[media] dvb_usb_v2: register device even no remote keymap defined

It failed to register device when remote keymap was not set.
Fix it to register device even keymap is NULL. In that case
just skip remote registration.

Driver should set RC_MAP_EMPTY to enable remote in case of
there is remote receiver but default keymap is unknown.
Reported-by: pierigno <pierigno@gmail.com>
Signed-off-by: Antti Palosaari <crope@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/dvb/dvb-usb/af9015.c

@@ -1276,6 +1276,10 @@ static int af9015_get_rc_config(struct dvb_usb_device *d, struct dvb_usb_rc *rc)
 		}
 	}
 
+	/* load empty to enable rc */
+	if (!rc->map_name)
+		rc->map_name = RC_MAP_EMPTY;
+
 	rc->allowed_protos = RC_TYPE_NEC;
 	rc->query = af9015_rc_query;
 	rc->interval = 500;

drivers/media/dvb/dvb-usb/af9035.c

@@ -966,6 +966,10 @@ static int af9035_get_rc_config(struct dvb_usb_device *d, struct dvb_usb_rc *rc)
 
 		rc->query = af9035_rc_query;
 		rc->interval = 500;
+
+		/* load empty to enable rc */
+		if (!rc->map_name)
+			rc->map_name = RC_MAP_EMPTY;
 	}
 
 	return 0;

drivers/media/dvb/dvb-usb/dvb_usb.h

@@ -124,7 +124,7 @@ struct dvb_usb_driver_info {
  * @bulk_mode: device supports bulk mode for rc (disable polling mode)
  */
 struct dvb_usb_rc {
-	char *map_name;
+	const char *map_name;
 	u64 allowed_protos;
 	int (*change_protocol)(struct rc_dev *dev, u64 rc_type);
 	int (*query) (struct dvb_usb_device *d);

drivers/media/dvb/dvb-usb/dvb_usb_core.c

@@ -135,10 +135,15 @@ static int dvb_usbv2_remote_init(struct dvb_usb_device *d)
 	if (dvb_usbv2_disable_rc_polling || !d->props->get_rc_config)
 		return 0;
 
+	d->rc.map_name = d->rc_map;
 	ret = d->props->get_rc_config(d, &d->rc);
 	if (ret < 0)
 		goto err;
 
+	/* disable rc when there is no keymap defined */
+	if (!d->rc.map_name)
+		return 0;
+
 	dev = rc_allocate_device();
 	if (!dev) {
 		ret = -ENOMEM;
@@ -153,14 +158,11 @@ static int dvb_usbv2_remote_init(struct dvb_usb_device *d)
 	usb_to_input_id(d->udev, &dev->input_id);
 	/* TODO: likely RC-core should took const char * */
 	dev->driver_name = (char *) d->props->driver_name;
+	dev->map_name = d->rc.map_name;
 	dev->driver_type = d->rc.driver_type;
 	dev->allowed_protos = d->rc.allowed_protos;
 	dev->change_protocol = d->rc.change_protocol;
 	dev->priv = d;
-	if (d->rc.map_name)
-		dev->map_name = d->rc.map_name;
-	else
-		dev->map_name = d->rc_map;
 
 	ret = rc_register_device(dev);
 	if (ret < 0) {