| From a2151374230820a3a6e654f2998b2a44dbfae4e1 Mon Sep 17 00:00:00 2001 |
| From: Jon Hunter <jonathanh@nvidia.com> |
| Date: Wed, 30 Mar 2016 17:09:13 +0100 |
| Subject: regulator: Fix deadlock during regulator registration |
| |
| From: Jon Hunter <jonathanh@nvidia.com> |
| |
| commit a2151374230820a3a6e654f2998b2a44dbfae4e1 upstream. |
| |
| Commit 5e3ca2b349b1 ("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> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/regulator/core.c | 10 +++++----- |
| 1 file changed, 5 insertions(+), 5 deletions(-) |
| |
| --- a/drivers/regulator/core.c |
| +++ b/drivers/regulator/core.c |
| @@ -3991,12 +3991,11 @@ regulator_register(const struct regulato |
| } |
| |
| rdev_init_debugfs(rdev); |
| + mutex_unlock(®ulator_list_mutex); |
| |
| /* try to resolve regulators supply since a new one was registered */ |
| class_for_each_device(®ulator_class, NULL, NULL, |
| regulator_register_resolve_supply); |
| -out: |
| - mutex_unlock(®ulator_list_mutex); |
| kfree(config); |
| return rdev; |
| |
| @@ -4007,15 +4006,16 @@ scrub: |
| 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(®ulator_list_mutex); |
| + kfree(config); |
| + return ERR_PTR(ret); |
| } |
| EXPORT_SYMBOL_GPL(regulator_register); |
| |