diff options
| -rw-r--r-- | drivers/media/media-device.c | 15 | ||||
| -rw-r--r-- | drivers/media/media-devnode.c | 8 | ||||
| -rw-r--r-- | include/media/media-devnode.h | 16 |
3 files changed, 29 insertions, 10 deletions
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c index 33a99524216a..1795abeda658 100644 --- a/drivers/media/media-device.c +++ b/drivers/media/media-device.c @@ -732,6 +732,7 @@ int __must_check __media_device_register(struct media_device *mdev, if (ret < 0) { /* devnode free is handled in media_devnode_*() */ mdev->devnode = NULL; + media_devnode_unregister_prepare(devnode); media_devnode_unregister(devnode); return ret; } @@ -788,6 +789,9 @@ void media_device_unregister(struct media_device *mdev) return; } + /* Clear the devnode register bit to avoid races with media dev open */ + media_devnode_unregister_prepare(mdev->devnode); + /* Remove all entities from the media device */ list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list) __media_device_unregister_entity(entity); @@ -808,13 +812,10 @@ void media_device_unregister(struct media_device *mdev) dev_dbg(mdev->dev, "Media device unregistered\n"); - /* Check if mdev devnode was registered */ - if (media_devnode_is_registered(mdev->devnode)) { - device_remove_file(&mdev->devnode->dev, &dev_attr_model); - media_devnode_unregister(mdev->devnode); - /* devnode free is handled in media_devnode_*() */ - mdev->devnode = NULL; - } + device_remove_file(&mdev->devnode->dev, &dev_attr_model); + media_devnode_unregister(mdev->devnode); + /* devnode free is handled in media_devnode_*() */ + mdev->devnode = NULL; } EXPORT_SYMBOL_GPL(media_device_unregister); diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c index 5b605ff38daf..f2772ba6f611 100644 --- a/drivers/media/media-devnode.c +++ b/drivers/media/media-devnode.c @@ -287,7 +287,7 @@ cdev_add_error: return ret; } -void media_devnode_unregister(struct media_devnode *devnode) +void media_devnode_unregister_prepare(struct media_devnode *devnode) { /* Check if devnode was ever registered at all */ if (!media_devnode_is_registered(devnode)) @@ -295,6 +295,12 @@ void media_devnode_unregister(struct media_devnode *devnode) mutex_lock(&media_devnode_lock); clear_bit(MEDIA_FLAG_REGISTERED, &devnode->flags); + mutex_unlock(&media_devnode_lock); +} + +void media_devnode_unregister(struct media_devnode *devnode) +{ + mutex_lock(&media_devnode_lock); /* Delete the cdev on this minor as well */ cdev_del(&devnode->cdev); mutex_unlock(&media_devnode_lock); diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h index 5bb3b0e86d73..f0b7dd79fb92 100644 --- a/include/media/media-devnode.h +++ b/include/media/media-devnode.h @@ -126,14 +126,26 @@ int __must_check media_devnode_register(struct media_device *mdev, struct module *owner); /** + * media_devnode_unregister_prepare - clear the media device node register bit + * @devnode: the device node to prepare for unregister + * + * This clears the passed device register bit. Future open calls will be met + * with errors. Should be called before media_devnode_unregister() to avoid + * races with unregister and device file open calls. + * + * This function can safely be called if the device node has never been + * registered or has already been unregistered. + */ +void media_devnode_unregister_prepare(struct media_devnode *devnode); + +/** * media_devnode_unregister - unregister a media device node * @devnode: the device node to unregister * * This unregisters the passed device. Future open calls will be met with * errors. * - * This function can safely be called if the device node has never been - * registered or has already been unregistered. + * Should be called after media_devnode_unregister_prepare() */ void media_devnode_unregister(struct media_devnode *devnode); |