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| author | Rui Zhang <zr.zhang@vivo.com> | 2023-11-03 08:42:31 +0100 |
|---|---|---|
| committer | Mark Brown <broonie@kernel.org> | 2023-11-13 02:26:30 +0100 |
| commit | 7993d3a9c34f609c02171e115fd12c10e2105ff4 (patch) | |
| tree | f76508674be9f509ddf1d90d85997a1f7fbb2264 /drivers/regulator | |
| parent | regulator: core: Add option to prevent disabling unused regulators (diff) | |
| download | linux-7993d3a9c34f609c02171e115fd12c10e2105ff4.tar.xz linux-7993d3a9c34f609c02171e115fd12c10e2105ff4.zip | |
regulator: core: Only increment use_count when enable_count changes
The use_count of a regulator should only be incremented when the
enable_count changes from 0 to 1. Similarly, the use_count should
only be decremented when the enable_count changes from 1 to 0.
In the previous implementation, use_count was sometimes decremented
to 0 when some consumer called unbalanced disable,
leading to unexpected disable even the regulator is enabled by
other consumers. With this change, the use_count accurately reflects
the number of users which the regulator is enabled.
This should make things more robust in the case where a consumer does
leak references.
Signed-off-by: Rui Zhang <zr.zhang@vivo.com>
Link: https://lore.kernel.org/r/20231103074231.8031-1-zr.zhang@vivo.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Diffstat (limited to 'drivers/regulator')
| -rw-r--r-- | drivers/regulator/core.c | 56 |
1 files changed, 30 insertions, 26 deletions
diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 79777495cc3a..00221ff369c2 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -2918,7 +2918,8 @@ static int _regulator_enable(struct regulator *regulator) /* Fallthrough on positive return values - already enabled */ } - rdev->use_count++; + if (regulator->enable_count == 1) + rdev->use_count++; return 0; @@ -2993,37 +2994,40 @@ static int _regulator_disable(struct regulator *regulator) lockdep_assert_held_once(&rdev->mutex.base); - if (WARN(rdev->use_count <= 0, + if (WARN(regulator->enable_count == 0, "unbalanced disables for %s\n", rdev_get_name(rdev))) return -EIO; - /* are we the last user and permitted to disable ? */ - if (rdev->use_count == 1 && - (rdev->constraints && !rdev->constraints->always_on)) { - - /* we are last user */ - if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) { - ret = _notifier_call_chain(rdev, - REGULATOR_EVENT_PRE_DISABLE, - NULL); - if (ret & NOTIFY_STOP_MASK) - return -EINVAL; - - ret = _regulator_do_disable(rdev); - if (ret < 0) { - rdev_err(rdev, "failed to disable: %pe\n", ERR_PTR(ret)); - _notifier_call_chain(rdev, - REGULATOR_EVENT_ABORT_DISABLE, + if (regulator->enable_count == 1) { + /* disabling last enable_count from this regulator */ + /* are we the last user and permitted to disable ? */ + if (rdev->use_count == 1 && + (rdev->constraints && !rdev->constraints->always_on)) { + + /* we are last user */ + if (regulator_ops_is_valid(rdev, REGULATOR_CHANGE_STATUS)) { + ret = _notifier_call_chain(rdev, + REGULATOR_EVENT_PRE_DISABLE, + NULL); + if (ret & NOTIFY_STOP_MASK) + return -EINVAL; + + ret = _regulator_do_disable(rdev); + if (ret < 0) { + rdev_err(rdev, "failed to disable: %pe\n", ERR_PTR(ret)); + _notifier_call_chain(rdev, + REGULATOR_EVENT_ABORT_DISABLE, + NULL); + return ret; + } + _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, NULL); - return ret; } - _notifier_call_chain(rdev, REGULATOR_EVENT_DISABLE, - NULL); - } - rdev->use_count = 0; - } else if (rdev->use_count > 1) { - rdev->use_count--; + rdev->use_count = 0; + } else if (rdev->use_count > 1) { + rdev->use_count--; + } } if (ret == 0) |