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regulator: core: fix false positive in regulator_late_cleanup()
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[ Upstream commit 4e2a354 ]

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>
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Oliver Barta authored and gregkh committed Mar 8, 2022
1 parent 467d664 commit 6e7015d
Showing 1 changed file with 3 additions and 10 deletions.
13 changes: 3 additions & 10 deletions drivers/regulator/core.c
Expand Up @@ -5862,9 +5862,8 @@ 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;
Expand All @@ -5877,14 +5876,8 @@ 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()) {
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