linux-kernel - [PATCH v2] regulator: core: fix error path for regulator_set_voltage

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Message-ID: <20190318163132.1BB633FBA2@swsrvapps-01.diasemi.com>
Date:   Mon, 18 Mar 2019 16:17:57 +0000
From:   Steve Twiss <stwiss.opensource@...semi.com>
To:     Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>
CC:     LKML <linux-kernel@...r.kernel.org>,
        Maciej Purski <m.purski@...subg.com>,
        Dmitry Osipenko <digetx@...il.com>,
        Support Opensource <support.opensource@...semi.com>
Subject: [PATCH v2] regulator: core: fix error path for
 regulator_set_voltage_unlocked

During several error paths in the function
regulator_set_voltage_unlocked() the value of 'ret' can take on negative
error values. However, in calls that go through the 'goto out' statement,
this return value is lost and return 0 is used instead, indicating a
'pass'.

There are several cases where this function should legitimately return a
fail instead of a pass: one such case includes constraints check during
voltage selection in the call to regulator_check_voltage(), which can
have -EINVAL for the case when an unsupported voltage is incorrectly
requested. In that case, -22 is expected as the return value, not 0.

Fixes: 9243a195be7a ("regulator: core: Change voltage setting path")
Cc: stable <stable@...r.kernel.org>
Signed-off-by: Steve Twiss <stwiss.opensource@...semi.com>
---
 drivers/regulator/core.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index 68473d0..968dcd9 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -3322,15 +3322,12 @@ static int regulator_set_voltage_unlocked(struct regulator *regulator,

 	/* for not coupled regulators this will just set the voltage */
 	ret = regulator_balance_voltage(rdev, state);
-	if (ret < 0)
-		goto out2;
+	if (ret < 0) {
+		voltage->min_uV = old_min_uV;
+		voltage->max_uV = old_max_uV;
+	}

 out:
-	return 0;
-out2:
-	voltage->min_uV = old_min_uV;
-	voltage->max_uV = old_max_uV;
-
 	return ret;
 }

-- 
1.9.3