PM / devfreq: Fix devfreq_remove_device() to improve the sequence of resource free (585fc83e) · Commits · 戴 / test

This patch modify devfreq_remove_device() to improve the sequence of resource free. If executing existing devfreq_remove_device(), this function always executes _remove_devfreq() twice. In result, second _remove_devfreq() always return error value. So, This patch resolves complicated function sequence as following: [Flow sequence before modification] devfreq_remove_device() _remove_devfreq(devfreq, false) kfree(devfreq); /* Free devfreq */ if (!skip ...) { /* skip is false */ device_unregister(&devfreq->dev) put_device(&devfreq->dev); ... dev->release() devfreq_dev_release() _remove_devfreq(devfreq, true) <- Recall to free devfreq /* * Always return error without freeing resource because * already _remove_devfreq() frees the memory of devfreq. */ } [Flow sequence after modification] devfreq_remove_device device_unregister(&devfreq->dev) put_device(&devfreq->dev); .. dev->release() devfreq_dev_release() _remove_devfreq() kfree(devfreq); /* Free devfreq */ Signed-off-by:

Chanwoo Choi <cw00.choi@samsung.com> [Merge conflict resolved by MyungJoo] Signed-off-by:

MyungJoo Ham <myungjoo.ham@samsung.com>

drivers/devfreq/devfreq.c

+4 −10

Original line number	Diff line number	Diff line
		@@ -394,7 +394,7 @@ static int devfreq_notifier_call(struct notifier_block *nb, unsigned long type,
		* @devfreq: the devfreq struct
		* @skip: skip calling device_unregister().
		*/
		static void _remove_devfreq(struct devfreq *devfreq, bool skip)
		static void _remove_devfreq(struct devfreq *devfreq)
		{
		mutex_lock(&devfreq_list_lock);
		if (IS_ERR(find_device_devfreq(devfreq->dev.parent))) {
		@@ -412,11 +412,6 @@ static void _remove_devfreq(struct devfreq *devfreq, bool skip)
		if (devfreq->profile->exit)
		devfreq->profile->exit(devfreq->dev.parent);

		if (!skip && get_device(&devfreq->dev)) {
		device_unregister(&devfreq->dev);
		put_device(&devfreq->dev);
		}

		mutex_destroy(&devfreq->lock);
		kfree(devfreq);
		}
		@@ -426,14 +421,12 @@ static void _remove_devfreq(struct devfreq *devfreq, bool skip)
		* @dev: the devfreq device
		*
		* This calls _remove_devfreq() if _remove_devfreq() is not called.
		* Note that devfreq_dev_release() could be called by _remove_devfreq() as
		* well as by others unregistering the device.
		*/
		static void devfreq_dev_release(struct device *dev)
		{
		struct devfreq *devfreq = to_devfreq(dev);

		_remove_devfreq(devfreq, true);
		_remove_devfreq(devfreq);
		}

		/**
		@@ -544,7 +537,8 @@ int devfreq_remove_device(struct devfreq *devfreq)
		if (!devfreq)
		return -EINVAL;

		_remove_devfreq(devfreq, false);
		device_unregister(&devfreq->dev);
		put_device(&devfreq->dev);

		return 0;
		}

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