V4L/DVB (4657): Power control of the device for dual board

Corrected power control of the device for dual boards
Signed-off-by: Patrick Boettcher <pb@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

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

@@ -197,8 +197,13 @@ static struct dvb_usb_device_description * dvb_usb_find_device(struct usb_device
 
 int dvb_usb_device_power_ctrl(struct dvb_usb_device *d, int onoff)
 {
-	if (d->powered == !onoff) {
-		d->powered = onoff;
+	if (onoff)
+		d->powered++;
+	else
+		d->powered--;
+
+	if (d->powered == 0 || (onoff && d->powered == 1)) { // when switching from 1 to 0 or from 0 to 1
+		deb_info("power control: %d\n", onoff);
 		if (d->props.power_ctrl)
 			return d->props.power_ctrl(d, onoff);
 	}

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

@@ -325,6 +325,8 @@ struct dvb_usb_adapter {
  * @desc: pointer to the device's struct dvb_usb_device_description.
  * @state: initialization and runtime state of the device.
  *
+ * @powered: indicated whether the device is power or not.
+ *  Powered is in/decremented for each call to modify the state.
  * @udev: pointer to the device's struct usb_device.
  *
  * @usb_mutex: semaphore of USB control messages (reading needs two messages)