V4L/DVB: dvb-usb: enable specifying a separate generic bulk ctrl response endpoint

Some DVB USB devices use a separate endpoint for responses to control
messages sent with bulk transfers via the generic_bulk_ctrl_endpoint.
When generic_bulk_ctrl_endpoint_response is set, it will be used instead
of the generic_bulk_ctrl_endpoint when reading usb responses in the
dvb_usb_generic_rw helper function.
Signed-off-by: Michael Krufky <mkrufky@kernellabs.com>
Reviewed-by: Patrick Boettcher <pboettcher@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

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

@@ -42,6 +42,8 @@ int dvb_usb_generic_rw(struct dvb_usb_device *d, u8 *wbuf, u16 wlen, u8 *rbuf,
 			msleep(delay_ms);
 
 		ret = usb_bulk_msg(d->udev,usb_rcvbulkpipe(d->udev,
+				d->props.generic_bulk_ctrl_endpoint_response ?
+				d->props.generic_bulk_ctrl_endpoint_response :
 				d->props.generic_bulk_ctrl_endpoint),rbuf,rlen,&actlen,
 				2000);
 

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

@@ -198,6 +198,12 @@ struct dvb_usb_adapter_properties {
  *  is non-zero, one can use dvb_usb_generic_rw and dvb_usb_generic_write-
  *  helper functions.
  *
+ * @generic_bulk_ctrl_endpoint_response: some DVB USB devices use a separate
+ *  endpoint for responses to control messages sent with bulk transfers via
+ *  the generic_bulk_ctrl_endpoint. When this is non-zero, this will be used
+ *  instead of the generic_bulk_ctrl_endpoint when reading usb responses in
+ *  the dvb_usb_generic_rw helper function.
+ *
  * @num_device_descs: number of struct dvb_usb_device_description in @devices
  * @devices: array of struct dvb_usb_device_description compatibles with these
  *  properties.
@@ -239,6 +245,7 @@ struct dvb_usb_device_properties {
 	struct i2c_algorithm *i2c_algo;
 
 	int generic_bulk_ctrl_endpoint;
+	int generic_bulk_ctrl_endpoint_response;
 
 	int num_device_descs;
 	struct dvb_usb_device_description devices[12];