ina->pm_dev);
-
-	mutex_destroy(&ina->lock);
 }
 
 static int ina3221_suspend(struct device *dev)
-- 
2.45.2

[PATCH 09/29] hwmon: (k10temp) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/k10temp.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/drivers/hwmon/k10temp.c b/drivers/hwmon/k10temp.c
index b98d5ec72c4f..7fc1d97a9971 100644
--- a/drivers/hwmon/k10temp.c
+++ b/drivers/hwmon/k10temp.c
@@ -31,9 +31,6 @@ static bool force;
 module_param(force, bool, 0444);
 MODULE_PARM_DESC(force, "force loading on processors with erratum 319");
 
-/* Provide lock for writing to NB_SMU_IND_ADDR */
-static DEFINE_MUTEX(nb_smu_ind_mutex);
-
 #ifndef PCI_DEVICE_ID_AMD_15H_M70H_NB_F3
 #define PCI_DEVICE_ID_AMD_15H_M70H_NB_F3	0x15b3
 #endif
@@ -137,12 +134,10 @@ static void read_tempreg_pci(struct pci_dev *pdev, u32 *regval)
 static void amd_nb_index_read(struct pci_dev *pdev, unsigned int devfn,
 			      unsigned int base, int offset, u32 *val)
 {
-	mutex_lock(&nb_smu_ind_mutex);
 	pci_bus_write_config_dword(pdev->bus, devfn,
 				   base, offset);
 	pci_bus_read_config_dword(pdev->bus, devfn,
 				  base + 4, val);
-	mutex_unlock(&nb_smu_ind_mutex);
 }
 
 static void read_htcreg_nb_f15(struct pci_dev *pdev, u32 *regval)
-- 
2.45.2

[PATCH 10/29] hwmon: (mr75203) Drop unnecessary include file

[Guenter Roeck]

The driver does not perform any locking and thus does not need to
include mutex.h. Drop the unnecessary include file.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/mr75203.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
index 7848198f8996..32c1e42e1278 100644
--- a/drivers/hwmon/mr75203.c
+++ b/drivers/hwmon/mr75203.c
@@ -14,7 +14,6 @@
 #include <linux/kstrtox.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
-#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
 #include <linux/regmap.h>
-- 
2.45.2

[PATCH 11/29] hwmon: (powr1220) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/powr1220.c | 17 ++++-------------
 1 file changed, 4 insertions(+), 13 deletions(-)

diff --git a/drivers/hwmon/powr1220.c b/drivers/hwmon/powr1220.c
index 5f9ca6543530..06a2c56016d1 100644
--- a/drivers/hwmon/powr1220.c
+++ b/drivers/hwmon/powr1220.c
@@ -16,7 +16,6 @@
 #include <linux/hwmon.h>
 #include <linux/hwmon-sysfs.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 #include <linux/delay.h>
 
 #define ADC_STEP_MV			2
@@ -75,7 +74,6 @@ enum powr1220_adc_values {
 
 struct powr1220_data {
 	struct i2c_client *client;
-	struct mutex update_lock;
 	u8 max_channels;
 	bool adc_valid[MAX_POWR1220_ADC_VALUES];
 	 /* the next value is in jiffies */
@@ -111,8 +109,6 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 	int result;
 	int adc_range = 0;
 
-	mutex_lock(&data->update_lock);
-
 	if (time_after(jiffies, data->adc_last_updated[ch_num] + HZ) ||
 	    !data->adc_valid[ch_num]) {
 		/*
@@ -128,8 +124,8 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 		/* set the attenuator and mux */
 		result = i2c_smbus_write_byte_data(data->client, ADC_MUX,
 						   adc_range | ch_num);
-		if (result)
-			goto exit;
+		if (result < 0)
+			return result;
 
 		/*
 		 * wait at least Tconvert time (200 us) for the
@@ -140,14 +136,14 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 		/* get the ADC reading */
 		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_LOW);
 		if (result < 0)
-			goto exit;
+			return result;
 
 		reading = result >> 4;
 
 		/* get the upper half of the reading */
 		result = i2c_smbus_read_byte_data(data->client, ADC_VALUE_HIGH);
 		if (result < 0)
-			goto exit;
+			return result;
 
 		reading |= result << 4;
 
@@ -163,10 +159,6 @@ static int powr1220_read_adc(struct device *dev, int ch_num)
 	} else {
 		result = data->adc_values[ch_num];
 	}
-
-exit:
-	mutex_unlock(&data->update_lock);
-
 	return result;
 }
 
@@ -302,7 +294,6 @@ static int powr1220_probe(struct i2c_client *client)
 		break;
 	}
 
-	mutex_init(&data->update_lock);
 	data->client = client;
 
 	hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
-- 
2.45.2

[PATCH 12/29] hwmon: (ftsteutates) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ftsteutates.c | 84 +++++++++++--------------------------
 1 file changed, 25 insertions(+), 59 deletions(-)

diff --git a/drivers/hwmon/ftsteutates.c b/drivers/hwmon/ftsteutates.c
index 8aeec16a7a90..08dcc6a7fb62 100644
--- a/drivers/hwmon/ftsteutates.c
+++ b/drivers/hwmon/ftsteutates.c
@@ -12,7 +12,6 @@
 #include <linux/jiffies.h>
 #include <linux/math.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/watchdog.h>
 
@@ -62,10 +61,6 @@ enum WATCHDOG_RESOLUTION {
 
 struct fts_data {
 	struct i2c_client *client;
-	/* update sensor data lock */
-	struct mutex update_lock;
-	/* read/write register lock */
-	struct mutex access_lock;
 	unsigned long last_updated; /* in jiffies */
 	struct watchdog_device wdd;
 	enum WATCHDOG_RESOLUTION resolution;
@@ -98,21 +93,15 @@ static int fts_read_byte(struct i2c_client *client, unsigned short reg)
 {
 	int ret;
 	unsigned char page = reg >> 8;
-	struct fts_data *data = dev_get_drvdata(&client->dev);
-
-	mutex_lock(&data->access_lock);
 
 	dev_dbg(&client->dev, "page select - page: 0x%.02x\n", page);
 	ret = i2c_smbus_write_byte_data(client, FTS_PAGE_SELECT_REG, page);
 	if (ret < 0)
-		goto error;
+		return ret;
 
 	reg &= 0xFF;
 	ret = i2c_smbus_read_byte_data(client, reg);
 	dev_dbg(&client->dev, "read - reg: 0x%.02x: val: 0x%.02x\n", reg, ret);
-
-error:
-	mutex_unlock(&data->access_lock);
 	return ret;
 }
 
@@ -121,22 +110,16 @@ static int fts_write_byte(struct i2c_client *client, unsigned short reg,
 {
 	int ret;
 	unsigned char page = reg >> 8;
-	struct fts_data *data = dev_get_drvdata(&client->dev);
-
-	mutex_lock(&data->access_lock);
 
 	dev_dbg(&client->dev, "page select - page: 0x%.02x\n", page);
 	ret = i2c_smbus_write_byte_data(client, FTS_PAGE_SELECT_REG, page);
 	if (ret < 0)
-		goto error;
+		return ret;
 
 	reg &= 0xFF;
 	dev_dbg(&client->dev,
 		"write - reg: 0x%.02x: val: 0x%.02x\n", reg, value);
 	ret = i2c_smbus_write_byte_data(client, reg, value);
-
-error:
-	mutex_unlock(&data->access_lock);
 	return ret;
 }
 
@@ -145,44 +128,40 @@ static int fts_write_byte(struct i2c_client *client, unsigned short reg,
 /*****************************************************************************/
 static int fts_update_device(struct fts_data *data)
 {
-	int i;
-	int err = 0;
+	int i, err;
 
-	mutex_lock(&data->update_lock);
 	if (!time_after(jiffies, data->last_updated + 2 * HZ) && data->valid)
-		goto exit;
+		return 0;
 
 	err = fts_read_byte(data->client, FTS_DEVICE_STATUS_REG);
 	if (err < 0)
-		goto exit;
+		return err;
 
 	data->valid = !!(err & 0x02); /* Data not ready yet */
-	if (unlikely(!data->valid)) {
-		err = -EAGAIN;
-		goto exit;
-	}
+	if (unlikely(!data->valid))
+		return -EAGAIN;
 
 	err = fts_read_byte(data->client, FTS_FAN_PRESENT_REG);
 	if (err < 0)
-		goto exit;
+		return err;
 	data->fan_present = err;
 
 	err = fts_read_byte(data->client, FTS_FAN_EVENT_REG);
 	if (err < 0)
-		goto exit;
+		return err;
 	data->fan_alarm = err;
 
 	for (i = 0; i < FTS_NO_FAN_SENSORS; i++) {
 		if (data->fan_present & BIT(i)) {
 			err = fts_read_byte(data->client, FTS_REG_FAN_INPUT(i));
 			if (err < 0)
-				goto exit;
+				return err;
 			data->fan_input[i] = err;
 
 			err = fts_read_byte(data->client,
 					    FTS_REG_FAN_SOURCE(i));
 			if (err < 0)
-				goto exit;
+				return err;
 			data->fan_source[i] = err;
 		} else {
 			data->fan_input[i] = 0;
@@ -192,27 +171,24 @@ static int fts_update_device(struct fts_data *data)
 
 	err = fts_read_byte(data->client, FTS_SENSOR_EVENT_REG);
 	if (err < 0)
-		goto exit;
+		return err;
 	data->temp_alarm = err;
 
 	for (i = 0; i < FTS_NO_TEMP_SENSORS; i++) {
 		err = fts_read_byte(data->client, FTS_REG_TEMP_INPUT(i));
 		if (err < 0)
-			goto exit;
+			return err;
 		data->temp_input[i] = err;
 	}
 
 	for (i = 0; i < FTS_NO_VOLT_SENSORS; i++) {
 		err = fts_read_byte(data->client, FTS_REG_VOLT(i));
 		if (err < 0)
-			goto exit;
+			return err;
 		data->volt[i] = err;
 	}
 	data->last_updated = jiffies;
-	err = 0;
-exit:
-	mutex_unlock(&data->update_lock);
-	return err;
+	return 0;
 }
 
 /*****************************************************************************/
@@ -470,18 +446,14 @@ static int fts_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 			if (val)
 				return -EINVAL;
 
-			mutex_lock(&data->update_lock);
 			ret = fts_read_byte(data->client, FTS_REG_TEMP_CONTROL(channel));
-			if (ret >= 0)
-				ret = fts_write_byte(data->client, FTS_REG_TEMP_CONTROL(channel),
-						     ret | 0x1);
-			if (ret >= 0)
-				data->valid = false;
-
-			mutex_unlock(&data->update_lock);
 			if (ret < 0)
 				return ret;
-
+			ret = fts_write_byte(data->client, FTS_REG_TEMP_CONTROL(channel),
+					     ret | 0x1);
+			if (ret < 0)
+				return ret;
+			data->valid = false;
 			return 0;
 		default:
 			break;
@@ -493,18 +465,14 @@ static int fts_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 			if (val)
 				return -EINVAL;
 
-			mutex_lock(&data->update_lock);
 			ret = fts_read_byte(data->client, FTS_REG_FAN_CONTROL(channel));
-			if (ret >= 0)
-				ret = fts_write_byte(data->client, FTS_REG_FAN_CONTROL(channel),
-						     ret | 0x1);
-			if (ret >= 0)
-				data->valid = false;
-
-			mutex_unlock(&data->update_lock);
 			if (ret < 0)
 				return ret;
-
+			ret = fts_write_byte(data->client, FTS_REG_FAN_CONTROL(channel),
+					     ret | 0x1);
+			if (ret < 0)
+				return ret;
+			data->valid = false;
 			return 0;
 		default:
 			break;
@@ -648,8 +616,6 @@ static int fts_probe(struct i2c_client *client)
 	if (!data)
 		return -ENOMEM;
 
-	mutex_init(&data->update_lock);
-	mutex_init(&data->access_lock);
 	data->client = client;
 	dev_set_drvdata(&client->dev, data);
 
-- 
2.45.2

[PATCH 13/29] hwmon: (ina238) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ina238.c | 26 +++++---------------------
 1 file changed, 5 insertions(+), 21 deletions(-)

diff --git a/drivers/hwmon/ina238.c b/drivers/hwmon/ina238.c
index 356d19b7675c..ff67b03189f7 100644
--- a/drivers/hwmon/ina238.c
+++ b/drivers/hwmon/ina238.c
@@ -117,7 +117,6 @@ struct ina238_config {
 struct ina238_data {
 	const struct ina238_config *config;
 	struct i2c_client *client;
-	struct mutex config_lock;
 	struct regmap *regmap;
 	u32 rshunt;
 	int gain;
@@ -607,31 +606,18 @@ static int ina238_read(struct device *dev, enum hwmon_sensor_types type,
 static int ina238_write(struct device *dev, enum hwmon_sensor_types type,
 			u32 attr, int channel, long val)
 {
-	struct ina238_data *data = dev_get_drvdata(dev);
-	int err;
-
-	mutex_lock(&data->config_lock);
-
 	switch (type) {
 	case hwmon_in:
-		err = ina238_write_in(dev, attr, channel, val);
-		break;
+		return ina238_write_in(dev, attr, channel, val);
 	case hwmon_curr:
-		err = ina238_write_curr(dev, attr, val);
-		break;
+		return ina238_write_curr(dev, attr, val);
 	case hwmon_power:
-		err = ina238_write_power_max(dev, val);
-		break;
+		return ina238_write_power_max(dev, val);
 	case hwmon_temp:
-		err = ina238_write_temp_max(dev, val);
-		break;
+		return ina238_write_temp_max(dev, val);
 	default:
-		err = -EOPNOTSUPP;
-		break;
+		return -EOPNOTSUPP;
 	}
-
-	mutex_unlock(&data->config_lock);
-	return err;
 }
 
 static umode_t ina238_is_visible(const void *drvdata,
@@ -757,8 +743,6 @@ static int ina238_probe(struct i2c_client *client)
 	/* set the device type */
 	data->config = &ina238_config[chip];
 
-	mutex_init(&data->config_lock);
-
 	data->regmap = devm_regmap_init_i2c(client, &ina238_regmap_config);
 	if (IS_ERR(data->regmap)) {
 		dev_err(dev, "failed to allocate register map\n");
-- 
2.45.2

[PATCH 14/29] hwmon: (lm95241) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lm95241.c | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/drivers/hwmon/lm95241.c b/drivers/hwmon/lm95241.c
index cad0a0ff8416..456381b0938e 100644
--- a/drivers/hwmon/lm95241.c
+++ b/drivers/hwmon/lm95241.c
@@ -15,7 +15,6 @@
 #include <linux/jiffies.h>
 #include <linux/hwmon.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/slab.h>
 
 #define DEVNAME "lm95241"
@@ -75,7 +74,6 @@ static const u8 lm95241_reg_address[] = {
 /* Client data (each client gets its own) */
 struct lm95241_data {
 	struct i2c_client *client;
-	struct mutex update_lock;
 	unsigned long last_updated;	/* in jiffies */
 	unsigned long interval;		/* in milli-seconds */
 	bool valid;		/* false until following fields are valid */
@@ -102,8 +100,6 @@ static struct lm95241_data *lm95241_update_device(struct device *dev)
 	struct lm95241_data *data = dev_get_drvdata(dev);
 	struct i2c_client *client = data->client;
 
-	mutex_lock(&data->update_lock);
-
 	if (time_after(jiffies, data->last_updated
 		       + msecs_to_jiffies(data->interval)) ||
 	    !data->valid) {
@@ -120,9 +116,6 @@ static struct lm95241_data *lm95241_update_device(struct device *dev)
 		data->last_updated = jiffies;
 		data->valid = true;
 	}
-
-	mutex_unlock(&data->update_lock);
-
 	return data;
 }
 
@@ -204,8 +197,6 @@ static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
 	u8 config;
 	int ret;
 
-	mutex_lock(&data->update_lock);
-
 	switch (attr) {
 	case hwmon_chip_update_interval:
 		config = data->config & ~CFG_CRMASK;
@@ -231,7 +222,6 @@ static int lm95241_write_chip(struct device *dev, u32 attr, int channel,
 		ret = -EOPNOTSUPP;
 		break;
 	}
-	mutex_unlock(&data->update_lock);
 	return ret;
 }
 
@@ -242,8 +232,6 @@ static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
 	struct i2c_client *client = data->client;
 	int ret;
 
-	mutex_lock(&data->update_lock);
-
 	switch (attr) {
 	case hwmon_temp_min:
 		if (channel == 1) {
@@ -313,9 +301,6 @@ static int lm95241_write_temp(struct device *dev, u32 attr, int channel,
 		ret = -EOPNOTSUPP;
 		break;
 	}
-
-	mutex_unlock(&data->update_lock);
-
 	return ret;
 }
 
@@ -443,7 +428,6 @@ static int lm95241_probe(struct i2c_client *client)
 		return -ENOMEM;
 
 	data->client = client;
-	mutex_init(&data->update_lock);
 
 	/* Initialize the LM95241 chip */
 	lm95241_init_client(client, data);
-- 
2.45.2

[PATCH 15/29] hwmon: (aht10) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/aht10.c | 24 +++---------------------
 1 file changed, 3 insertions(+), 21 deletions(-)

diff --git a/drivers/hwmon/aht10.c b/drivers/hwmon/aht10.c
index d1c55e2eb479..8b90b661c393 100644
--- a/drivers/hwmon/aht10.c
+++ b/drivers/hwmon/aht10.c
@@ -60,8 +60,6 @@ MODULE_DEVICE_TABLE(i2c, aht10_id);
 /**
  *   struct aht10_data - All the data required to operate an AHT10/AHT20 chip
  *   @client: the i2c client associated with the AHT10/AHT20
- *   @lock: a mutex that is used to prevent parallel access to the
- *          i2c client
  *   @min_poll_interval: the minimum poll interval
  *                   While the poll rate limit is not 100% necessary,
  *                   the datasheet recommends that a measurement
@@ -81,11 +79,6 @@ MODULE_DEVICE_TABLE(i2c, aht10_id);
 
 struct aht10_data {
 	struct i2c_client *client;
-	/*
-	 * Prevent simultaneous access to the i2c
-	 * client and previous_poll_time
-	 */
-	struct mutex lock;
 	ktime_t min_poll_interval;
 	ktime_t previous_poll_time;
 	int temperature;
@@ -168,32 +161,24 @@ static int aht10_read_values(struct aht10_data *data)
 	u8 raw_data[AHT20_MEAS_SIZE];
 	struct i2c_client *client = data->client;
 
-	mutex_lock(&data->lock);
-	if (!aht10_polltime_expired(data)) {
-		mutex_unlock(&data->lock);
+	if (!aht10_polltime_expired(data))
 		return 0;
-	}
 
 	res = i2c_master_send(client, cmd_meas, sizeof(cmd_meas));
-	if (res < 0) {
-		mutex_unlock(&data->lock);
+	if (res < 0)
 		return res;
-	}
 
 	usleep_range(AHT10_MEAS_DELAY, AHT10_MEAS_DELAY + AHT10_DELAY_EXTRA);
 
 	res = i2c_master_recv(client, raw_data, data->meas_size);
 	if (res != data->meas_size) {
-		mutex_unlock(&data->lock);
 		if (res >= 0)
 			return -ENODATA;
 		return res;
 	}
 
-	if (data->crc8 && crc8_check(raw_data, data->meas_size)) {
-		mutex_unlock(&data->lock);
+	if (data->crc8 && crc8_check(raw_data, data->meas_size))
 		return -EIO;
-	}
 
 	hum =   ((u32)raw_data[1] << 12u) |
 		((u32)raw_data[2] << 4u) |
@@ -210,7 +195,6 @@ static int aht10_read_values(struct aht10_data *data)
 	data->humidity = hum;
 	data->previous_poll_time = ktime_get_boottime();
 
-	mutex_unlock(&data->lock);
 	return 0;
 }
 
@@ -358,8 +342,6 @@ static int aht10_probe(struct i2c_client *client)
 		break;
 	}
 
-	mutex_init(&data->lock);
-
 	res = aht10_init(data);
 	if (res < 0)
 		return res;
-- 
2.45.2

[PATCH 16/29] hwmon: (adt7411) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/adt7411.c | 59 +++++++++++------------------------------
 1 file changed, 16 insertions(+), 43 deletions(-)

diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
index 08d0effd97f7..b9991a69e6c6 100644
--- a/drivers/hwmon/adt7411.c
+++ b/drivers/hwmon/adt7411.c
@@ -11,7 +11,6 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 #include <linux/jiffies.h>
 #include <linux/i2c.h>
 #include <linux/hwmon.h>
@@ -99,8 +98,6 @@ static const u8 adt7411_in_alarm_bits[] = {
 };
 
 struct adt7411_data {
-	struct mutex device_lock;	/* for "atomic" device accesses */
-	struct mutex update_lock;
 	unsigned long next_update;
 	long vref_cached;
 	struct i2c_client *client;
@@ -110,55 +107,41 @@ struct adt7411_data {
 /*
  * When reading a register containing (up to 4) lsb, all associated
  * msb-registers get locked by the hardware. After _one_ of those msb is read,
- * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
- * is protected here with a mutex, too.
+ * _all_ are unlocked.
  */
 static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
-				u8 msb_reg, u8 lsb_shift)
+			       u8 msb_reg, u8 lsb_shift)
 {
-	struct adt7411_data *data = i2c_get_clientdata(client);
 	int val, tmp;
 
-	mutex_lock(&data->device_lock);
-
 	val = i2c_smbus_read_byte_data(client, lsb_reg);
 	if (val < 0)
-		goto exit_unlock;
+		return val;
 
 	tmp = (val >> lsb_shift) & 3;
 	val = i2c_smbus_read_byte_data(client, msb_reg);
+	if (val < 0)
+		return val;
 
-	if (val >= 0)
-		val = (val << 2) | tmp;
-
- exit_unlock:
-	mutex_unlock(&data->device_lock);
-
+	val = (val << 2) | tmp;
 	return val;
 }
 
 static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
-				bool flag)
+			      bool flag)
 {
-	struct adt7411_data *data = i2c_get_clientdata(client);
 	int ret, val;
 
-	mutex_lock(&data->device_lock);
-
 	ret = i2c_smbus_read_byte_data(client, reg);
 	if (ret < 0)
-		goto exit_unlock;
+		return ret;
 
 	if (flag)
 		val = ret | bit;
 	else
 		val = ret & ~bit;
 
-	ret = i2c_smbus_write_byte_data(client, reg, val);
-
- exit_unlock:
-	mutex_unlock(&data->device_lock);
-	return ret;
+	return i2c_smbus_write_byte_data(client, reg, val);
 }
 
 static ssize_t adt7411_show_bit(struct device *dev,
@@ -186,12 +169,11 @@ static ssize_t adt7411_set_bit(struct device *dev,
 	if (ret || flag > 1)
 		return -EINVAL;
 
+	hwmon_lock(dev);
 	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
-
 	/* force update */
-	mutex_lock(&data->update_lock);
 	data->next_update = jiffies;
-	mutex_unlock(&data->update_lock);
+	hwmon_unlock(dev);
 
 	return ret < 0 ? ret : count;
 }
@@ -294,10 +276,9 @@ static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
 	int reg, lsb_reg, lsb_shift;
 	int nr = channel - 1;
 
-	mutex_lock(&data->update_lock);
 	ret = adt7411_update_vref(dev);
 	if (ret < 0)
-		goto exit_unlock;
+		return ret;
 
 	switch (attr) {
 	case hwmon_in_input:
@@ -307,7 +288,7 @@ static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
 					  ADT7411_REG_EXT_TEMP_AIN1_MSB + nr,
 					  lsb_shift);
 		if (ret < 0)
-			goto exit_unlock;
+			return ret;
 		*val = ret * data->vref_cached / 1024;
 		ret = 0;
 		break;
@@ -318,7 +299,7 @@ static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
 			: ADT7411_REG_IN_HIGH(channel);
 		ret = i2c_smbus_read_byte_data(client, reg);
 		if (ret < 0)
-			goto exit_unlock;
+			return ret;
 		*val = ret * data->vref_cached / 256;
 		ret = 0;
 		break;
@@ -329,8 +310,6 @@ static int adt7411_read_in_chan(struct device *dev, u32 attr, int channel,
 		ret = -EOPNOTSUPP;
 		break;
 	}
- exit_unlock:
-	mutex_unlock(&data->update_lock);
 	return ret;
 }
 
@@ -457,10 +436,9 @@ static int adt7411_write_in_chan(struct device *dev, u32 attr, int channel,
 	struct i2c_client *client = data->client;
 	int ret, reg;
 
-	mutex_lock(&data->update_lock);
 	ret = adt7411_update_vref(dev);
 	if (ret < 0)
-		goto exit_unlock;
+		return ret;
 	val = clamp_val(val, 0, 255 * data->vref_cached / 256);
 	val = DIV_ROUND_CLOSEST(val * 256, data->vref_cached);
 
@@ -472,13 +450,10 @@ static int adt7411_write_in_chan(struct device *dev, u32 attr, int channel,
 		reg = ADT7411_REG_IN_HIGH(channel);
 		break;
 	default:
-		ret = -EOPNOTSUPP;
-		goto exit_unlock;
+		return -EOPNOTSUPP;
 	}
 
 	ret = i2c_smbus_write_byte_data(client, reg, val);
- exit_unlock:
-	mutex_unlock(&data->update_lock);
 	return ret;
 }
 
@@ -679,8 +654,6 @@ static int adt7411_probe(struct i2c_client *client)
 
 	i2c_set_clientdata(client, data);
 	data->client = client;
-	mutex_init(&data->device_lock);
-	mutex_init(&data->update_lock);
 
 	ret = adt7411_init_device(data);
 	if (ret < 0)
-- 
2.45.2

Re: [PATCH 16/29] hwmon: (adt7411) Rely on subsystem locking

[Nuno Sá]

On Fri, 2025-10-17 at 06:02 -0700, Guenter Roeck wrote:
> Attribute access is now serialized in the hardware monitoring core,
> so locking in the driver code is no longer necessary. Drop it.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/hwmon/adt7411.c | 59 +++++++++++------------------------------
>  1 file changed, 16 insertions(+), 43 deletions(-)
> 
> diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
> index 08d0effd97f7..b9991a69e6c6 100644
> --- a/drivers/hwmon/adt7411.c
> +++ b/drivers/hwmon/adt7411.c
> @@ -11,7 +11,6 @@
>  #include <linux/module.h>
>  #include <linux/init.h>
>  #include <linux/err.h>
> -#include <linux/mutex.h>
>  #include <linux/jiffies.h>
>  #include <linux/i2c.h>
>  #include <linux/hwmon.h>
> @@ -99,8 +98,6 @@ static const u8 adt7411_in_alarm_bits[] = {
>  };
>  
>  struct adt7411_data {
> -	struct mutex device_lock;	/* for "atomic" device accesses */
> -	struct mutex update_lock;
>  	unsigned long next_update;
>  	long vref_cached;
>  	struct i2c_client *client;
> @@ -110,55 +107,41 @@ struct adt7411_data {
>  /*
>   * When reading a register containing (up to 4) lsb, all associated
>   * msb-registers get locked by the hardware. After _one_ of those msb is
> read,
> - * _all_ are unlocked. In order to use this locking correctly, reading
> lsb/msb
> - * is protected here with a mutex, too.
> + * _all_ are unlocked.
>   */
>  static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
> -				u8 msb_reg, u8 lsb_shift)
> +			       u8 msb_reg, u8 lsb_shift)
>  {
> -	struct adt7411_data *data = i2c_get_clientdata(client);
>  	int val, tmp;
>  
> -	mutex_lock(&data->device_lock);
> -
>  	val = i2c_smbus_read_byte_data(client, lsb_reg);
>  	if (val < 0)
> -		goto exit_unlock;
> +		return val;
>  
>  	tmp = (val >> lsb_shift) & 3;
>  	val = i2c_smbus_read_byte_data(client, msb_reg);
> +	if (val < 0)
> +		return val;
>  
> -	if (val >= 0)
> -		val = (val << 2) | tmp;
> -
> - exit_unlock:
> -	mutex_unlock(&data->device_lock);
> -
> +	val = (val << 2) | tmp;
>  	return val;
>  }
>  
>  static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
> -				bool flag)
> +			      bool flag)
>  {
> -	struct adt7411_data *data = i2c_get_clientdata(client);
>  	int ret, val;
>  
> -	mutex_lock(&data->device_lock);
> -
>  	ret = i2c_smbus_read_byte_data(client, reg);
>  	if (ret < 0)
> -		goto exit_unlock;
> +		return ret;
>  
>  	if (flag)
>  		val = ret | bit;
>  	else
>  		val = ret & ~bit;
>  
> -	ret = i2c_smbus_write_byte_data(client, reg, val);
> -
> - exit_unlock:
> -	mutex_unlock(&data->device_lock);
> -	return ret;
> +	return i2c_smbus_write_byte_data(client, reg, val);
>  }
>  
>  static ssize_t adt7411_show_bit(struct device *dev,
> @@ -186,12 +169,11 @@ static ssize_t adt7411_set_bit(struct device *dev,
>  	if (ret || flag > 1)
>  		return -EINVAL;
>  
> +	hwmon_lock(dev);
>  	ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
> -
>  	/* force update */
> -	mutex_lock(&data->update_lock);
>  	data->next_update = jiffies;
> -	mutex_unlock(&data->update_lock);
> +	hwmon_unlock(dev);
>  
>  	return ret < 0 ? ret : count;
>  }
> @@ -294,10 +276,9 @@ static int adt7411_read_in_chan(struct device *dev, u32
> attr, int channel,
>  	int reg, lsb_reg, lsb_shift;
>  	int nr = channel - 1;
>  
> -	mutex_lock(&data->update_lock);
>  	ret = adt7411_update_vref(dev);
>  	if (ret < 0)
> -		goto exit_unlock;
> +		return ret;
>  
>  	switch (attr) {
>  	case hwmon_in_input:
> @@ -307,7 +288,7 @@ static int adt7411_read_in_chan(struct device *dev, u32
> attr, int channel,
>  					  ADT7411_REG_EXT_TEMP_AIN1_MSB + nr,
>  					  lsb_shift);
>  		if (ret < 0)
> -			goto exit_unlock;
> +			return ret;
>  		*val = ret * data->vref_cached / 1024;
>  		ret = 0;
>  		break;
> @@ -318,7 +299,7 @@ static int adt7411_read_in_chan(struct device *dev, u32
> attr, int channel,
>  			: ADT7411_REG_IN_HIGH(channel);
>  		ret = i2c_smbus_read_byte_data(client, reg);
>  		if (ret < 0)
> -			goto exit_unlock;
> +			return ret;
>  		*val = ret * data->vref_cached / 256;
>  		ret = 0;
>  		break;
> @@ -329,8 +310,6 @@ static int adt7411_read_in_chan(struct device *dev, u32
> attr, int channel,
>  		ret = -EOPNOTSUPP;
>  		break;
>  	}
> - exit_unlock:
> -	mutex_unlock(&data->update_lock);
>  	return ret;
>  }
>  
> @@ -457,10 +436,9 @@ static int adt7411_write_in_chan(struct device *dev, u32
> attr, int channel,
>  	struct i2c_client *client = data->client;
>  	int ret, reg;
>  
> -	mutex_lock(&data->update_lock);
>  	ret = adt7411_update_vref(dev);
>  	if (ret < 0)
> -		goto exit_unlock;
> +		return ret;
>  	val = clamp_val(val, 0, 255 * data->vref_cached / 256);
>  	val = DIV_ROUND_CLOSEST(val * 256, data->vref_cached);
>  
> @@ -472,13 +450,10 @@ static int adt7411_write_in_chan(struct device *dev, u32
> attr, int channel,
>  		reg = ADT7411_REG_IN_HIGH(channel);
>  		break;
>  	default:
> -		ret = -EOPNOTSUPP;
> -		goto exit_unlock;
> +		return -EOPNOTSUPP;
>  	}
>  
>  	ret = i2c_smbus_write_byte_data(client, reg, val);
> - exit_unlock:
> -	mutex_unlock(&data->update_lock);
>  	return ret;
>  }
>  
> @@ -679,8 +654,6 @@ static int adt7411_probe(struct i2c_client *client)
>  
>  	i2c_set_clientdata(client, data);
>  	data->client = client;
> -	mutex_init(&data->device_lock);
> -	mutex_init(&data->update_lock);
>  
>  	ret = adt7411_init_device(data);
>  	if (ret < 0)

[PATCH 17/29] hwmon: (ltc2947-core) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ltc2947-core.c | 32 +++++---------------------------
 1 file changed, 5 insertions(+), 27 deletions(-)

diff --git a/drivers/hwmon/ltc2947-core.c b/drivers/hwmon/ltc2947-core.c
index 90f70f732b41..ad7120d1e469 100644
--- a/drivers/hwmon/ltc2947-core.c
+++ b/drivers/hwmon/ltc2947-core.c
@@ -120,12 +120,6 @@
 struct ltc2947_data {
 	struct regmap *map;
 	struct device *dev;
-	/*
-	 * The mutex is needed because the device has 2 memory pages. When
-	 * reading/writing the correct page needs to be set so that, the
-	 * complete sequence select_page->read/write needs to be protected.
-	 */
-	struct mutex lock;
 	u32 lsb_energy;
 	bool gpio_out;
 };
@@ -181,13 +175,9 @@ static int ltc2947_val_read(struct ltc2947_data *st, const u8 reg,
 	int ret;
 	u64 __val = 0;
 
-	mutex_lock(&st->lock);
-
 	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
-	if (ret) {
-		mutex_unlock(&st->lock);
+	if (ret)
 		return ret;
-	}
 
 	dev_dbg(st->dev, "Read val, reg:%02X, p:%d sz:%zu\n", reg, page,
 		size);
@@ -207,8 +197,6 @@ static int ltc2947_val_read(struct ltc2947_data *st, const u8 reg,
 		break;
 	}
 
-	mutex_unlock(&st->lock);
-
 	if (ret)
 		return ret;
 
@@ -242,13 +230,10 @@ static int ltc2947_val_write(struct ltc2947_data *st, const u8 reg,
 {
 	int ret;
 
-	mutex_lock(&st->lock);
 	/* set device on correct page */
 	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
-	if (ret) {
-		mutex_unlock(&st->lock);
+	if (ret)
 		return ret;
-	}
 
 	dev_dbg(st->dev, "Write val, r:%02X, p:%d, sz:%zu, val:%016llX\n",
 		reg, page, size, val);
@@ -265,8 +250,6 @@ static int ltc2947_val_write(struct ltc2947_data *st, const u8 reg,
 		break;
 	}
 
-	mutex_unlock(&st->lock);
-
 	return ret;
 }
 
@@ -295,11 +278,9 @@ static int ltc2947_alarm_read(struct ltc2947_data *st, const u8 reg,
 
 	memset(alarms, 0, sizeof(alarms));
 
-	mutex_lock(&st->lock);
-
 	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, LTC2947_PAGE0);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	dev_dbg(st->dev, "Read alarm, reg:%02X, mask:%02X\n", reg, mask);
 	/*
@@ -310,13 +291,11 @@ static int ltc2947_alarm_read(struct ltc2947_data *st, const u8 reg,
 	ret = regmap_bulk_read(st->map, LTC2947_REG_STATUS, alarms,
 			       sizeof(alarms));
 	if (ret)
-		goto unlock;
+		return ret;
 
 	/* get the alarm */
 	*val = !!(alarms[offset] & mask);
-unlock:
-	mutex_unlock(&st->lock);
-	return ret;
+	return 0;
 }
 
 static int ltc2947_read_temp(struct device *dev, const u32 attr, long *val,
@@ -1100,7 +1079,6 @@ int ltc2947_core_probe(struct regmap *map, const char *name)
 	st->map = map;
 	st->dev = dev;
 	dev_set_drvdata(dev, st);
-	mutex_init(&st->lock);
 
 	ret = ltc2947_setup(st);
 	if (ret)
-- 
2.45.2

Re: [PATCH 17/29] hwmon: (ltc2947-core) Rely on subsystem locking

[Nuno Sá]

On Fri, 2025-10-17 at 06:02 -0700, Guenter Roeck wrote:
> Attribute access is now serialized in the hardware monitoring core,
> so locking in the driver code is no longer necessary. Drop it.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/hwmon/ltc2947-core.c | 32 +++++---------------------------
>  1 file changed, 5 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/hwmon/ltc2947-core.c b/drivers/hwmon/ltc2947-core.c
> index 90f70f732b41..ad7120d1e469 100644
> --- a/drivers/hwmon/ltc2947-core.c
> +++ b/drivers/hwmon/ltc2947-core.c
> @@ -120,12 +120,6 @@
>  struct ltc2947_data {
>  	struct regmap *map;
>  	struct device *dev;
> -	/*
> -	 * The mutex is needed because the device has 2 memory pages. When
> -	 * reading/writing the correct page needs to be set so that, the
> -	 * complete sequence select_page->read/write needs to be protected.
> -	 */
> -	struct mutex lock;
>  	u32 lsb_energy;
>  	bool gpio_out;
>  };
> @@ -181,13 +175,9 @@ static int ltc2947_val_read(struct ltc2947_data *st,
> const u8 reg,
>  	int ret;
>  	u64 __val = 0;
>  
> -	mutex_lock(&st->lock);
> -
>  	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
> -	if (ret) {
> -		mutex_unlock(&st->lock);
> +	if (ret)
>  		return ret;
> -	}
>  
>  	dev_dbg(st->dev, "Read val, reg:%02X, p:%d sz:%zu\n", reg, page,
>  		size);
> @@ -207,8 +197,6 @@ static int ltc2947_val_read(struct ltc2947_data *st, const
> u8 reg,
>  		break;
>  	}
>  
> -	mutex_unlock(&st->lock);
> -
>  	if (ret)
>  		return ret;
>  
> @@ -242,13 +230,10 @@ static int ltc2947_val_write(struct ltc2947_data *st,
> const u8 reg,
>  {
>  	int ret;
>  
> -	mutex_lock(&st->lock);
>  	/* set device on correct page */
>  	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, page);
> -	if (ret) {
> -		mutex_unlock(&st->lock);
> +	if (ret)
>  		return ret;
> -	}
>  
>  	dev_dbg(st->dev, "Write val, r:%02X, p:%d, sz:%zu, val:%016llX\n",
>  		reg, page, size, val);
> @@ -265,8 +250,6 @@ static int ltc2947_val_write(struct ltc2947_data *st,
> const u8 reg,
>  		break;
>  	}
>  
> -	mutex_unlock(&st->lock);
> -
>  	return ret;
>  }
>  
> @@ -295,11 +278,9 @@ static int ltc2947_alarm_read(struct ltc2947_data *st,
> const u8 reg,
>  
>  	memset(alarms, 0, sizeof(alarms));
>  
> -	mutex_lock(&st->lock);
> -
>  	ret = regmap_write(st->map, LTC2947_REG_PAGE_CTRL, LTC2947_PAGE0);
>  	if (ret)
> -		goto unlock;
> +		return ret;
>  
>  	dev_dbg(st->dev, "Read alarm, reg:%02X, mask:%02X\n", reg, mask);
>  	/*
> @@ -310,13 +291,11 @@ static int ltc2947_alarm_read(struct ltc2947_data *st,
> const u8 reg,
>  	ret = regmap_bulk_read(st->map, LTC2947_REG_STATUS, alarms,
>  			       sizeof(alarms));
>  	if (ret)
> -		goto unlock;
> +		return ret;
>  
>  	/* get the alarm */
>  	*val = !!(alarms[offset] & mask);
> -unlock:
> -	mutex_unlock(&st->lock);
> -	return ret;
> +	return 0;
>  }
>  
>  static int ltc2947_read_temp(struct device *dev, const u32 attr, long *val,
> @@ -1100,7 +1079,6 @@ int ltc2947_core_probe(struct regmap *map, const char
> *name)
>  	st->map = map;
>  	st->dev = dev;
>  	dev_set_drvdata(dev, st);
> -	mutex_init(&st->lock);
>  
>  	ret = ltc2947_setup(st);
>  	if (ret)

[PATCH 18/29] hwmon: (peci) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/peci/common.h   |  3 --
 drivers/hwmon/peci/cputemp.c  | 72 +++++++++--------------------------
 drivers/hwmon/peci/dimmtemp.c | 17 ++-------
 3 files changed, 23 insertions(+), 69 deletions(-)

diff --git a/drivers/hwmon/peci/common.h b/drivers/hwmon/peci/common.h
index 734506b0eca2..92a7ee1925bc 100644
--- a/drivers/hwmon/peci/common.h
+++ b/drivers/hwmon/peci/common.h
@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 /* Copyright (c) 2021 Intel Corporation */
 
-#include <linux/mutex.h>
 #include <linux/types.h>
 
 #ifndef __PECI_HWMON_COMMON_H
@@ -13,12 +12,10 @@
  * struct peci_sensor_state - PECI state information
  * @valid: flag to indicate the sensor value is valid
  * @last_updated: time of the last update in jiffies
- * @lock: mutex to protect sensor access
  */
 struct peci_sensor_state {
 	bool valid;
 	unsigned long last_updated;
-	struct mutex lock; /* protect sensor access */
 };
 
 /**
diff --git a/drivers/hwmon/peci/cputemp.c b/drivers/hwmon/peci/cputemp.c
index b350c9a76894..b2fc936851e1 100644
--- a/drivers/hwmon/peci/cputemp.c
+++ b/drivers/hwmon/peci/cputemp.c
@@ -116,11 +116,9 @@ static int get_temp_target(struct peci_cputemp *priv, enum peci_temp_target_type
 {
 	int ret;
 
-	mutex_lock(&priv->temp.target.state.lock);
-
 	ret = update_temp_target(priv);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	switch (type) {
 	case tcontrol_type:
@@ -139,9 +137,6 @@ static int get_temp_target(struct peci_cputemp *priv, enum peci_temp_target_type
 		ret = -EOPNOTSUPP;
 		break;
 	}
-unlock:
-	mutex_unlock(&priv->temp.target.state.lock);
-
 	return ret;
 }
 
@@ -177,26 +172,23 @@ static s32 dts_eight_dot_eight_to_millidegree(u16 val)
 
 static int get_die_temp(struct peci_cputemp *priv, long *val)
 {
-	int ret = 0;
 	long tjmax;
 	u16 temp;
+	int ret;
 
-	mutex_lock(&priv->temp.die.state.lock);
 	if (!peci_sensor_need_update(&priv->temp.die.state))
 		goto skip_update;
 
 	ret = peci_temp_read(priv->peci_dev, &temp);
 	if (ret)
-		goto err_unlock;
+		return ret;
 
-	if (!dts_valid(temp)) {
-		ret = -EIO;
-		goto err_unlock;
-	}
+	if (!dts_valid(temp))
+		return -EIO;
 
 	ret = get_temp_target(priv, tjmax_type, &tjmax);
 	if (ret)
-		goto err_unlock;
+		return ret;
 
 	priv->temp.die.value = (s32)tjmax + dts_ten_dot_six_to_millidegree(temp);
 
@@ -204,35 +196,30 @@ static int get_die_temp(struct peci_cputemp *priv, long *val)
 
 skip_update:
 	*val = priv->temp.die.value;
-err_unlock:
-	mutex_unlock(&priv->temp.die.state.lock);
-	return ret;
+	return 0;
 }
 
 static int get_dts(struct peci_cputemp *priv, long *val)
 {
-	int ret = 0;
 	u16 thermal_margin;
 	long tcontrol;
 	u32 pcs;
+	int ret;
 
-	mutex_lock(&priv->temp.dts.state.lock);
 	if (!peci_sensor_need_update(&priv->temp.dts.state))
 		goto skip_update;
 
 	ret = peci_pcs_read(priv->peci_dev, PECI_PCS_THERMAL_MARGIN, 0, &pcs);
 	if (ret)
-		goto err_unlock;
+		return ret;
 
 	thermal_margin = FIELD_GET(DTS_MARGIN_MASK, pcs);
-	if (!dts_valid(thermal_margin)) {
-		ret = -EIO;
-		goto err_unlock;
-	}
+	if (!dts_valid(thermal_margin))
+		return -EIO;
 
 	ret = get_temp_target(priv, tcontrol_type, &tcontrol);
 	if (ret)
-		goto err_unlock;
+		return ret;
 
 	/* Note that the tcontrol should be available before calling it */
 	priv->temp.dts.value =
@@ -242,35 +229,30 @@ static int get_dts(struct peci_cputemp *priv, long *val)
 
 skip_update:
 	*val = priv->temp.dts.value;
-err_unlock:
-	mutex_unlock(&priv->temp.dts.state.lock);
-	return ret;
+	return 0;
 }
 
 static int get_core_temp(struct peci_cputemp *priv, int core_index, long *val)
 {
-	int ret = 0;
 	u16 core_dts_margin;
 	long tjmax;
 	u32 pcs;
+	int ret;
 
-	mutex_lock(&priv->temp.core[core_index].state.lock);
 	if (!peci_sensor_need_update(&priv->temp.core[core_index].state))
 		goto skip_update;
 
 	ret = peci_pcs_read(priv->peci_dev, PECI_PCS_MODULE_TEMP, core_index, &pcs);
 	if (ret)
-		goto err_unlock;
+		return ret;
 
 	core_dts_margin = FIELD_GET(PCS_MODULE_TEMP_MASK, pcs);
-	if (!dts_valid(core_dts_margin)) {
-		ret = -EIO;
-		goto err_unlock;
-	}
+	if (!dts_valid(core_dts_margin))
+		return -EIO;
 
 	ret = get_temp_target(priv, tjmax_type, &tjmax);
 	if (ret)
-		goto err_unlock;
+		return ret;
 
 	/* Note that the tjmax should be available before calling it */
 	priv->temp.core[core_index].value =
@@ -280,9 +262,7 @@ static int get_core_temp(struct peci_cputemp *priv, int core_index, long *val)
 
 skip_update:
 	*val = priv->temp.core[core_index].value;
-err_unlock:
-	mutex_unlock(&priv->temp.core[core_index].state.lock);
-	return ret;
+	return 0;
 }
 
 static int cputemp_read_string(struct device *dev, enum hwmon_sensor_types type,
@@ -431,18 +411,6 @@ static void check_resolved_cores(struct peci_cputemp *priv)
 		bitmap_zero(priv->core_mask, CORE_NUMS_MAX);
 }
 
-static void sensor_init(struct peci_cputemp *priv)
-{
-	int i;
-
-	mutex_init(&priv->temp.target.state.lock);
-	mutex_init(&priv->temp.die.state.lock);
-	mutex_init(&priv->temp.dts.state.lock);
-
-	for_each_set_bit(i, priv->core_mask, CORE_NUMS_MAX)
-		mutex_init(&priv->temp.core[i].state.lock);
-}
-
 static const struct hwmon_ops peci_cputemp_ops = {
 	.is_visible = cputemp_is_visible,
 	.read_string = cputemp_read_string,
@@ -507,8 +475,6 @@ static int peci_cputemp_probe(struct auxiliary_device *adev,
 
 	check_resolved_cores(priv);
 
-	sensor_init(priv);
-
 	hwmon_dev = devm_hwmon_device_register_with_info(priv->dev, priv->name,
 							 priv, &peci_cputemp_chip_info, NULL);
 
diff --git a/drivers/hwmon/peci/dimmtemp.c b/drivers/hwmon/peci/dimmtemp.c
index a281476c7a31..bd3e8715dfec 100644
--- a/drivers/hwmon/peci/dimmtemp.c
+++ b/drivers/hwmon/peci/dimmtemp.c
@@ -96,16 +96,15 @@ static int get_dimm_temp(struct peci_dimmtemp *priv, int dimm_no, long *val)
 {
 	int dimm_order = dimm_no % priv->gen_info->dimm_idx_max;
 	int chan_rank = dimm_no / priv->gen_info->dimm_idx_max;
-	int ret = 0;
 	u32 data;
+	int ret;
 
-	mutex_lock(&priv->dimm[dimm_no].temp.state.lock);
 	if (!peci_sensor_need_update(&priv->dimm[dimm_no].temp.state))
 		goto skip_update;
 
 	ret = peci_pcs_read(priv->peci_dev, PECI_PCS_DDR_DIMM_TEMP, chan_rank, &data);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	priv->dimm[dimm_no].temp.value = __dimm_temp(data, dimm_order) * MILLIDEGREE_PER_DEGREE;
 
@@ -113,9 +112,7 @@ static int get_dimm_temp(struct peci_dimmtemp *priv, int dimm_no, long *val)
 
 skip_update:
 	*val = priv->dimm[dimm_no].temp.value;
-unlock:
-	mutex_unlock(&priv->dimm[dimm_no].temp.state.lock);
-	return ret;
+	return 0;
 }
 
 static int update_thresholds(struct peci_dimmtemp *priv, int dimm_no)
@@ -145,10 +142,9 @@ static int get_dimm_thresholds(struct peci_dimmtemp *priv, enum peci_dimm_thresh
 {
 	int ret;
 
-	mutex_lock(&priv->dimm[dimm_no].thresholds.state.lock);
 	ret = update_thresholds(priv, dimm_no);
 	if (ret)
-		goto unlock;
+		return ret;
 
 	switch (type) {
 	case temp_max_type:
@@ -161,9 +157,6 @@ static int get_dimm_thresholds(struct peci_dimmtemp *priv, enum peci_dimm_thresh
 		ret = -EOPNOTSUPP;
 		break;
 	}
-unlock:
-	mutex_unlock(&priv->dimm[dimm_no].thresholds.state.lock);
-
 	return ret;
 }
 
@@ -349,8 +342,6 @@ static int create_dimm_temp_info(struct peci_dimmtemp *priv)
 		ret = create_dimm_temp_label(priv, i);
 		if (ret)
 			return ret;
-		mutex_init(&priv->dimm[i].thresholds.state.lock);
-		mutex_init(&priv->dimm[i].temp.state.lock);
 	}
 
 	dev = devm_hwmon_device_register_with_info(priv->dev, priv->name, priv,
-- 
2.45.2

[PATCH 19/29] hwmon: (adt7x10) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/adt7x10.c | 27 +++++----------------------
 1 file changed, 5 insertions(+), 22 deletions(-)

diff --git a/drivers/hwmon/adt7x10.c b/drivers/hwmon/adt7x10.c
index 2d329391ed3f..d003ee3ebf06 100644
--- a/drivers/hwmon/adt7x10.c
+++ b/drivers/hwmon/adt7x10.c
@@ -15,7 +15,6 @@
 #include <linux/jiffies.h>
 #include <linux/hwmon.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
 #include <linux/regmap.h>
@@ -55,7 +54,6 @@
 /* Each client has this additional data */
 struct adt7x10_data {
 	struct regmap		*regmap;
-	struct mutex		update_lock;
 	u8			config;
 	u8			oldconfig;
 	bool			valid;		/* true if temperature valid */
@@ -137,17 +135,13 @@ static int adt7x10_temp_read(struct adt7x10_data *data, int index, long *val)
 	unsigned int regval;
 	int ret;
 
-	mutex_lock(&data->update_lock);
 	if (index == adt7x10_temperature && !data->valid) {
 		/* wait for valid temperature */
 		ret = adt7x10_temp_ready(data->regmap);
-		if (ret) {
-			mutex_unlock(&data->update_lock);
+		if (ret)
 			return ret;
-		}
 		data->valid = true;
 	}
-	mutex_unlock(&data->update_lock);
 
 	ret = regmap_read(data->regmap, ADT7X10_REG_TEMP[index], &regval);
 	if (ret)
@@ -159,13 +153,8 @@ static int adt7x10_temp_read(struct adt7x10_data *data, int index, long *val)
 
 static int adt7x10_temp_write(struct adt7x10_data *data, int index, long temp)
 {
-	int ret;
-
-	mutex_lock(&data->update_lock);
-	ret = regmap_write(data->regmap, ADT7X10_REG_TEMP[index],
-			   ADT7X10_TEMP_TO_REG(temp));
-	mutex_unlock(&data->update_lock);
-	return ret;
+	return regmap_write(data->regmap, ADT7X10_REG_TEMP[index],
+			    ADT7X10_TEMP_TO_REG(temp));
 }
 
 static int adt7x10_hyst_read(struct adt7x10_data *data, int index, long *val)
@@ -197,22 +186,17 @@ static int adt7x10_hyst_write(struct adt7x10_data *data, long hyst)
 	unsigned int regval;
 	int limit, ret;
 
-	mutex_lock(&data->update_lock);
-
 	/* convert absolute hysteresis value to a 4 bit delta value */
 	ret = regmap_read(data->regmap, ADT7X10_T_ALARM_HIGH, &regval);
 	if (ret < 0)
-		goto abort;
+		return ret;
 
 	limit = ADT7X10_REG_TO_TEMP(data, regval);
 
 	hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
 	regval = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000), 0,
 			   ADT7X10_T_HYST_MASK);
-	ret = regmap_write(data->regmap, ADT7X10_T_HYST, regval);
-abort:
-	mutex_unlock(&data->update_lock);
-	return ret;
+	return regmap_write(data->regmap, ADT7X10_T_HYST, regval);
 }
 
 static int adt7x10_alarm_read(struct adt7x10_data *data, int index, long *val)
@@ -344,7 +328,6 @@ int adt7x10_probe(struct device *dev, const char *name, int irq,
 	data->regmap = regmap;
 
 	dev_set_drvdata(dev, data);
-	mutex_init(&data->update_lock);
 
 	/* configure as specified */
 	ret = regmap_read(regmap, ADT7X10_CONFIG, &config);
-- 
2.45.2

Re: [PATCH 19/29] hwmon: (adt7x10) Rely on subsystem locking

[Nuno Sá]

On Fri, 2025-10-17 at 06:02 -0700, Guenter Roeck wrote:
> Attribute access is now serialized in the hardware monitoring core,
> so locking in the driver code is no longer necessary. Drop it.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/hwmon/adt7x10.c | 27 +++++----------------------
>  1 file changed, 5 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/hwmon/adt7x10.c b/drivers/hwmon/adt7x10.c
> index 2d329391ed3f..d003ee3ebf06 100644
> --- a/drivers/hwmon/adt7x10.c
> +++ b/drivers/hwmon/adt7x10.c
> @@ -15,7 +15,6 @@
>  #include <linux/jiffies.h>
>  #include <linux/hwmon.h>
>  #include <linux/err.h>
> -#include <linux/mutex.h>
>  #include <linux/delay.h>
>  #include <linux/interrupt.h>
>  #include <linux/regmap.h>
> @@ -55,7 +54,6 @@
>  /* Each client has this additional data */
>  struct adt7x10_data {
>  	struct regmap		*regmap;
> -	struct mutex		update_lock;
>  	u8			config;
>  	u8			oldconfig;
>  	bool			valid;		/* true if temperature valid
> */
> @@ -137,17 +135,13 @@ static int adt7x10_temp_read(struct adt7x10_data *data,
> int index, long *val)
>  	unsigned int regval;
>  	int ret;
>  
> -	mutex_lock(&data->update_lock);
>  	if (index == adt7x10_temperature && !data->valid) {
>  		/* wait for valid temperature */
>  		ret = adt7x10_temp_ready(data->regmap);
> -		if (ret) {
> -			mutex_unlock(&data->update_lock);
> +		if (ret)
>  			return ret;
> -		}
>  		data->valid = true;
>  	}
> -	mutex_unlock(&data->update_lock);
>  
>  	ret = regmap_read(data->regmap, ADT7X10_REG_TEMP[index], &regval);
>  	if (ret)
> @@ -159,13 +153,8 @@ static int adt7x10_temp_read(struct adt7x10_data *data,
> int index, long *val)
>  
>  static int adt7x10_temp_write(struct adt7x10_data *data, int index, long
> temp)
>  {
> -	int ret;
> -
> -	mutex_lock(&data->update_lock);
> -	ret = regmap_write(data->regmap, ADT7X10_REG_TEMP[index],
> -			   ADT7X10_TEMP_TO_REG(temp));
> -	mutex_unlock(&data->update_lock);
> -	return ret;
> +	return regmap_write(data->regmap, ADT7X10_REG_TEMP[index],
> +			    ADT7X10_TEMP_TO_REG(temp));
>  }
>  
>  static int adt7x10_hyst_read(struct adt7x10_data *data, int index, long *val)
> @@ -197,22 +186,17 @@ static int adt7x10_hyst_write(struct adt7x10_data *data,
> long hyst)
>  	unsigned int regval;
>  	int limit, ret;
>  
> -	mutex_lock(&data->update_lock);
> -
>  	/* convert absolute hysteresis value to a 4 bit delta value */
>  	ret = regmap_read(data->regmap, ADT7X10_T_ALARM_HIGH, &regval);
>  	if (ret < 0)
> -		goto abort;
> +		return ret;
>  
>  	limit = ADT7X10_REG_TO_TEMP(data, regval);
>  
>  	hyst = clamp_val(hyst, ADT7X10_TEMP_MIN, ADT7X10_TEMP_MAX);
>  	regval = clamp_val(DIV_ROUND_CLOSEST(limit - hyst, 1000), 0,
>  			   ADT7X10_T_HYST_MASK);
> -	ret = regmap_write(data->regmap, ADT7X10_T_HYST, regval);
> -abort:
> -	mutex_unlock(&data->update_lock);
> -	return ret;
> +	return regmap_write(data->regmap, ADT7X10_T_HYST, regval);
>  }
>  
>  static int adt7x10_alarm_read(struct adt7x10_data *data, int index, long
> *val)
> @@ -344,7 +328,6 @@ int adt7x10_probe(struct device *dev, const char *name,
> int irq,
>  	data->regmap = regmap;
>  
>  	dev_set_drvdata(dev, data);
> -	mutex_init(&data->update_lock);
>  
>  	/* configure as specified */
>  	ret = regmap_read(regmap, ADT7X10_CONFIG, &config);

[PATCH 20/29] hwmon: (sfctemp) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/sfctemp.c | 36 ++++++++----------------------------
 1 file changed, 8 insertions(+), 28 deletions(-)

diff --git a/drivers/hwmon/sfctemp.c b/drivers/hwmon/sfctemp.c
index fb1da93383d7..b78b2c099a12 100644
--- a/drivers/hwmon/sfctemp.c
+++ b/drivers/hwmon/sfctemp.c
@@ -10,7 +10,6 @@
 #include <linux/hwmon.h>
 #include <linux/io.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/platform_device.h>
 #include <linux/reset.h>
@@ -49,8 +48,6 @@
 #define SFCTEMP_K1000	81100L
 
 struct sfctemp {
-	/* serialize access to hardware register and enabled below */
-	struct mutex lock;
 	void __iomem *regs;
 	struct clk *clk_sense;
 	struct clk *clk_bus;
@@ -92,15 +89,14 @@ static void sfctemp_stop(struct sfctemp *sfctemp)
 
 static int sfctemp_enable(struct sfctemp *sfctemp)
 {
-	int ret = 0;
+	int ret;
 
-	mutex_lock(&sfctemp->lock);
 	if (sfctemp->enabled)
-		goto done;
+		return 0;
 
 	ret = clk_prepare_enable(sfctemp->clk_bus);
 	if (ret)
-		goto err;
+		return ret;
 	ret = reset_control_deassert(sfctemp->rst_bus);
 	if (ret)
 		goto err_disable_bus;
@@ -115,9 +111,7 @@ static int sfctemp_enable(struct sfctemp *sfctemp)
 	sfctemp_power_up(sfctemp);
 	sfctemp_run(sfctemp);
 	sfctemp->enabled = true;
-done:
-	mutex_unlock(&sfctemp->lock);
-	return ret;
+	return 0;
 
 err_disable_sense:
 	clk_disable_unprepare(sfctemp->clk_sense);
@@ -125,16 +119,13 @@ static int sfctemp_enable(struct sfctemp *sfctemp)
 	reset_control_assert(sfctemp->rst_bus);
 err_disable_bus:
 	clk_disable_unprepare(sfctemp->clk_bus);
-err:
-	mutex_unlock(&sfctemp->lock);
 	return ret;
 }
 
 static int sfctemp_disable(struct sfctemp *sfctemp)
 {
-	mutex_lock(&sfctemp->lock);
 	if (!sfctemp->enabled)
-		goto done;
+		return 0;
 
 	sfctemp_stop(sfctemp);
 	sfctemp_power_down(sfctemp);
@@ -143,8 +134,6 @@ static int sfctemp_disable(struct sfctemp *sfctemp)
 	reset_control_assert(sfctemp->rst_bus);
 	clk_disable_unprepare(sfctemp->clk_bus);
 	sfctemp->enabled = false;
-done:
-	mutex_unlock(&sfctemp->lock);
 	return 0;
 }
 
@@ -155,22 +144,14 @@ static void sfctemp_disable_action(void *data)
 
 static int sfctemp_convert(struct sfctemp *sfctemp, long *val)
 {
-	int ret;
-
-	mutex_lock(&sfctemp->lock);
-	if (!sfctemp->enabled) {
-		ret = -ENODATA;
-		goto out;
-	}
+	if (!sfctemp->enabled)
+		return -ENODATA;
 
 	/* calculate temperature in milli Celcius */
 	*val = (long)((readl(sfctemp->regs) & SFCTEMP_DOUT_MSK) >> SFCTEMP_DOUT_POS)
 		* SFCTEMP_Y1000 / SFCTEMP_Z - SFCTEMP_K1000;
 
-	ret = 0;
-out:
-	mutex_unlock(&sfctemp->lock);
-	return ret;
+	return 0;
 }
 
 static umode_t sfctemp_is_visible(const void *data, enum hwmon_sensor_types type,
@@ -263,7 +244,6 @@ static int sfctemp_probe(struct platform_device *pdev)
 		return -ENOMEM;
 
 	dev_set_drvdata(dev, sfctemp);
-	mutex_init(&sfctemp->lock);
 
 	sfctemp->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(sfctemp->regs))
-- 
2.45.2

[PATCH 21/29] hwmon: (lochnagar-hwmon) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/lochnagar-hwmon.c | 18 +++---------------
 1 file changed, 3 insertions(+), 15 deletions(-)

diff --git a/drivers/hwmon/lochnagar-hwmon.c b/drivers/hwmon/lochnagar-hwmon.c
index 5202dddfd61e..c1ba72f6132e 100644
--- a/drivers/hwmon/lochnagar-hwmon.c
+++ b/drivers/hwmon/lochnagar-hwmon.c
@@ -10,7 +10,6 @@
 
 #include <linux/delay.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/math64.h>
 #include <linux/mfd/lochnagar.h>
 #include <linux/mfd/lochnagar2_regs.h>
@@ -42,9 +41,6 @@ struct lochnagar_hwmon {
 	struct regmap *regmap;
 
 	long power_nsamples[ARRAY_SIZE(lochnagar_chan_names)];
-
-	/* Lock to ensure only a single sensor is read at a time */
-	struct mutex sensor_lock;
 };
 
 enum lochnagar_measure_mode {
@@ -178,26 +174,20 @@ static int read_sensor(struct device *dev, int chan,
 	u32 data;
 	int ret;
 
-	mutex_lock(&priv->sensor_lock);
-
 	ret = do_measurement(regmap, chan, mode, nsamples);
 	if (ret < 0) {
 		dev_err(dev, "Failed to perform measurement: %d\n", ret);
-		goto error;
+		return ret;
 	}
 
 	ret = request_data(regmap, chan, &data);
 	if (ret < 0) {
 		dev_err(dev, "Failed to read measurement: %d\n", ret);
-		goto error;
+		return ret;
 	}
 
 	*val = float_to_long(data, precision);
-
-error:
-	mutex_unlock(&priv->sensor_lock);
-
-	return ret;
+	return 0;
 }
 
 static int read_power(struct device *dev, int chan, long *val)
@@ -378,8 +368,6 @@ static int lochnagar_hwmon_probe(struct platform_device *pdev)
 	if (!priv)
 		return -ENOMEM;
 
-	mutex_init(&priv->sensor_lock);
-
 	priv->regmap = dev_get_regmap(dev->parent, NULL);
 	if (!priv->regmap) {
 		dev_err(dev, "No register map found\n");
-- 
2.45.2

[PATCH 22/29] hwmon: (ltc4282) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/ltc4282.c | 32 ++++----------------------------
 1 file changed, 4 insertions(+), 28 deletions(-)

diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c
index 44102879694a..b9cad89f2cd9 100644
--- a/drivers/hwmon/ltc4282.c
+++ b/drivers/hwmon/ltc4282.c
@@ -17,7 +17,6 @@
 #include <linux/minmax.h>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
-#include <linux/mutex.h>
 #include <linux/regmap.h>
 #include <linux/property.h>
 #include <linux/string.h>
@@ -131,8 +130,6 @@ struct ltc4282_cache {
 
 struct ltc4282_state {
 	struct regmap *map;
-	/* Protect against multiple accesses to the device registers */
-	struct mutex lock;
 	struct clk_hw clk_hw;
 	/*
 	 * Used to cache values for VDD/VSOURCE depending which will be used
@@ -281,14 +278,12 @@ static int __ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
 static int ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
 			      long *val)
 {
-	guard(mutex)(&st->lock);
 	return __ltc4282_read_alarm(st, reg, mask, val);
 }
 
 static int ltc4282_vdd_source_read_in(struct ltc4282_state *st, u32 channel,
 				      long *val)
 {
-	guard(mutex)(&st->lock);
 	if (!st->in0_1_cache[channel].en)
 		return -ENODATA;
 
@@ -300,7 +295,6 @@ static int ltc4282_vdd_source_read_hist(struct ltc4282_state *st, u32 reg,
 {
 	int ret;
 
-	guard(mutex)(&st->lock);
 	if (!st->in0_1_cache[channel].en) {
 		*val = *cached;
 		return 0;
@@ -317,7 +311,6 @@ static int ltc4282_vdd_source_read_hist(struct ltc4282_state *st, u32 reg,
 static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
 				       u32 channel, u32 *cached, long *val)
 {
-	guard(mutex)(&st->lock);
 	if (!st->in0_1_cache[channel].en)
 		return ltc4282_read_voltage_byte_cached(st, reg, st->vfs_out,
 							val, cached);
@@ -328,7 +321,6 @@ static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
 static int ltc4282_vdd_source_read_alm(struct ltc4282_state *st, u32 mask,
 				       u32 channel, long *val)
 {
-	guard(mutex)(&st->lock);
 	if (!st->in0_1_cache[channel].en) {
 		/*
 		 * Do this otherwise alarms can get confused because we clear
@@ -412,9 +404,7 @@ static int ltc4282_read_in(struct ltc4282_state *st, u32 attr, long *val,
 						   channel,
 						   &st->in0_1_cache[channel].in_min_raw, val);
 	case hwmon_in_enable:
-		scoped_guard(mutex, &st->lock) {
-			*val = st->in0_1_cache[channel].en;
-		}
+		*val = st->in0_1_cache[channel].en;
 		return 0;
 	case hwmon_in_fault:
 		/*
@@ -612,15 +602,11 @@ static int ltc4282_read(struct device *dev, enum hwmon_sensor_types type,
 	case hwmon_power:
 		return ltc4282_read_power(st, attr, val);
 	case hwmon_energy:
-		scoped_guard(mutex, &st->lock) {
-			*val = st->energy_en;
-		}
+		*val = st->energy_en;
 		return 0;
 	case hwmon_energy64:
-		scoped_guard(mutex, &st->lock) {
-			if (st->energy_en)
-				return ltc4282_read_energy(st, (s64 *)val);
-		}
+		if (st->energy_en)
+			return ltc4282_read_energy(st, (s64 *)val);
 		return -ENODATA;
 	default:
 		return -EOPNOTSUPP;
@@ -688,7 +674,6 @@ static int __ltc4282_in_write_history(const struct ltc4282_state *st, u32 reg,
 static int ltc4282_in_write_history(struct ltc4282_state *st, u32 reg,
 				    long lowest, long highest, u32 fs)
 {
-	guard(mutex)(&st->lock);
 	return __ltc4282_in_write_history(st, reg, lowest, highest, fs);
 }
 
@@ -696,8 +681,6 @@ static int ltc4282_power_reset_hist(struct ltc4282_state *st)
 {
 	int ret;
 
-	guard(mutex)(&st->lock);
-
 	ret = ltc4282_write_power_word(st, LTC4282_POWER_LOWEST,
 				       st->power_max);
 	if (ret)
@@ -803,7 +786,6 @@ static int ltc4282_vdd_source_write_lim(struct ltc4282_state *st, u32 reg,
 {
 	int ret;
 
-	guard(mutex)(&st->lock);
 	if (st->in0_1_cache[channel].en)
 		ret = ltc4282_write_voltage_byte(st, reg, st->vfs_out, val);
 	else
@@ -821,7 +803,6 @@ static int ltc4282_vdd_source_reset_hist(struct ltc4282_state *st, int channel)
 	if (channel == LTC4282_CHAN_VDD)
 		lowest = st->vdd;
 
-	guard(mutex)(&st->lock);
 	if (st->in0_1_cache[channel].en) {
 		ret = __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
 						 lowest, 0, st->vfs_out);
@@ -861,7 +842,6 @@ static int ltc4282_vdd_source_enable(struct ltc4282_state *st, int channel,
 	int ret, other_chan = ~channel & 0x1;
 	u8 __val = val;
 
-	guard(mutex)(&st->lock);
 	if (st->in0_1_cache[channel].en == !!val)
 		return 0;
 
@@ -938,8 +918,6 @@ static int ltc4282_curr_reset_hist(struct ltc4282_state *st)
 {
 	int ret;
 
-	guard(mutex)(&st->lock);
-
 	ret = __ltc4282_in_write_history(st, LTC4282_VSENSE_LOWEST,
 					 st->vsense_max, 0, 40 * MILLI);
 	if (ret)
@@ -974,7 +952,6 @@ static int ltc4282_energy_enable_set(struct ltc4282_state *st, long val)
 {
 	int ret;
 
-	guard(mutex)(&st->lock);
 	/* setting the bit halts the meter */
 	ret = regmap_update_bits(st->map, LTC4282_ADC_CTRL,
 				 LTC4282_METER_HALT_MASK,
@@ -1699,7 +1676,6 @@ static int ltc4282_probe(struct i2c_client *i2c)
 	if (ret)
 		return ret;
 
-	mutex_init(&st->lock);
 	hwmon = devm_hwmon_device_register_with_info(dev, "ltc4282", st,
 						     &ltc4282_chip_info, NULL);
 	if (IS_ERR(hwmon))
-- 
2.45.2

Re: [PATCH 22/29] hwmon: (ltc4282) Rely on subsystem locking

[Nuno Sá]

On Fri, 2025-10-17 at 06:02 -0700, Guenter Roeck wrote:
> Attribute access is now serialized in the hardware monitoring core,
> so locking in the driver code is no longer necessary. Drop it.
> 
> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
> ---

Reviewed-by: Nuno Sá <nuno.sa@analog.com>

>  drivers/hwmon/ltc4282.c | 32 ++++----------------------------
>  1 file changed, 4 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/hwmon/ltc4282.c b/drivers/hwmon/ltc4282.c
> index 44102879694a..b9cad89f2cd9 100644
> --- a/drivers/hwmon/ltc4282.c
> +++ b/drivers/hwmon/ltc4282.c
> @@ -17,7 +17,6 @@
>  #include <linux/minmax.h>
>  #include <linux/module.h>
>  #include <linux/mod_devicetable.h>
> -#include <linux/mutex.h>
>  #include <linux/regmap.h>
>  #include <linux/property.h>
>  #include <linux/string.h>
> @@ -131,8 +130,6 @@ struct ltc4282_cache {
>  
>  struct ltc4282_state {
>  	struct regmap *map;
> -	/* Protect against multiple accesses to the device registers */
> -	struct mutex lock;
>  	struct clk_hw clk_hw;
>  	/*
>  	 * Used to cache values for VDD/VSOURCE depending which will be used
> @@ -281,14 +278,12 @@ static int __ltc4282_read_alarm(struct ltc4282_state
> *st, u32 reg, u32 mask,
>  static int ltc4282_read_alarm(struct ltc4282_state *st, u32 reg, u32 mask,
>  			      long *val)
>  {
> -	guard(mutex)(&st->lock);
>  	return __ltc4282_read_alarm(st, reg, mask, val);
>  }
>  
>  static int ltc4282_vdd_source_read_in(struct ltc4282_state *st, u32 channel,
>  				      long *val)
>  {
> -	guard(mutex)(&st->lock);
>  	if (!st->in0_1_cache[channel].en)
>  		return -ENODATA;
>  
> @@ -300,7 +295,6 @@ static int ltc4282_vdd_source_read_hist(struct
> ltc4282_state *st, u32 reg,
>  {
>  	int ret;
>  
> -	guard(mutex)(&st->lock);
>  	if (!st->in0_1_cache[channel].en) {
>  		*val = *cached;
>  		return 0;
> @@ -317,7 +311,6 @@ static int ltc4282_vdd_source_read_hist(struct
> ltc4282_state *st, u32 reg,
>  static int ltc4282_vdd_source_read_lim(struct ltc4282_state *st, u32 reg,
>  				       u32 channel, u32 *cached, long *val)
>  {
> -	guard(mutex)(&st->lock);
>  	if (!st->in0_1_cache[channel].en)
>  		return ltc4282_read_voltage_byte_cached(st, reg, st->vfs_out,
>  							val, cached);
> @@ -328,7 +321,6 @@ static int ltc4282_vdd_source_read_lim(struct
> ltc4282_state *st, u32 reg,
>  static int ltc4282_vdd_source_read_alm(struct ltc4282_state *st, u32 mask,
>  				       u32 channel, long *val)
>  {
> -	guard(mutex)(&st->lock);
>  	if (!st->in0_1_cache[channel].en) {
>  		/*
>  		 * Do this otherwise alarms can get confused because we clear
> @@ -412,9 +404,7 @@ static int ltc4282_read_in(struct ltc4282_state *st, u32
> attr, long *val,
>  						   channel,
>  						   &st-
> >in0_1_cache[channel].in_min_raw, val);
>  	case hwmon_in_enable:
> -		scoped_guard(mutex, &st->lock) {
> -			*val = st->in0_1_cache[channel].en;
> -		}
> +		*val = st->in0_1_cache[channel].en;
>  		return 0;
>  	case hwmon_in_fault:
>  		/*
> @@ -612,15 +602,11 @@ static int ltc4282_read(struct device *dev, enum
> hwmon_sensor_types type,
>  	case hwmon_power:
>  		return ltc4282_read_power(st, attr, val);
>  	case hwmon_energy:
> -		scoped_guard(mutex, &st->lock) {
> -			*val = st->energy_en;
> -		}
> +		*val = st->energy_en;
>  		return 0;
>  	case hwmon_energy64:
> -		scoped_guard(mutex, &st->lock) {
> -			if (st->energy_en)
> -				return ltc4282_read_energy(st, (s64 *)val);
> -		}
> +		if (st->energy_en)
> +			return ltc4282_read_energy(st, (s64 *)val);
>  		return -ENODATA;
>  	default:
>  		return -EOPNOTSUPP;
> @@ -688,7 +674,6 @@ static int __ltc4282_in_write_history(const struct
> ltc4282_state *st, u32 reg,
>  static int ltc4282_in_write_history(struct ltc4282_state *st, u32 reg,
>  				    long lowest, long highest, u32 fs)
>  {
> -	guard(mutex)(&st->lock);
>  	return __ltc4282_in_write_history(st, reg, lowest, highest, fs);
>  }
>  
> @@ -696,8 +681,6 @@ static int ltc4282_power_reset_hist(struct ltc4282_state
> *st)
>  {
>  	int ret;
>  
> -	guard(mutex)(&st->lock);
> -
>  	ret = ltc4282_write_power_word(st, LTC4282_POWER_LOWEST,
>  				       st->power_max);
>  	if (ret)
> @@ -803,7 +786,6 @@ static int ltc4282_vdd_source_write_lim(struct
> ltc4282_state *st, u32 reg,
>  {
>  	int ret;
>  
> -	guard(mutex)(&st->lock);
>  	if (st->in0_1_cache[channel].en)
>  		ret = ltc4282_write_voltage_byte(st, reg, st->vfs_out, val);
>  	else
> @@ -821,7 +803,6 @@ static int ltc4282_vdd_source_reset_hist(struct
> ltc4282_state *st, int channel)
>  	if (channel == LTC4282_CHAN_VDD)
>  		lowest = st->vdd;
>  
> -	guard(mutex)(&st->lock);
>  	if (st->in0_1_cache[channel].en) {
>  		ret = __ltc4282_in_write_history(st, LTC4282_VSOURCE_LOWEST,
>  						 lowest, 0, st->vfs_out);
> @@ -861,7 +842,6 @@ static int ltc4282_vdd_source_enable(struct ltc4282_state
> *st, int channel,
>  	int ret, other_chan = ~channel & 0x1;
>  	u8 __val = val;
>  
> -	guard(mutex)(&st->lock);
>  	if (st->in0_1_cache[channel].en == !!val)
>  		return 0;
>  
> @@ -938,8 +918,6 @@ static int ltc4282_curr_reset_hist(struct ltc4282_state
> *st)
>  {
>  	int ret;
>  
> -	guard(mutex)(&st->lock);
> -
>  	ret = __ltc4282_in_write_history(st, LTC4282_VSENSE_LOWEST,
>  					 st->vsense_max, 0, 40 * MILLI);
>  	if (ret)
> @@ -974,7 +952,6 @@ static int ltc4282_energy_enable_set(struct ltc4282_state
> *st, long val)
>  {
>  	int ret;
>  
> -	guard(mutex)(&st->lock);
>  	/* setting the bit halts the meter */
>  	ret = regmap_update_bits(st->map, LTC4282_ADC_CTRL,
>  				 LTC4282_METER_HALT_MASK,
> @@ -1699,7 +1676,6 @@ static int ltc4282_probe(struct i2c_client *i2c)
>  	if (ret)
>  		return ret;
>  
> -	mutex_init(&st->lock);
>  	hwmon = devm_hwmon_device_register_with_info(dev, "ltc4282", st,
>  						     &ltc4282_chip_info,
> NULL);
>  	if (IS_ERR(hwmon))

[PATCH 23/29] hwmon: (aquacomputer_d5next) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/aquacomputer_d5next.c | 37 +++++------------------------
 1 file changed, 6 insertions(+), 31 deletions(-)

diff --git a/drivers/hwmon/aquacomputer_d5next.c b/drivers/hwmon/aquacomputer_d5next.c
index 0dcb8a3a691d..1ca70e726298 100644
--- a/drivers/hwmon/aquacomputer_d5next.c
+++ b/drivers/hwmon/aquacomputer_d5next.c
@@ -20,7 +20,6 @@
 #include <linux/jiffies.h>
 #include <linux/ktime.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/seq_file.h>
 #include <linux/unaligned.h>
 
@@ -551,7 +550,6 @@ struct aqc_data {
 	struct hid_device *hdev;
 	struct device *hwmon_dev;
 	struct dentry *debugfs;
-	struct mutex mutex;	/* Used for locking access when reading and writing PWM values */
 	enum kinds kind;
 	const char *name;
 
@@ -662,7 +660,6 @@ static void aqc_delay_ctrl_report(struct aqc_data *priv)
 	}
 }
 
-/* Expects the mutex to be locked */
 static int aqc_get_ctrl_data(struct aqc_data *priv)
 {
 	int ret;
@@ -680,7 +677,6 @@ static int aqc_get_ctrl_data(struct aqc_data *priv)
 	return ret;
 }
 
-/* Expects the mutex to be locked */
 static int aqc_send_ctrl_data(struct aqc_data *priv)
 {
 	int ret;
@@ -721,11 +717,9 @@ static int aqc_get_ctrl_val(struct aqc_data *priv, int offset, long *val, int ty
 {
 	int ret;
 
-	mutex_lock(&priv->mutex);
-
 	ret = aqc_get_ctrl_data(priv);
 	if (ret < 0)
-		goto unlock_and_return;
+		return ret;
 
 	switch (type) {
 	case AQC_BE16:
@@ -737,9 +731,6 @@ static int aqc_get_ctrl_val(struct aqc_data *priv, int offset, long *val, int ty
 	default:
 		ret = -EINVAL;
 	}
-
-unlock_and_return:
-	mutex_unlock(&priv->mutex);
 	return ret;
 }
 
@@ -747,11 +738,9 @@ static int aqc_set_ctrl_vals(struct aqc_data *priv, int *offsets, long *vals, in
 {
 	int ret, i;
 
-	mutex_lock(&priv->mutex);
-
 	ret = aqc_get_ctrl_data(priv);
 	if (ret < 0)
-		goto unlock_and_return;
+		return ret;
 
 	for (i = 0; i < len; i++) {
 		switch (types[i]) {
@@ -762,18 +751,11 @@ static int aqc_set_ctrl_vals(struct aqc_data *priv, int *offsets, long *vals, in
 			priv->buffer[offsets[i]] = (u8)vals[i];
 			break;
 		default:
-			ret = -EINVAL;
+			return -EINVAL;
 		}
 	}
 
-	if (ret < 0)
-		goto unlock_and_return;
-
-	ret = aqc_send_ctrl_data(priv);
-
-unlock_and_return:
-	mutex_unlock(&priv->mutex);
-	return ret;
+	return aqc_send_ctrl_data(priv);
 }
 
 static int aqc_set_ctrl_val(struct aqc_data *priv, int offset, long val, int type)
@@ -953,13 +935,11 @@ static int aqc_legacy_read(struct aqc_data *priv)
 {
 	int ret, i, sensor_value;
 
-	mutex_lock(&priv->mutex);
-
 	memset(priv->buffer, 0x00, priv->buffer_size);
 	ret = hid_hw_raw_request(priv->hdev, priv->status_report_id, priv->buffer,
 				 priv->buffer_size, HID_FEATURE_REPORT, HID_REQ_GET_REPORT);
 	if (ret < 0)
-		goto unlock_and_return;
+		return ret;
 
 	/* Temperature sensor readings */
 	for (i = 0; i < priv->num_temp_sensors; i++) {
@@ -1020,10 +1000,7 @@ static int aqc_legacy_read(struct aqc_data *priv)
 	}
 
 	priv->updated = jiffies;
-
-unlock_and_return:
-	mutex_unlock(&priv->mutex);
-	return ret;
+	return 0;
 }
 
 static int aqc_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
@@ -1870,8 +1847,6 @@ static int aqc_probe(struct hid_device *hdev, const struct hid_device_id *id)
 		goto fail_and_close;
 	}
 
-	mutex_init(&priv->mutex);
-
 	priv->hwmon_dev = hwmon_device_register_with_info(&hdev->dev, priv->name, priv,
 							  &aqc_chip_info, NULL);
 
-- 
2.45.2

[PATCH 24/29] hwmon: (gpd-fan) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/gpd-fan.c | 56 ++++++++++-------------------------------
 1 file changed, 13 insertions(+), 43 deletions(-)

diff --git a/drivers/hwmon/gpd-fan.c b/drivers/hwmon/gpd-fan.c
index 644dc3ca9df7..57caae9a23eb 100644
--- a/drivers/hwmon/gpd-fan.c
+++ b/drivers/hwmon/gpd-fan.c
@@ -26,9 +26,6 @@
 static char *gpd_fan_board = "";
 module_param(gpd_fan_board, charp, 0444);
 
-// EC read/write locker, protecting a sequence of EC operations
-static DEFINE_MUTEX(gpd_fan_sequence_lock);
-
 enum gpd_board {
 	win_mini,
 	win4_6800u,
@@ -507,87 +504,60 @@ static int gpd_fan_hwmon_read(__always_unused struct device *dev,
 {
 	int ret;
 
-	ret = mutex_lock_interruptible(&gpd_fan_sequence_lock);
-	if (ret)
-		return ret;
-
 	if (type == hwmon_fan) {
 		if (attr == hwmon_fan_input) {
 			ret = gpd_read_rpm();
 
 			if (ret < 0)
-				goto OUT;
+				return ret;
 
 			*val = ret;
-			ret = 0;
-			goto OUT;
+			return 0;
 		}
 	} else if (type == hwmon_pwm) {
 		switch (attr) {
 		case hwmon_pwm_enable:
 			*val = gpd_driver_priv.pwm_enable;
-			ret = 0;
-			goto OUT;
+			return 0;
 		case hwmon_pwm_input:
 			ret = gpd_read_pwm();
 
 			if (ret < 0)
-				goto OUT;
+				return ret;
 
 			*val = ret;
-			ret = 0;
-			goto OUT;
+			return 0;
 		}
 	}
 
-	ret = -EOPNOTSUPP;
-
-OUT:
-	mutex_unlock(&gpd_fan_sequence_lock);
-	return ret;
+	return -EOPNOTSUPP;
 }
 
 static int gpd_fan_hwmon_write(__always_unused struct device *dev,
 			       enum hwmon_sensor_types type, u32 attr,
 			       __always_unused int channel, long val)
 {
-	int ret;
-
-	ret = mutex_lock_interruptible(&gpd_fan_sequence_lock);
-	if (ret)
-		return ret;
-
 	if (type == hwmon_pwm) {
 		switch (attr) {
 		case hwmon_pwm_enable:
-			if (!in_range(val, 0, 3)) {
-				ret = -EINVAL;
-				goto OUT;
-			}
+			if (!in_range(val, 0, 3))
+				return -EINVAL;
 
 			gpd_driver_priv.pwm_enable = val;
 
 			gpd_set_pwm_enable(gpd_driver_priv.pwm_enable);
-			ret = 0;
-			goto OUT;
+			return 0;
 		case hwmon_pwm_input:
-			if (!in_range(val, 0, 256)) {
-				ret = -ERANGE;
-				goto OUT;
-			}
+			if (!in_range(val, 0, 256))
+				return -EINVAL;
 
 			gpd_driver_priv.pwm_value = val;
 
-			ret = gpd_write_pwm(val);
-			goto OUT;
+			return gpd_write_pwm(val);
 		}
 	}
 
-	ret = -EOPNOTSUPP;
-
-OUT:
-	mutex_unlock(&gpd_fan_sequence_lock);
-	return ret;
+	return -EOPNOTSUPP;
 }
 
 static const struct hwmon_ops gpd_fan_ops = {
-- 
2.45.2

[PATCH 25/29] hwmon: (i5500_temp) Drop unnecessary include files

[Guenter Roeck]

The driver does not perform any locking, does not execute or use any sleep
related functionality, and does not allocate memory. Drop the unnecessary
include files.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/i5500_temp.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/hwmon/i5500_temp.c b/drivers/hwmon/i5500_temp.c
index 2a530da21949..bf006cb272b1 100644
--- a/drivers/hwmon/i5500_temp.c
+++ b/drivers/hwmon/i5500_temp.c
@@ -8,13 +8,10 @@
 #include <linux/bitops.h>
 #include <linux/module.h>
 #include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/jiffies.h>
 #include <linux/device.h>
 #include <linux/pci.h>
 #include <linux/hwmon.h>
 #include <linux/err.h>
-#include <linux/mutex.h>
 
 /* Register definitions from datasheet */
 #define REG_TSTHRCATA	0xE2
-- 
2.45.2

[PATCH 26/29] hwmon: (asus_rog_ryujin) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/asus_rog_ryujin.c | 48 +++++++--------------------------
 1 file changed, 9 insertions(+), 39 deletions(-)

diff --git a/drivers/hwmon/asus_rog_ryujin.c b/drivers/hwmon/asus_rog_ryujin.c
index e5e93a20723c..10a1f5aca988 100644
--- a/drivers/hwmon/asus_rog_ryujin.c
+++ b/drivers/hwmon/asus_rog_ryujin.c
@@ -81,10 +81,6 @@ static const char *const rog_ryujin_speed_label[] = {
 struct rog_ryujin_data {
 	struct hid_device *hdev;
 	struct device *hwmon_dev;
-	/* For locking access to buffer */
-	struct mutex buffer_lock;
-	/* For queueing multiple readers */
-	struct mutex status_report_request_mutex;
 	/* For reinitializing the completions below */
 	spinlock_t status_report_request_lock;
 	struct completion cooler_status_received;
@@ -153,18 +149,10 @@ static umode_t rog_ryujin_is_visible(const void *data,
 /* Writes the command to the device with the rest of the report filled with zeroes */
 static int rog_ryujin_write_expanded(struct rog_ryujin_data *priv, const u8 *cmd, int cmd_length)
 {
-	int ret;
-
-	mutex_lock(&priv->buffer_lock);
-
 	memcpy_and_pad(priv->buffer, MAX_REPORT_LENGTH, cmd, cmd_length, 0x00);
-	ret = hid_hw_output_report(priv->hdev, priv->buffer, MAX_REPORT_LENGTH);
-
-	mutex_unlock(&priv->buffer_lock);
-	return ret;
+	return hid_hw_output_report(priv->hdev, priv->buffer, MAX_REPORT_LENGTH);
 }
 
-/* Assumes priv->status_report_request_mutex is locked */
 static int rog_ryujin_execute_cmd(struct rog_ryujin_data *priv, const u8 *cmd, int cmd_length,
 				  struct completion *status_completion)
 {
@@ -196,14 +184,11 @@ static int rog_ryujin_execute_cmd(struct rog_ryujin_data *priv, const u8 *cmd, i
 
 static int rog_ryujin_get_status(struct rog_ryujin_data *priv)
 {
-	int ret = mutex_lock_interruptible(&priv->status_report_request_mutex);
-
-	if (ret < 0)
-		return ret;
+	int ret;
 
 	if (!time_after(jiffies, priv->updated + msecs_to_jiffies(STATUS_VALIDITY))) {
 		/* Data is up to date */
-		goto unlock_and_return;
+		return 0;
 	}
 
 	/* Retrieve cooler status */
@@ -211,36 +196,30 @@ static int rog_ryujin_get_status(struct rog_ryujin_data *priv)
 	    rog_ryujin_execute_cmd(priv, get_cooler_status_cmd, GET_CMD_LENGTH,
 				   &priv->cooler_status_received);
 	if (ret < 0)
-		goto unlock_and_return;
+		return ret;
 
 	/* Retrieve controller status (speeds) */
 	ret =
 	    rog_ryujin_execute_cmd(priv, get_controller_speed_cmd, GET_CMD_LENGTH,
 				   &priv->controller_status_received);
 	if (ret < 0)
-		goto unlock_and_return;
+		return ret;
 
 	/* Retrieve cooler duty */
 	ret =
 	    rog_ryujin_execute_cmd(priv, get_cooler_duty_cmd, GET_CMD_LENGTH,
 				   &priv->cooler_duty_received);
 	if (ret < 0)
-		goto unlock_and_return;
+		return ret;
 
 	/* Retrieve controller duty */
 	ret =
 	    rog_ryujin_execute_cmd(priv, get_controller_duty_cmd, GET_CMD_LENGTH,
 				   &priv->controller_duty_received);
-	if (ret < 0)
-		goto unlock_and_return;
-
-	priv->updated = jiffies;
-
-unlock_and_return:
-	mutex_unlock(&priv->status_report_request_mutex);
 	if (ret < 0)
 		return ret;
 
+	priv->updated = jiffies;
 	return 0;
 }
 
@@ -303,14 +282,11 @@ static int rog_ryujin_write_fixed_duty(struct rog_ryujin_data *priv, int channel
 		 * Retrieve cooler duty since both pump and internal fan are set
 		 * together, then write back with one of them modified.
 		 */
-		ret = mutex_lock_interruptible(&priv->status_report_request_mutex);
-		if (ret < 0)
-			return ret;
 		ret =
 		    rog_ryujin_execute_cmd(priv, get_cooler_duty_cmd, GET_CMD_LENGTH,
 					   &priv->cooler_duty_received);
 		if (ret < 0)
-			goto unlock_and_return;
+			return ret;
 
 		memcpy(set_cmd, set_cooler_duty_cmd, SET_CMD_LENGTH);
 
@@ -329,11 +305,7 @@ static int rog_ryujin_write_fixed_duty(struct rog_ryujin_data *priv, int channel
 			set_cmd[RYUJIN_SET_COOLER_FAN_DUTY_OFFSET] = val;
 		}
 
-		ret = rog_ryujin_execute_cmd(priv, set_cmd, SET_CMD_LENGTH, &priv->cooler_duty_set);
-unlock_and_return:
-		mutex_unlock(&priv->status_report_request_mutex);
-		if (ret < 0)
-			return ret;
+		return rog_ryujin_execute_cmd(priv, set_cmd, SET_CMD_LENGTH, &priv->cooler_duty_set);
 	} else {
 		/*
 		 * Controller fan duty (channel == 2). No need to retrieve current
@@ -538,8 +510,6 @@ static int rog_ryujin_probe(struct hid_device *hdev, const struct hid_device_id
 		goto fail_and_close;
 	}
 
-	mutex_init(&priv->status_report_request_mutex);
-	mutex_init(&priv->buffer_lock);
 	spin_lock_init(&priv->status_report_request_lock);
 	init_completion(&priv->cooler_status_received);
 	init_completion(&priv->controller_status_received);
-- 
2.45.2

[PATCH 27/29] hwmon: (chipcap2) Drop unnecessary include files

[Guenter Roeck]

The driver does not perform any locking, does not execute or use any sleep
related functionality, and does not allocate memory. Drop the unnecessary
include files.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/chipcap2.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/hwmon/chipcap2.c b/drivers/hwmon/chipcap2.c
index 9d071f7ca9d2..645b8c2e704e 100644
--- a/drivers/hwmon/chipcap2.c
+++ b/drivers/hwmon/chipcap2.c
@@ -81,7 +81,6 @@ struct cc2_data {
 	struct completion complete;
 	struct device *hwmon;
 	struct i2c_client *client;
-	struct mutex dev_access_lock; /* device access lock */
 	struct regulator *regulator;
 	const char *name;
 	int irq_ready;
@@ -558,8 +557,6 @@ static int cc2_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 {
 	struct cc2_data *data = dev_get_drvdata(dev);
 
-	guard(mutex)(&data->dev_access_lock);
-
 	switch (type) {
 	case hwmon_temp:
 		return cc2_measurement(data, type, val);
@@ -600,8 +597,6 @@ static int cc2_write(struct device *dev, enum hwmon_sensor_types type, u32 attr,
 	if (val < 0 || val > CC2_RH_MAX)
 		return -EINVAL;
 
-	guard(mutex)(&data->dev_access_lock);
-
 	switch (attr) {
 	case hwmon_humidity_min:
 		cmd = CC2_W_ALARM_L_ON;
@@ -708,8 +703,6 @@ static int cc2_probe(struct i2c_client *client)
 
 	i2c_set_clientdata(client, data);
 
-	mutex_init(&data->dev_access_lock);
-
 	data->client = client;
 
 	data->regulator = devm_regulator_get_exclusive(dev, "vdd");
-- 
2.45.2

[PATCH 28/29] hwmon: (corsair-psu) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/corsair-psu.c | 13 ++-----------
 1 file changed, 2 insertions(+), 11 deletions(-)

diff --git a/drivers/hwmon/corsair-psu.c b/drivers/hwmon/corsair-psu.c
index 6b5c8f200780..dddbd2463f8d 100644
--- a/drivers/hwmon/corsair-psu.c
+++ b/drivers/hwmon/corsair-psu.c
@@ -9,11 +9,9 @@
 #include <linux/errno.h>
 #include <linux/hid.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/jiffies.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
-#include <linux/mutex.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 
@@ -124,7 +122,6 @@ struct corsairpsu_data {
 	struct device *hwmon_dev;
 	struct dentry *debugfs;
 	struct completion wait_completion;
-	struct mutex lock; /* for locking access to cmd_buffer */
 	u8 *cmd_buffer;
 	char vendor[REPLY_SIZE];
 	char product[REPLY_SIZE];
@@ -220,7 +217,6 @@ static int corsairpsu_request(struct corsairpsu_data *priv, u8 cmd, u8 rail, voi
 {
 	int ret;
 
-	mutex_lock(&priv->lock);
 	switch (cmd) {
 	case PSU_CMD_RAIL_VOLTS_HCRIT:
 	case PSU_CMD_RAIL_VOLTS_LCRIT:
@@ -230,17 +226,13 @@ static int corsairpsu_request(struct corsairpsu_data *priv, u8 cmd, u8 rail, voi
 	case PSU_CMD_RAIL_WATTS:
 		ret = corsairpsu_usb_cmd(priv, 2, PSU_CMD_SELECT_RAIL, rail, NULL);
 		if (ret < 0)
-			goto cmd_fail;
+			return ret;
 		break;
 	default:
 		break;
 	}
 
-	ret = corsairpsu_usb_cmd(priv, 3, cmd, 0, data);
-
-cmd_fail:
-	mutex_unlock(&priv->lock);
-	return ret;
+	return corsairpsu_usb_cmd(priv, 3, cmd, 0, data);
 }
 
 static int corsairpsu_get_value(struct corsairpsu_data *priv, u8 cmd, u8 rail, long *val)
@@ -797,7 +789,6 @@ static int corsairpsu_probe(struct hid_device *hdev, const struct hid_device_id
 
 	priv->hdev = hdev;
 	hid_set_drvdata(hdev, priv);
-	mutex_init(&priv->lock);
 	init_completion(&priv->wait_completion);
 
 	hid_device_io_start(hdev);
-- 
2.45.2

[PATCH 29/29] hwmon: (corsair-psu) Rely on subsystem locking

[Guenter Roeck]

Attribute access is now serialized in the hardware monitoring core,
so locking in the driver code is no longer necessary. Drop it.

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
---
 drivers/hwmon/npcm750-pwm-fan.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/drivers/hwmon/npcm750-pwm-fan.c b/drivers/hwmon/npcm750-pwm-fan.c
index 802c73def428..c8f5e695fb6d 100644
--- a/drivers/hwmon/npcm750-pwm-fan.c
+++ b/drivers/hwmon/npcm750-pwm-fan.c
@@ -4,7 +4,6 @@
 #include <linux/clk.h>
 #include <linux/device.h>
 #include <linux/hwmon.h>
-#include <linux/hwmon-sysfs.h>
 #include <linux/interrupt.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -198,7 +197,6 @@ struct npcm7xx_pwm_fan_data {
 	int pwm_modules;
 	struct clk *pwm_clk;
 	struct clk *fan_clk;
-	struct mutex pwm_lock[NPCM7XX_PWM_MAX_MODULES];
 	spinlock_t fan_lock[NPCM7XX_FAN_MAX_MODULE];
 	int fan_irq[NPCM7XX_FAN_MAX_MODULE];
 	bool pwm_present[NPCM7XX_PWM_MAX_CHN_NUM];
@@ -221,7 +219,6 @@ static int npcm7xx_pwm_config_set(struct npcm7xx_pwm_fan_data *data,
 	/*
 	 * Config PWM Comparator register for setting duty cycle
 	 */
-	mutex_lock(&data->pwm_lock[module]);
 
 	/* write new CMR value  */
 	iowrite32(val, NPCM7XX_PWM_REG_CMRx(data->pwm_base, module, pwm_ch));
@@ -245,7 +242,6 @@ static int npcm7xx_pwm_config_set(struct npcm7xx_pwm_fan_data *data,
 		env_bit = NPCM7XX_PWM_CTRL_CH3_INV_BIT;
 		break;
 	default:
-		mutex_unlock(&data->pwm_lock[module]);
 		return -ENODEV;
 	}
 
@@ -260,8 +256,6 @@ static int npcm7xx_pwm_config_set(struct npcm7xx_pwm_fan_data *data,
 	}
 
 	iowrite32(tmp_buf, NPCM7XX_PWM_REG_CR(data->pwm_base, module));
-	mutex_unlock(&data->pwm_lock[module]);
-
 	return 0;
 }
 
@@ -932,8 +926,8 @@ static int npcm7xx_pwm_fan_probe(struct platform_device *pdev)
 	struct resource *res;
 	struct device *hwmon;
 	char name[20];
-	int ret, cnt;
 	u32 output_freq;
+	int ret;
 	u32 i;
 
 	np = dev->of_node;
@@ -985,9 +979,6 @@ static int npcm7xx_pwm_fan_probe(struct platform_device *pdev)
 	output_freq = npcm7xx_pwm_init(data);
 	npcm7xx_fan_init(data);
 
-	for (cnt = 0; cnt < data->pwm_modules; cnt++)
-		mutex_init(&data->pwm_lock[cnt]);
-
 	for (i = 0; i < NPCM7XX_FAN_MAX_MODULE; i++) {
 		spin_lock_init(&data->fan_lock[i]);
 
-- 
2.45.2