From 585fc83ece43be63d5775e536f855db33dd752cf Mon Sep 17 00:00:00 2001 From: Chanwoo Choi Date: Fri, 9 May 2014 16:43:07 +0900 Subject: PM / devfreq: Fix devfreq_remove_device() to improve the sequence of resource free 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 [Merge conflict resolved by MyungJoo] Signed-off-by: MyungJoo Ham --- drivers/devfreq/devfreq.c | 14 ++++---------- 1 file changed, 4 insertions(+), 10 deletions(-) (limited to 'drivers/devfreq') diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index 2042ec3656ba..af4af7708574 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -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; } -- cgit v1.2.3-59-g8ed1b