Commit cd4cfd99 authored May 04, 2022 by Zev Weiss Committed by Greg Kroah-Hartman Jun 14, 2022

regulator: core: Fix enable_count imbalance with EXCLUSIVE_GET



[ 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: 5451781d ("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>

parent db5a21f2

drivers/regulator/core.c

+5 −2

Original line number	Diff line number	Diff line
		@@ -1988,10 +1988,13 @@ 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;
		}
		}

		device_link_add(dev, &rdev->dev, DL_FLAG_STATELESS);