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authorHans Verkuil <hans.verkuil@cisco.com>2018-05-21 11:55:00 +0300
committerHans Verkuil <hans.verkuil@cisco.com>2018-08-14 15:43:40 +0200
commit5c83b2622e051fb37395bcde2f75a2e9d0926ab8 (patch)
tree45e7da8296a9a9fd3db7a55aa05cacb06128f252
parentd2fb12022600a210f62e9183b0ec0d952739a685 (diff)
RFC: media-requests: add debugfs nodereqv18-debugfs
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@cisco.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
-rw-r--r--drivers/media/media-device.c40
-rw-r--r--drivers/media/media-devnode.c17
-rw-r--r--drivers/media/media-request.c5
-rw-r--r--include/media/media-device.h11
-rw-r--r--include/media/media-devnode.h4
-rw-r--r--include/media/media-request.h2
6 files changed, 79 insertions, 0 deletions
diff --git a/drivers/media/media-device.c b/drivers/media/media-device.c
index d78e991bce46..7049e77d2115 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);
+#if IS_ENABLED(CONFIG_DEBUG_FS) && IS_ENABLED(CONFIG_VIDEO_ADV_DEBUG)
+/*
+ * 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
@@ -714,6 +731,8 @@ void media_device_init(struct media_device *mdev)
ida_init(&mdev->entity_internal_idx);
atomic_set(&mdev->request_id, 0);
+ atomic_set(&mdev->num_requests, 0);
+ atomic_set(&mdev->num_request_objects, 0);
dev_dbg(mdev->dev, "Media device initialized\n");
}
@@ -766,6 +785,26 @@ int __must_check __media_device_register(struct media_device *mdev,
dev_dbg(mdev->dev, "Media device registered\n");
+#if IS_ENABLED(CONFIG_DEBUG_FS) && IS_ENABLED(CONFIG_VIDEO_ADV_DEBUG)
+ 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);
@@ -843,6 +882,7 @@ 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 4b0ce8fde7c9..3292b8b3746f 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)
@@ -316,6 +317,7 @@ int media_request_alloc(struct media_device *mdev, int *alloc_fd)
snprintf(req->debug_str, sizeof(req->debug_str), "%u:%d",
atomic_inc_return(&mdev->request_id), fd);
+ atomic_inc(&mdev->num_requests);
dev_dbg(mdev->dev, "request: allocated %s\n", req->debug_str);
fd_install(fd, filp);
@@ -340,6 +342,7 @@ 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 *
@@ -403,6 +406,7 @@ int media_request_object_bind(struct media_request *req,
obj->req = req;
obj->ops = ops;
obj->priv = priv;
+ obj->mdev = req->mdev;
if (is_buffer)
list_add_tail(&obj->list, &req->objects);
@@ -410,6 +414,7 @@ int media_request_object_bind(struct media_request *req,
list_add(&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 c8ddbfe8b74c..00291e4086d9 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>
@@ -114,6 +115,10 @@ struct media_device_ops {
* @req_queue_mutex: Serialise the MEDIA_REQUEST_IOC_QUEUE ioctl w.r.t.
* other operations that stop or start streaming.
* @request_id: Used to generate unique request IDs
+ * @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
@@ -187,6 +192,12 @@ struct media_device {
struct mutex req_queue_mutex;
atomic_t request_id;
+ 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 ac02019c1d77..c913b998c88c 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;

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