xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

media: v4l2-subdev: handle module refcounting here

Browse Source 
The module ownership refcounting was done in media_entity_get/put,
but that was very confusing and it did not work either in case an
application had a v4l-subdevX device open and the module was
unbound. When the v4l-subdevX device was closed the media_entity_put
was never called and the module refcount was left one too high, making
it impossible to unload it.

Since v4l2-subdev.c was the only place where media_entity_get/put was
called, just move the functionality to v4l2-subdev.c and drop those
confusing entity functions.

Store the module in subdev_fh so module_put no longer depends on
the media_entity struct.

Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Hans Verkuil
2019-03-01 06:11:27 -05:00
committed by Mauro Carvalho Chehab
parent 0e43734d4c
commit 218bf10e39
4 changed files with 11 additions and 65 deletions
Download Patch File Download Diff File Expand all files Collapse all files

28
drivers/media/media-entity.c
View File

@@ -17,7 +17,6 @@
*/
#include <linux/bitmap.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/slab.h>
#include <media/media-entity.h>
@@ -587,33 +586,6 @@ void media_pipeline_stop(struct media_entity *entity)
}
EXPORT_SYMBOL_GPL(media_pipeline_stop);
/* -----------------------------------------------------------------------------
* Module use count
*/
struct media_entity *media_entity_get(struct media_entity *entity)
{
if (entity == NULL)
return NULL;
if (entity->graph_obj.mdev->dev &&
!try_module_get(entity->graph_obj.mdev->dev->driver->owner))
return NULL;
return entity;
}
EXPORT_SYMBOL_GPL(media_entity_get);
void media_entity_put(struct media_entity *entity)
{
if (entity == NULL)
return;
if (entity->graph_obj.mdev->dev)
module_put(entity->graph_obj.mdev->dev->driver->owner);
}
EXPORT_SYMBOL_GPL(media_entity_put);
/* -----------------------------------------------------------------------------
* Links management
*/