break;
        }
 
-       return -ENODEV;
+       return 0;
 }
 
 static int af9035_frontend_callback(void *adapter_priv, int component,
        struct i2c_adapter *adap = adapter_priv;
        struct dvb_usb_device *d = i2c_get_adapdata(adap);
 
+       dev_dbg(&d->udev->dev, "%s: component=%d cmd=%d arg=%d\n",
+                       __func__, component, cmd, arg);
+
        switch (component) {
        case DVB_FRONTEND_COMPONENT_TUNER:
                return af9035_tuner_callback(d, cmd, arg);
                break;
        }
 
-       return -EINVAL;
+       return 0;
 }
 
 static int af9035_frontend_attach(struct dvb_usb_adapter *adap)