From: Rui Zhang <zr.zhang@xxxxxxxx> [ Upstream commit 0591b14ce0398125439c759f889647369aa616a0 ] I found a use_count leakage towards supply regulator of rdev with boot-on option. ┌───────────────────┐ ┌───────────────────┐ │ regulator_dev A │ │ regulator_dev B │ │ (boot-on) │ │ (boot-on) │ │ use_count=0 │◀──supply──│ use_count=1 │ │ │ │ │ └───────────────────┘ └───────────────────┘ In case of rdev(A) configured with `regulator-boot-on', the use_count of supplying regulator(B) will increment inside regulator_enable(rdev->supply). Thus, B will acts like always-on, and further balanced regulator_enable/disable cannot actually disable it anymore. However, B was also configured with `regulator-boot-on', we wish it could be disabled afterwards. Signed-off-by: Rui Zhang <zr.zhang@xxxxxxxx> Link: https://lore.kernel.org/r/20221201033806.2567812-1-zr.zhang@xxxxxxxx Signed-off-by: Mark Brown <broonie@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/regulator/core.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index e8c00a884f1f..1cfac32121c0 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1596,7 +1596,13 @@ static int set_machine_constraints(struct regulator_dev *rdev) if (rdev->supply_name && !rdev->supply) return -EPROBE_DEFER; - if (rdev->supply) { + /* If supplying regulator has already been enabled, + * it's not intended to have use_count increment + * when rdev is only boot-on. + */ + if (rdev->supply && + (rdev->constraints->always_on || + !regulator_is_enabled(rdev->supply))) { ret = regulator_enable(rdev->supply); if (ret < 0) { _regulator_put(rdev->supply); -- 2.35.1
