regulator: core: Fix error return for /sys access

regulator_uV_show() is missing error handling if regulator_get_voltage_rdev()
returns negative values. Instead it prints the errno as a string, e.g. -EINVAL
as "-22" which could be interpreted as -22 µV.

We also do not need to hold the lock while converting the integer to a string.

Reported-by: Adam Ford <aford173@gmail.com>
Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
Tested-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/f37f2a1276efcb34cf3b7f1a25481175be048806.1568143348.git.hns@goldelico.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 340db986b67fffc8d6ab00a866971a51ea0a4d6b..afe94470b67f7588a28930731d3a4ab6f4d2a331 100644 (file)
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -568,13 +568,15 @@ static ssize_t regulator_uV_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
 {
        struct regulator_dev *rdev = dev_get_drvdata(dev);
-       ssize_t ret;
+       int uV;
 
        regulator_lock(rdev);
-       ret = sprintf(buf, "%d\n", regulator_get_voltage_rdev(rdev));
+       uV = regulator_get_voltage_rdev(rdev);
        regulator_unlock(rdev);
 
-       return ret;
+       if (uV < 0)
+               return uV;
+       return sprintf(buf, "%d\n", uV);
 }
 static DEVICE_ATTR(microvolts, 0444, regulator_uV_show, NULL);