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Diffstat (limited to 'drivers/media/v4l2-core/v4l2-device.c')
-rw-r--r--drivers/media/v4l2-core/v4l2-device.c18
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/media/v4l2-core/v4l2-device.c b/drivers/media/v4l2-core/v4l2-device.c
index 02d1b6327117..015f92aab44a 100644
--- a/drivers/media/v4l2-core/v4l2-device.c
+++ b/drivers/media/v4l2-core/v4l2-device.c
@@ -158,7 +158,17 @@ int v4l2_device_register_subdev(struct v4l2_device *v4l2_dev,
/* Warn if we apparently re-register a subdev */
WARN_ON(sd->v4l2_dev != NULL);
- if (!try_module_get(sd->owner))
+ /*
+ * The reason to acquire the module here is to avoid unloading
+ * a module of sub-device which is registered to a media
+ * device. To make it possible to unload modules for media
+ * devices that also register sub-devices, do not
+ * try_module_get() such sub-device owners.
+ */
+ sd->owner_v4l2_dev = v4l2_dev->dev && v4l2_dev->dev->driver &&
+ sd->owner == v4l2_dev->dev->driver->owner;
+
+ if (!sd->owner_v4l2_dev && !try_module_get(sd->owner))
return -ENODEV;
sd->v4l2_dev = v4l2_dev;
@@ -192,7 +202,8 @@ error_unregister:
if (sd->internal_ops && sd->internal_ops->unregistered)
sd->internal_ops->unregistered(sd);
error_module:
- module_put(sd->owner);
+ if (!sd->owner_v4l2_dev)
+ module_put(sd->owner);
sd->v4l2_dev = NULL;
return err;
}
@@ -280,6 +291,7 @@ void v4l2_device_unregister_subdev(struct v4l2_subdev *sd)
}
#endif
video_unregister_device(sd->devnode);
- module_put(sd->owner);
+ if (!sd->owner_v4l2_dev)
+ module_put(sd->owner);
}
EXPORT_SYMBOL_GPL(v4l2_device_unregister_subdev);