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    Subject[PATCH 5.18 392/879] regulator: core: Fix enable_count imbalance with EXCLUSIVE_GET
    Date
    From: Zev Weiss <zev@bewilderbeest.net>

    [ Upstream commit c3e3ca05dae37f8f74bb80358efd540911cbc2c8 ]

    Since the introduction of regulator->enable_count, a driver that did
    an exclusive get on an already-enabled regulator would end up with
    enable_count initialized to 0 but rdev->use_count initialized to 1.
    With that starting point the regulator is effectively stuck enabled,
    because if the driver attempted to disable it it would fail the
    enable_count underflow check in _regulator_handle_consumer_disable().

    The EXCLUSIVE_GET path in _regulator_get() now initializes
    enable_count along with rdev->use_count so that the regulator can be
    disabled without underflowing the former.

    Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
    Fixes: 5451781dadf85 ("regulator: core: Only count load for enabled consumers")
    Link: https://lore.kernel.org/r/20220505043152.12933-1-zev@bewilderbeest.net
    Signed-off-by: Mark Brown <broonie@kernel.org>
    Signed-off-by: Sasha Levin <sashal@kernel.org>
    ---
    drivers/regulator/core.c | 7 +++++--
    1 file changed, 5 insertions(+), 2 deletions(-)

    diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c
    index d2553970a67b..c4d844ffad7a 100644
    --- a/drivers/regulator/core.c
    +++ b/drivers/regulator/core.c
    @@ -2133,10 +2133,13 @@ struct regulator *_regulator_get(struct device *dev, const char *id,
    rdev->exclusive = 1;

    ret = _regulator_is_enabled(rdev);
    - if (ret > 0)
    + if (ret > 0) {
    rdev->use_count = 1;
    - else
    + regulator->enable_count = 1;
    + } else {
    rdev->use_count = 0;
    + regulator->enable_count = 0;
    + }
    }

    link = device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);
    --
    2.35.1


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