diff options
| -rw-r--r-- | drivers/media/video/v4l2-dev.c | 10 | ||||
| -rw-r--r-- | drivers/media/video/v4l2-device.c | 16 | ||||
| -rw-r--r-- | include/media/v4l2-device.h | 11 |
3 files changed, 37 insertions, 0 deletions
diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 6b1ef85d8cc..1898099ec65 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -143,6 +143,7 @@ static inline void video_put(struct video_device *vdev) static void v4l2_device_release(struct device *cd) { struct video_device *vdev = to_video_device(cd); + struct v4l2_device *v4l2_dev = vdev->v4l2_dev; mutex_lock(&videodev_lock); if (video_device[vdev->minor] != vdev) { @@ -169,6 +170,10 @@ static void v4l2_device_release(struct device *cd) /* Release video_device and perform other cleanups as needed. */ vdev->release(vdev); + + /* Decrease v4l2_device refcount */ + if (v4l2_dev) + v4l2_device_put(v4l2_dev); } static struct class video_class = { @@ -676,6 +681,11 @@ int __video_register_device(struct video_device *vdev, int type, int nr, if (nr != -1 && nr != vdev->num && warn_if_nr_in_use) printk(KERN_WARNING "%s: requested %s%d, got %s\n", __func__, name_base, nr, video_device_node_name(vdev)); + + /* Increase v4l2_device refcount */ + if (vdev->v4l2_dev) + v4l2_device_get(vdev->v4l2_dev); + #if defined(CONFIG_MEDIA_CONTROLLER) /* Part 5: Register the entity. */ if (vdev->v4l2_dev && vdev->v4l2_dev->mdev) { diff --git a/drivers/media/video/v4l2-device.c b/drivers/media/video/v4l2-device.c index fd7a445ce34..5aeaf876ba9 100644 --- a/drivers/media/video/v4l2-device.c +++ b/drivers/media/video/v4l2-device.c @@ -37,6 +37,7 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) spin_lock_init(&v4l2_dev->lock); mutex_init(&v4l2_dev->ioctl_lock); v4l2_prio_init(&v4l2_dev->prio); + kref_init(&v4l2_dev->ref); v4l2_dev->dev = dev; if (dev == NULL) { /* If dev == NULL, then name must be filled in by the caller */ @@ -54,6 +55,21 @@ int v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev) } EXPORT_SYMBOL_GPL(v4l2_device_register); +static void v4l2_device_release(struct kref *ref) +{ + struct v4l2_device *v4l2_dev = + container_of(ref, struct v4l2_device, ref); + + if (v4l2_dev->release) + v4l2_dev->release(v4l2_dev); +} + +int v4l2_device_put(struct v4l2_device *v4l2_dev) +{ + return kref_put(&v4l2_dev->ref, v4l2_device_release); +} +EXPORT_SYMBOL_GPL(v4l2_device_put); + int v4l2_device_set_name(struct v4l2_device *v4l2_dev, const char *basename, atomic_t *instance) { diff --git a/include/media/v4l2-device.h b/include/media/v4l2-device.h index 3b723283da2..bd102cf509a 100644 --- a/include/media/v4l2-device.h +++ b/include/media/v4l2-device.h @@ -60,8 +60,19 @@ struct v4l2_device { struct v4l2_prio_state prio; /* BKL replacement mutex. Temporary solution only. */ struct mutex ioctl_lock; + /* Keep track of the references to this struct. */ + struct kref ref; + /* Release function that is called when the ref count goes to 0. */ + void (*release)(struct v4l2_device *v4l2_dev); }; +static inline void v4l2_device_get(struct v4l2_device *v4l2_dev) +{ + kref_get(&v4l2_dev->ref); +} + +int v4l2_device_put(struct v4l2_device *v4l2_dev); + /* Initialize v4l2_dev and make dev->driver_data point to v4l2_dev. dev may be NULL in rare cases (ISA devices). In that case you must fill in the v4l2_dev->name field before calling this function. */ |