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Commit 29c128cf authored by David Collins's avatar David Collins
Browse files

regulator: core: avoid deadlock in QTI addition to regulator_unregister() 



regulator_unregister() calls rdev_free_qti_debugfs() with the
regulator_list_mutex held.  rdev_free_qti_debugfs() then calls
regulator_put() which attempts to lock regulator_list_mutex again.
This leads to deadlock.

Modify regulator_unregister() and rdev_free_qti_debugfs() so that
mutex deadlock cannot occur.

Change-Id: I12bb4c704f7d9332e790c707aba854e224474bdb
Signed-off-by: default avatarDavid Collins <collinsd@codeaurora.org>
parent 17439c2c

drivers/regulator/core.c

+2 −3
Original line number Original line Diff line number Diff line
@@ -5045,9 +5045,8 @@ DEFINE_DEBUGFS_ATTRIBUTE(reg_set_load_fops, reg_debug_mode_get, 
static void rdev_free_qti_debugfs(struct regulator_dev *rdev)

static void rdev_free_qti_debugfs(struct regulator_dev *rdev)

{

{

	if (!IS_ERR_OR_NULL(rdev)) {

	if (!IS_ERR_OR_NULL(rdev)) {

		if (rdev->debug_consumer)

			rdev->debug_consumer->debugfs = NULL;

		regulator_put(rdev->debug_consumer);

		regulator_put(rdev->debug_consumer);

		rdev->debug_consumer = NULL;

	}

	}

}

}
@@ -5658,11 +5657,11 @@ void regulator_unregister(struct regulator_dev *rdev) 
	}

	}





	flush_work(&rdev->disable_work.work);

	flush_work(&rdev->disable_work.work);

	rdev_free_qti_debugfs(rdev);





	mutex_lock(&regulator_list_mutex);

	mutex_lock(&regulator_list_mutex);





	debugfs_remove_recursive(rdev->debugfs);

	debugfs_remove_recursive(rdev->debugfs);

	rdev_free_qti_debugfs(rdev);

	WARN_ON(rdev->open_count);

	WARN_ON(rdev->open_count);

	regulator_remove_coupling(rdev);

	regulator_remove_coupling(rdev);

	unset_regulator_supplies(rdev);

	unset_regulator_supplies(rdev);