Currently only very few drivers actually use video_device nodes, embedded
in struct v4l2_subdev. Allocate these nodes dynamically for those drivers
to save memory for the rest.
Signed-off-by: Guennadi Liakhovetski <g.liakhovet...@gmx.de>
---
Only compile tested. Please, give it a spin on affected hardware.
drivers/media/video/v4l2-device.c | 28 +++++++++++++++++++++++++---
include/media/v4l2-subdev.h | 10 ++++++++--
2 files changed, 33 insertions(+), 5 deletions(-)
diff --git a/drivers/media/video/v4l2-device.c
b/drivers/media/video/v4l2-device.c
index c72856c..0c0f6ba 100644
--- a/drivers/media/video/v4l2-device.c
+++ b/drivers/media/video/v4l2-device.c
@@ -21,6 +21,7 @@
#include <linux/types.h>
#include <linux/ioctl.h>
#include <linux/i2c.h>
+#include <linux/slab.h>
#if defined(CONFIG_SPI)
#include <linux/spi/spi.h>
#endif
@@ -194,6 +195,7 @@ EXPORT_SYMBOL_GPL(v4l2_device_register_subdev);
int v4l2_device_register_subdev_nodes(struct v4l2_device *v4l2_dev)
{
struct video_device *vdev;
+ struct v4l2_devnode *node;
struct v4l2_subdev *sd;
int err;
@@ -204,7 +206,13 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device
*v4l2_dev)
if (!(sd->flags & V4L2_SUBDEV_FL_HAS_DEVNODE))
continue;
- vdev = &sd->devnode;
+ node = kzalloc(sizeof(*node), GFP_KERNEL);
+ if (!node) {
+ err = -ENOMEM;
+ goto clean_up;
+ }
+ vdev = &node->vdev;
+
strlcpy(vdev->name, sd->name, sizeof(vdev->name));
vdev->v4l2_dev = v4l2_dev;
vdev->fops = &v4l2_subdev_fops;
@@ -213,13 +221,25 @@ int v4l2_device_register_subdev_nodes(struct v4l2_device
*v4l2_dev)
err = __video_register_device(vdev, VFL_TYPE_SUBDEV, -1, 1,
sd->owner);
if (err < 0)
- return err;
+ goto clean_up;
#if defined(CONFIG_MEDIA_CONTROLLER)
sd->entity.v4l.major = VIDEO_MAJOR;
sd->entity.v4l.minor = vdev->minor;
#endif
+ sd->devnode = node;
}
return 0;
+
+clean_up:
+ list_for_each_entry(sd, &v4l2_dev->subdevs, list) {
+ if (!sd->devnode)
+ break;
+ video_unregister_device(&sd->devnode->vdev);
+ kfree(sd->devnode);
+ sd->devnode = NULL;
+ }
+
+ return err;
}
EXPORT_SYMBOL_GPL(v4l2_device_register_subdev_nodes);
@@ -245,7 +265,9 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
if (v4l2_dev->mdev)
media_device_unregister_entity(&sd->entity);
#endif
- video_unregister_device(&sd->devnode);
+ video_unregister_device(&sd->devnode->vdev);
+ kfree(sd->devnode);
+ sd->devnode = NULL;
module_put(sd->owner);
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);
diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
index 257da1a..6e958df 100644
--- a/include/media/v4l2-subdev.h
+++ b/include/media/v4l2-subdev.h
@@ -510,6 +510,12 @@ struct v4l2_subdev_internal_ops {
/* Set this flag if this subdev generates events. */
#define V4L2_SUBDEV_FL_HAS_EVENTS (1U << 3)
+/* video_device with a reverse lookup */
+struct v4l2_devnode {
+ struct v4l2_subdev *sd;
+ struct video_device vdev;
+};
+
/* Each instance of a subdev driver should create this struct, either
stand-alone or embedded in a larger struct.
*/
@@ -534,13 +540,13 @@ struct v4l2_subdev {
void *dev_priv;
void *host_priv;
/* subdev device node */
- struct video_device devnode;
+ struct v4l2_devnode *devnode;
};
#define media_entity_to_v4l2_subdev(ent) \
container_of(ent, struct v4l2_subdev, entity)
#define vdev_to_v4l2_subdev(vdev) \
- container_of(vdev, struct v4l2_subdev, devnode)
+ (container_of(vdev, struct v4l2_devnode, vdev)->sd)
/*
* Used for storing subdev information per file handle
--
1.7.2.5
--
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