From: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx> [ 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: Patrick Rudolph <patrick.rudolph@xxxxxxxxxxxxx> Signed-off-by: Marcello Sylvester Bauer <sylv@xxxxxxx> Link: https://lore.kernel.org/r/b991506bcbf665f7af185945f70bf9d5cf04637c.1645804976.git.sylv@xxxxxxx Fixes: ddbb4db4ced1b ("hwmon: (pmbus) Add regulator support") Cc: Alan Tull <atull@xxxxxxxxxxxxxxxxxxxxx> Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/hwmon/pmbus/pmbus_core.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index cb9064ac4977..66c72aedde5e 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -1861,10 +1861,14 @@ 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; @@ -1875,11 +1879,17 @@ 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, - PB_OPERATION_CONTROL_ON, - enable ? PB_OPERATION_CONTROL_ON : 0); + 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) -- 2.34.1
