[PATCH AUTOSEL 5.15 06/28] regulator: core: fix false positive in regulator_late_cleanup()

Sasha Levin
2022-02-23T02:31:06Z

From: Oliver Barta <oliver.barta@aptiv.com>

[ 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 | 13 +++----------
1 file changed, 3 insertions(+), 10 deletions(-)

diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
index ca6caba8a191a..46e76b5b21efe 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -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()) {
--
2.34.1