drivers/regulator: fix a missing check of return value

[ Upstream commit 966e927bf8cc6a44f8b72582a1d6d3ffc73b12ad ]

If palmas_smps_read() fails, we should not use the read data in "reg"
which may contain random value. The fix inserts a check for the return
value of palmas_smps_read(): If it fails, we return the error code
upstream and stop using "reg".

Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/regulator/palmas-regulator.c b/drivers/regulator/palmas-regulator.c
index bb5ab7d78895b817a9d42e03e6bd890d6b99e33e..c2cc392a27d4075ffc40dc123a78775d0e034a8f 100644 (file)
--- a/drivers/regulator/palmas-regulator.c
+++ b/drivers/regulator/palmas-regulator.c
@@ -443,13 +443,16 @@ static int palmas_ldo_write(struct palmas *palmas, unsigned int reg,
 static int palmas_set_mode_smps(struct regulator_dev *dev, unsigned int mode)
 {
        int id = rdev_get_id(dev);
+       int ret;
        struct palmas_pmic *pmic = rdev_get_drvdata(dev);
        struct palmas_pmic_driver_data *ddata = pmic->palmas->pmic_ddata;
        struct palmas_regs_info *rinfo = &ddata->palmas_regs_info[id];
        unsigned int reg;
        bool rail_enable = true;
 
-       palmas_smps_read(pmic->palmas, rinfo->ctrl_addr, &reg);
+       ret = palmas_smps_read(pmic->palmas, rinfo->ctrl_addr, &reg);
+       if (ret)
+               return ret;
 
        reg &= ~PALMAS_SMPS12_CTRL_MODE_ACTIVE_MASK;