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| author | Rui Zhang <zr.zhang@vivo.com> | 2022-12-01 06:38:06 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-01-14 12:16:19 +0300 |
| commit | 4b737246ff50f810d6ab4be13c1388a07f0c14b1 (patch) | |
| tree | f6f4ccdd687ed00b19e7382539f6f6e94159199a /drivers/regulator | |
| parent | 17c2eb9ce8c16439b1ead765f565a38238cd94e0 (diff) | |
| download | linux-4b737246ff50f810d6ab4be13c1388a07f0c14b1.tar.xz | |
regulator: core: fix use_count leakage when handling boot-on
[ 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>
Diffstat (limited to 'drivers/regulator')
| -rw-r--r-- | drivers/regulator/core.c | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 4472c31b9b00..df746ba5c1bc 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -1428,7 +1428,13 @@ 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); |