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hwmon: (da9052) Synchronize access with mfd

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[ Upstream commit 333e22db22 ]

When tsi-as-adc is configured it is possible for in7[0123]_input read to
return an incorrect value if a concurrent read to in[456]_input is
performed. This is caused by a concurrent manipulation of the mux
channel without proper locking as hwmon and mfd use different locks for
synchronization.

Switch hwmon to use the same lock as mfd when accessing the TSI channel.

Fixes: 4f16cab19a ("hwmon: da9052: Add support for TSI channel")
Signed-off-by: Samu Nuutamo <samu.nuutamo@vincit.fi>
[rebase to current master, reword commit message slightly]
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Samu Nuutamo 2020-05-11 13:02:19 +02:00 committed by Greg Kroah-Hartman
parent 6e7253dc45
commit e1608af170
1 changed files with 2 additions and 2 deletions
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4
drivers/hwmon/da9052-hwmon.c
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@ -244,9 +244,9 @@ static ssize_t da9052_tsi_show(struct device *dev,
int channel = to_sensor_dev_attr(devattr)->index;
int ret;
mutex_lock(&hwmon->hwmon_lock);
mutex_lock(&hwmon->da9052->auxadc_lock);
ret = __da9052_read_tsi(dev, channel);
mutex_unlock(&hwmon->hwmon_lock);
mutex_unlock(&hwmon->da9052->auxadc_lock);
if (ret < 0)
return ret;