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Message-Id: <20220607164943.387945727@linuxfoundation.org>
Date: Tue, 7 Jun 2022 18:59:12 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
stable@...r.kernel.org, Zev Weiss <zev@...ilderbeest.net>,
Mark Brown <broonie@...nel.org>,
Sasha Levin <sashal@...nel.org>
Subject: [PATCH 5.15 287/667] regulator: core: Fix enable_count imbalance with EXCLUSIVE_GET
From: Zev Weiss <zev@...ilderbeest.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@...ilderbeest.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@...nel.org>
Signed-off-by: Sasha Levin <sashal@...nel.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 46e76b5b21ef..f4f28e5888b1 100644
--- a/drivers/regulator/core.c
+++ b/drivers/regulator/core.c
@@ -2132,10 +2132,13 @@ 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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