From: Patrick Rudolph patrick.rudolph@9elements.com
stable inclusion from stable-v5.10.110 commit ec8536f7012edd8ee96a35d57d748564fcc3656f bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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[ 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@9elements.com Signed-off-by: Marcello Sylvester Bauer sylv@sylv.io Link: https://lore.kernel.org/r/b991506bcbf665f7af185945f70bf9d5cf04637c.164580497... Fixes: ddbb4db4ced1b ("hwmon: (pmbus) Add regulator support") Cc: Alan Tull atull@opensource.altera.com Signed-off-by: Guenter Roeck linux@roeck-us.net Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yu Liao liaoyu15@huawei.com Reviewed-by: Wei Li liwei391@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- 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 71798fde2ef0..7a13057007d9 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -2255,10 +2255,14 @@ 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;
@@ -2269,11 +2273,17 @@ 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)