regulator: core: fix false positive in regulator_late_cleanup()
authorOliver Barta <oliver.barta@aptiv.com>
Tue, 8 Feb 2022 08:46:45 +0000 (09:46 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Tue, 8 Mar 2022 18:12:29 +0000 (19:12 +0100)
[ Upstream commit 4e2a354e3775870ca823f1fb29bbbffbe11059a6 ]

The check done by regulator_late_cleanup() to detect whether a regulator
is on was inconsistent with the check done by _regulator_is_enabled().
While _regulator_is_enabled() takes the enable GPIO into account,
regulator_late_cleanup() was not doing that.

This resulted in a false positive, e.g. when a GPIO-controlled fixed
regulator was used, which was not enabled at boot time, e.g.

reg_disp_1v2: reg_disp_1v2 {
compatible = "regulator-fixed";
regulator-name = "display_1v2";
regulator-min-microvolt = <1200000>;
regulator-max-microvolt = <1200000>;
gpio = <&tlmm 148 0>;
enable-active-high;
};

Such regulator doesn't have an is_enabled() operation. Nevertheless
it's state can be determined based on the enable GPIO. The check in
regulator_late_cleanup() wrongly assumed that the regulator is on and
tried to disable it.

Signed-off-by: Oliver Barta <oliver.barta@aptiv.com>
Link: https://lore.kernel.org/r/20220208084645.8686-1-oliver.barta@aptiv.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
drivers/regulator/core.c

index ca6caba..46e76b5 100644 (file)
@@ -6010,9 +6010,8 @@ core_initcall(regulator_init);
 static int regulator_late_cleanup(struct device *dev, void *data)
 {
        struct regulator_dev *rdev = dev_to_rdev(dev);
-       const struct regulator_ops *ops = rdev->desc->ops;
        struct regulation_constraints *c = rdev->constraints;
-       int enabled, ret;
+       int ret;
 
        if (c && c->always_on)
                return 0;
@@ -6025,14 +6024,8 @@ static int regulator_late_cleanup(struct device *dev, void *data)
        if (rdev->use_count)
                goto unlock;
 
-       /* If we can't read the status assume it's always on. */
-       if (ops->is_enabled)
-               enabled = ops->is_enabled(rdev);
-       else
-               enabled = 1;
-
-       /* But if reading the status failed, assume that it's off. */
-       if (enabled <= 0)
+       /* If reading the status failed, assume that it's off. */
+       if (_regulator_is_enabled(rdev) <= 0)
                goto unlock;
 
        if (have_full_constraints()) {