From: Rui Zhang zr.zhang@vivo.com
[ 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@vivo.com Link: https://lore.kernel.org/r/20221201033806.2567812-1-zr.zhang@vivo.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 c0f368f1b49f..02ea917c7fd1 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1578,7 +1578,13 @@ 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);