Now that the media_device can be used by multiple drivers,
via devres, we need to be sure that it will be dropped only
when all drivers stop using it.
Signed-off-by: Mauro Carvalho Chehab <mche...@osg.samsung.com>
---
drivers/media/media-device.c | 48 +++++++++++++++++++++++++++++++-------------
include/media/media-device.h | 3 +++
2 files changed, 37 insertions(+), 14 deletions(-)
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index c32fa15cc76e..38e6c319fe6e 100644
--- a/drivers/media/media-device.c
+++ b/drivers/media/media-device.c
@@ -721,6 +721,15 @@ int __must_check __media_device_register(struct
media_device *mdev,
{
int ret;
+ /* Check if mdev was ever registered at all */
+ mutex_lock(&mdev->graph_mutex);
+ if (media_devnode_is_registered(&mdev->devnode)) {
+ kref_get(&mdev->kref);
+ mutex_unlock(&mdev->graph_mutex);
+ return 0;
+ }
+ kref_init(&mdev->kref);
+
/* Register the device node. */
mdev->devnode.fops = &media_device_fops;
mdev->devnode.parent = mdev->dev;
@@ -730,8 +739,10 @@ int __must_check __media_device_register(struct
media_device *mdev,
mdev->topology_version = 0;
ret = media_devnode_register(&mdev->devnode, owner);
- if (ret < 0)
+ if (ret < 0) {
+ media_devnode_unregister(&mdev->devnode);
return ret;
+ }
ret = device_create_file(&mdev->devnode.dev, &dev_attr_model);
if (ret < 0) {
@@ -739,6 +750,7 @@ int __must_check __media_device_register(struct
media_device *mdev,
return ret;
}
+ mutex_unlock(&mdev->graph_mutex);
dev_dbg(mdev->dev, "Media device registered\n");
return 0;
@@ -773,23 +785,15 @@ void media_device_unregister_entity_notify(struct
media_device *mdev,
}
EXPORT_SYMBOL_GPL(media_device_unregister_entity_notify);
-void media_device_unregister(struct media_device *mdev)
+static void do_media_device_unregister(struct kref *kref)
{
+ struct media_device *mdev;
struct media_entity *entity;
struct media_entity *next;
struct media_interface *intf, *tmp_intf;
struct media_entity_notify *notify, *nextp;
- if (mdev == NULL)
- return;
-
- mutex_lock(&mdev->graph_mutex);
-
- /* Check if mdev was ever registered at all */
- if (!media_devnode_is_registered(&mdev->devnode)) {
- mutex_unlock(&mdev->graph_mutex);
- return;
- }
+ mdev = container_of(kref, struct media_device, kref);
/* Remove all entities from the media device */
list_for_each_entry_safe(entity, next, &mdev->entities, graph_obj.list)
@@ -807,13 +811,26 @@ void media_device_unregister(struct media_device *mdev)
kfree(intf);
}
- mutex_unlock(&mdev->graph_mutex);
+ /* Check if mdev devnode was registered */
+ if (!media_devnode_is_registered(&mdev->devnode))
+ return;
device_remove_file(&mdev->devnode.dev, &dev_attr_model);
media_devnode_unregister(&mdev->devnode);
dev_dbg(mdev->dev, "Media device unregistered\n");
}
+
+void media_device_unregister(struct media_device *mdev)
+{
+ if (mdev == NULL)
+ return;
+
+ mutex_lock(&mdev->graph_mutex);
+ kref_put(&mdev->kref, do_media_device_unregister);
+ mutex_unlock(&mdev->graph_mutex);
+
+}
EXPORT_SYMBOL_GPL(media_device_unregister);
static void media_device_release_devres(struct device *dev, void *res)
@@ -825,13 +842,16 @@ struct media_device *media_device_get_devres(struct
device *dev)
struct media_device *mdev;
mdev = devres_find(dev, media_device_release_devres, NULL, NULL);
- if (mdev)
+ if (mdev) {
+ kref_get(&mdev->kref);
return mdev;
+ }
mdev = devres_alloc(media_device_release_devres,
sizeof(struct media_device), GFP_KERNEL);
if (!mdev)
return NULL;
+
return devres_get(dev, mdev, NULL, NULL);
}
EXPORT_SYMBOL_GPL(media_device_get_devres);
diff --git a/include/media/media-device.h b/include/media/media-device.h
index ca3871b853ba..73c16e6e6b6b 100644
--- a/include/media/media-device.h
+++ b/include/media/media-device.h
@@ -23,6 +23,7 @@
#ifndef _MEDIA_DEVICE_H
#define _MEDIA_DEVICE_H
+#include <linux/kref.h>
#include <linux/list.h>
#include <linux/mutex.h>
@@ -283,6 +284,7 @@ struct media_entity_notify {
* struct media_device - Media device
* @dev: Parent device
* @devnode: Media device node
+ * @kref: Object refcount
* @driver_name: Optional device driver name. If not set, calls to
* %MEDIA_IOC_DEVICE_INFO will return dev->driver->name.
* This is needed for USB drivers for example, as otherwise
@@ -347,6 +349,7 @@ struct media_device {
/* dev->driver_data points to this struct. */
struct device *dev;
struct media_devnode devnode;
+ struct kref kref;
char model[32];
char driver_name[32];
--
2.5.0
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