Em Sat, 4 Aug 2018 14:45:26 +0200
Hans Verkuil <hverkuil@xxxxxxxxx> escreveu:
> From: Hans Verkuil <hans.verkuil@xxxxxxxxx>
>
> Keep track of the number of requests and request objects of a media
> device. Helps to verify that all request-related memory is freed.
>
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> drivers/media/media-device.c | 41 +++++++++++++++++++++++++++++++++++
> drivers/media/media-devnode.c | 17 +++++++++++++++
> drivers/media/media-request.c | 5 +++++
> include/media/media-device.h | 11 ++++++++++
> include/media/media-devnode.h | 4 ++++
> include/media/media-request.h | 2 ++
> 6 files changed, 80 insertions(+)
>
> diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
> index 4b9a8de05562..28a891b53886 100644
> --- a/drivers/media/media-device.c
> +++ b/drivers/media/media-device.c
> @@ -691,6 +691,23 @@ void media_device_unregister_entity(struct media_entity *entity)
> }
> EXPORT_SYMBOL_GPL(media_device_unregister_entity);
>
> +#ifdef CONFIG_DEBUG_FS
Patch itself looks good. Yet, perhaps we could request both
CONFIG_DEBUG_FS and CONFIG_VIDEO_ADV_DEBUG.
Also, instead of ifdef, please use IS_ENABLED for DEBUG_FS. That tends
to be safer long term.
With that:
Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
> +/*
> + * Log the state of media requests.
> + * Very useful for debugging.
> + */
> +static int media_device_requests(struct seq_file *file, void *priv)
> +{
> + struct media_device *dev = dev_get_drvdata(file->private);
> +
> + seq_printf(file, "number of requests: %d\n",
> + atomic_read(&dev->num_requests));
> + seq_printf(file, "number of request objects: %d\n",
> + atomic_read(&dev->num_request_objects));
> + return 0;
> +}
> +#endif
> +
> /**
> * media_device_init() - initialize a media device
> * @mdev: The media device
> @@ -713,6 +730,9 @@ void media_device_init(struct media_device *mdev)
> mutex_init(&mdev->graph_mutex);
> ida_init(&mdev->entity_internal_idx);
>
> + atomic_set(&mdev->num_requests, 0);
> + atomic_set(&mdev->num_request_objects, 0);
> +
> dev_dbg(mdev->dev, "Media device initialized\n");
> }
> EXPORT_SYMBOL_GPL(media_device_init);
> @@ -764,6 +784,26 @@ int __must_check __media_device_register(struct media_device *mdev,
>
> dev_dbg(mdev->dev, "Media device registered\n");
>
> +#ifdef CONFIG_DEBUG_FS
> + if (!media_top_dir)
> + return 0;
> +
> + mdev->media_dir = debugfs_create_dir(dev_name(&devnode->dev),
> + media_top_dir);
> + if (IS_ERR_OR_NULL(mdev->media_dir)) {
> + dev_warn(mdev->dev, "Failed to create debugfs dir\n");
> + return 0;
> + }
> + mdev->requests_file = debugfs_create_devm_seqfile(&devnode->dev,
> + "requests", mdev->media_dir, media_device_requests);
> + if (IS_ERR_OR_NULL(mdev->requests_file)) {
> + dev_warn(mdev->dev, "Failed to create requests file\n");
> + debugfs_remove_recursive(mdev->media_dir);
> + mdev->media_dir = NULL;
> + return 0;
> + }
> +#endif
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(__media_device_register);
> @@ -841,6 +881,7 @@ void media_device_unregister(struct media_device *mdev)
>
> dev_dbg(mdev->dev, "Media device unregistered\n");
>
> + debugfs_remove_recursive(mdev->media_dir);
> device_remove_file(&mdev->devnode->dev, &dev_attr_model);
> media_devnode_unregister(mdev->devnode);
> /* devnode free is handled in media_devnode_*() */
> diff --git a/drivers/media/media-devnode.c b/drivers/media/media-devnode.c
> index 6b87a721dc49..4358ed22f208 100644
> --- a/drivers/media/media-devnode.c
> +++ b/drivers/media/media-devnode.c
> @@ -53,6 +53,12 @@ static dev_t media_dev_t;
> static DEFINE_MUTEX(media_devnode_lock);
> static DECLARE_BITMAP(media_devnode_nums, MEDIA_NUM_DEVICES);
>
> +/*
> + * debugfs
> + */
> +struct dentry *media_top_dir;
> +
> +
> /* Called when the last user of the media device exits. */
> static void media_devnode_release(struct device *cd)
> {
> @@ -259,6 +265,8 @@ int __must_check media_devnode_register(struct media_device *mdev,
> goto cdev_add_error;
> }
>
> + dev_set_drvdata(&devnode->dev, mdev);
> +
> /* Part 4: Activate this minor. The char device can now be used. */
> set_bit(MEDIA_FLAG_REGISTERED, &devnode->flags);
>
> @@ -310,6 +318,14 @@ static int __init media_devnode_init(void)
> return ret;
> }
>
> +#ifdef CONFIG_DEBUG_FS
> + media_top_dir = debugfs_create_dir("media", NULL);
> + if (IS_ERR_OR_NULL(media_top_dir)) {
> + pr_warn("Failed to create debugfs media dir\n");
> + media_top_dir = NULL;
> + }
> +#endif
> +
> ret = bus_register(&media_bus_type);
> if (ret < 0) {
> unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
> @@ -322,6 +338,7 @@ static int __init media_devnode_init(void)
>
> static void __exit media_devnode_exit(void)
> {
> + debugfs_remove_recursive(media_top_dir);
> bus_unregister(&media_bus_type);
> unregister_chrdev_region(media_dev_t, MEDIA_NUM_DEVICES);
> }
> diff --git a/drivers/media/media-request.c b/drivers/media/media-request.c
> index a5b70a4e613b..8ba97a9c4bf1 100644
> --- a/drivers/media/media-request.c
> +++ b/drivers/media/media-request.c
> @@ -72,6 +72,7 @@ static void media_request_release(struct kref *kref)
> mdev->ops->req_free(req);
> else
> kfree(req);
> + atomic_dec(&mdev->num_requests);
> }
>
> void media_request_put(struct media_request *req)
> @@ -318,6 +319,7 @@ int media_request_alloc(struct media_device *mdev,
> get_task_comm(comm, current);
> snprintf(req->debug_str, sizeof(req->debug_str), "%s:%d",
> comm, fd);
> + atomic_inc(&mdev->num_requests);
> dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
>
> fd_install(fd, filp);
> @@ -342,6 +344,7 @@ static void media_request_object_release(struct kref *kref)
> if (WARN_ON(req))
> media_request_object_unbind(obj);
> obj->ops->release(obj);
> + atomic_dec(&obj->mdev->num_request_objects);
> }
>
> struct media_request_object *
> @@ -405,10 +408,12 @@ int media_request_object_bind(struct media_request *req,
> obj->req = req;
> obj->ops = ops;
> obj->priv = priv;
> + obj->mdev = req->mdev;
>
> list_add_tail(&obj->list, &req->objects);
> req->num_incomplete_objects++;
> ret = 0;
> + atomic_inc(&obj->mdev->num_request_objects);
>
> unlock:
> spin_unlock_irqrestore(&req->lock, flags);
> diff --git a/include/media/media-device.h b/include/media/media-device.h
> index 110b89567671..2de0606938d4 100644
> --- a/include/media/media-device.h
> +++ b/include/media/media-device.h
> @@ -21,6 +21,7 @@
>
> #include <linux/list.h>
> #include <linux/mutex.h>
> +#include <linux/atomic.h>
>
> #include <media/media-devnode.h>
> #include <media/media-entity.h>
> @@ -107,6 +108,10 @@ struct media_device_ops {
> * @ops: Operation handler callbacks
> * @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
> * other operations that stop or start streaming.
> + * @num_requests: number of associated requests
> + * @num_request_objects: number of associated request objects
> + * @media_dir: DebugFS media directory
> + * @requests_file: DebugFS requests file
> *
> * This structure represents an abstract high-level media device. It allows easy
> * access to entities and provides basic media device-level support. The
> @@ -179,6 +184,12 @@ struct media_device {
> const struct media_device_ops *ops;
>
> struct mutex req_queue_mutex;
> + atomic_t num_requests;
> + atomic_t num_request_objects;
> +
> + /* debugfs */
> + struct dentry *media_dir;
> + struct dentry *requests_file;
> };
>
> /* We don't need to include pci.h or usb.h here */
> diff --git a/include/media/media-devnode.h b/include/media/media-devnode.h
> index dc2f64e1b08f..984b62b634d3 100644
> --- a/include/media/media-devnode.h
> +++ b/include/media/media-devnode.h
> @@ -28,9 +28,13 @@
> #include <linux/fs.h>
> #include <linux/device.h>
> #include <linux/cdev.h>
> +#include <linux/debugfs.h>
>
> struct media_device;
>
> +/* DebugFS top-level media directory */
> +extern struct dentry *media_top_dir;
> +
> /*
> * Flag to mark the media_devnode struct as registered. Drivers must not touch
> * this flag directly, it will be set and cleared by media_devnode_register and
> diff --git a/include/media/media-request.h b/include/media/media-request.h
> index fd08d7a431a1..76727d4a89c3 100644
> --- a/include/media/media-request.h
> +++ b/include/media/media-request.h
> @@ -210,6 +210,7 @@ struct media_request_object_ops {
> * struct media_request_object - An opaque object that belongs to a media
> * request
> *
> + * @mdev: Media device this object belongs to
> * @ops: object's operations
> * @priv: object's priv pointer
> * @req: the request this object belongs to (can be NULL)
> @@ -221,6 +222,7 @@ struct media_request_object_ops {
> * another struct that contains the actual data for this request object.
> */
> struct media_request_object {
> + struct media_device *mdev;
> const struct media_request_object_ops *ops;
> void *priv;
> struct media_request *req;
Thanks,
Mauro
