Messages in this thread Patch in this message | | | From | Rui Zhang <> | Subject | [PATCH v2 RESEND] regulator: core: fix use_count leakage when handling boot-on | Date | Thu, 1 Dec 2022 11:38:06 +0800 |
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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> --- 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); base-commit: 01f856ae6d0ca5ad0505b79bf2d22d7ca439b2a1 -- 2.34.1
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