Commit a2151374 authored Mar 30, 2016 by Jon Hunter Committed by Mark Brown Mar 30, 2016

regulator: Fix deadlock during regulator registration



Commit 5e3ca2b3 ("regulator: Try to resolve regulators supplies on
registration") added a call to regulator_resolve_supply() within
regulator_register() where the regulator_list_mutex is held. This causes
a deadlock to occur on the Tegra114 Dalmore board when the palmas PMIC
is registered because regulator_register_resolve_supply() calls
regulator_dev_lookup() which may try to acquire the regulator_list_mutex
again.

Fix this by releasing the mutex before calling
regulator_register_resolve_supply() and update the error exit path to
ensure the mutex is released on an error.

[Made commit message more legible -- broonie]

Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

parent 5e3ca2b3

drivers/regulator/core.c

+5 −5

Original line number	Diff line number	Diff line
		@@ -3991,12 +3991,11 @@ regulator_register(const struct regulator_desc *regulator_desc,
		}

		rdev_init_debugfs(rdev);
		mutex_unlock(&regulator_list_mutex);

		/* try to resolve regulators supply since a new one was registered */
		class_for_each_device(&regulator_class, NULL, NULL,
		regulator_register_resolve_supply);
		out:
		mutex_unlock(&regulator_list_mutex);
		kfree(config);
		return rdev;

		@@ -4007,15 +4006,16 @@ regulator_register(const struct regulator_desc *regulator_desc,
		regulator_ena_gpio_free(rdev);
		device_unregister(&rdev->dev);
		/* device core frees rdev */
		rdev = ERR_PTR(ret);
		goto out;

		wash:
		regulator_ena_gpio_free(rdev);
		clean:
		kfree(rdev);
		rdev = ERR_PTR(ret);
		goto out;
		out:
		mutex_unlock(&regulator_list_mutex);
		kfree(config);
		return ERR_PTR(ret);
		}
		EXPORT_SYMBOL_GPL(regulator_register);