diff options
Diffstat (limited to 'include/media/dvbdev.h')
| -rw-r--r-- | include/media/dvbdev.h | 38 |
1 files changed, 23 insertions, 15 deletions
diff --git a/include/media/dvbdev.h b/include/media/dvbdev.h index 2f6b0861322a..29d25c8a6f13 100644 --- a/include/media/dvbdev.h +++ b/include/media/dvbdev.h @@ -87,7 +87,11 @@ struct dvb_frontend; * @device: pointer to struct device * @module: pointer to struct module * @mfe_shared: indicates mutually exclusive frontends. - * Use of this flag is currently deprecated. + * 1 = legacy exclusion behavior: blocking any open() call + * 2 = enhanced exclusion behavior, emulating the standard + * behavior of busy frontends: allowing read-only sharing + * and otherwise returning immediately with -EBUSY when any + * of the frontends is already opened with write access. * @mfe_dvbdev: Frontend device in use, in the case of MFE * @mfe_lock: Lock to prevent using the other frontends when MFE is * used. @@ -126,6 +130,7 @@ struct dvb_adapter { * struct dvb_device - represents a DVB device node * * @list_head: List head with all DVB devices + * @ref: reference counter * @fops: pointer to struct file_operations * @adapter: pointer to the adapter that holds this device node * @type: type of the device, as defined by &enum dvb_device_type. @@ -156,6 +161,7 @@ struct dvb_adapter { */ struct dvb_device { struct list_head list_head; + struct kref ref; const struct file_operations *fops; struct dvb_adapter *adapter; enum dvb_device_type type; @@ -188,6 +194,20 @@ struct dvb_device { }; /** + * dvb_device_get - Increase dvb_device reference + * + * @dvbdev: pointer to struct dvb_device + */ +struct dvb_device *dvb_device_get(struct dvb_device *dvbdev); + +/** + * dvb_device_put - Decrease dvb_device reference + * + * @dvbdev: pointer to struct dvb_device + */ +void dvb_device_put(struct dvb_device *dvbdev); + +/** * dvb_register_adapter - Registers a new DVB adapter * * @adap: pointer to struct dvb_adapter @@ -231,29 +251,17 @@ int dvb_register_device(struct dvb_adapter *adap, /** * dvb_remove_device - Remove a registered DVB device * - * This does not free memory. To do that, call dvb_free_device(). + * This does not free memory. dvb_free_device() will do that when + * reference counter is empty * * @dvbdev: pointer to struct dvb_device */ void dvb_remove_device(struct dvb_device *dvbdev); -/** - * dvb_free_device - Free memory occupied by a DVB device. - * - * Call dvb_unregister_device() before calling this function. - * - * @dvbdev: pointer to struct dvb_device - */ -void dvb_free_device(struct dvb_device *dvbdev); /** * dvb_unregister_device - Unregisters a DVB device * - * This is a combination of dvb_remove_device() and dvb_free_device(). - * Using this function is usually a mistake, and is often an indicator - * for a use-after-free bug (when a userspace process keeps a file - * handle to a detached device). - * * @dvbdev: pointer to struct dvb_device */ void dvb_unregister_device(struct dvb_device *dvbdev); |