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Commit bf78aca8 authored by Patrick Rudolph's avatar Patrick Rudolph Committed by Greg Kroah-Hartman
Browse files

hwmon: (pmbus) Add mutex to regulator ops 



[ Upstream commit 686d303ee6301261b422ea51e64833d7909a2c36 ]

On PMBUS devices with multiple pages, the regulator ops need to be
protected with the update mutex. This prevents accidentally changing
the page in a separate thread while operating on the PMBUS_OPERATION
register.

Tested on Infineon xdpe11280 while a separate thread polls for sensor
data.

Signed-off-by: default avatarPatrick Rudolph <patrick.rudolph@9elements.com>
Signed-off-by: default avatarMarcello Sylvester Bauer <sylv@sylv.io>
Link: https://lore.kernel.org/r/b991506bcbf665f7af185945f70bf9d5cf04637c.1645804976.git.sylv@sylv.io


Fixes: ddbb4db4 ("hwmon: (pmbus) Add regulator support")
Cc: Alan Tull <atull@opensource.altera.com>
Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 00d67f54

drivers/hwmon/pmbus/pmbus_core.c

+13 −3
Original line number Diff line number Diff line
@@ -2174,10 +2174,14 @@ static int pmbus_regulator_is_enabled(struct regulator_dev *rdev) 
{

	struct device *dev = rdev_get_dev(rdev);

	struct i2c_client *client = to_i2c_client(dev->parent);

	struct pmbus_data *data = i2c_get_clientdata(client);

	u8 page = rdev_get_id(rdev);

	int ret;



	mutex_lock(&data->update_lock);

	ret = pmbus_read_byte_data(client, page, PMBUS_OPERATION);

	mutex_unlock(&data->update_lock);



	if (ret < 0)

		return ret;
@@ -2188,11 +2192,17 @@ static int _pmbus_regulator_on_off(struct regulator_dev *rdev, bool enable) 
{

	struct device *dev = rdev_get_dev(rdev);

	struct i2c_client *client = to_i2c_client(dev->parent);

	struct pmbus_data *data = i2c_get_clientdata(client);

	u8 page = rdev_get_id(rdev);

	int ret;



	return pmbus_update_byte_data(client, page, PMBUS_OPERATION,

	mutex_lock(&data->update_lock);

	ret = pmbus_update_byte_data(client, page, PMBUS_OPERATION,

				     PB_OPERATION_CONTROL_ON,

				     enable ? PB_OPERATION_CONTROL_ON : 0);

	mutex_unlock(&data->update_lock);



	return ret;

}



static int pmbus_regulator_enable(struct regulator_dev *rdev)