return USBVISION_IS_OPERATIONAL(usbvision);
 }
 
+int usbvision_set_alternate(struct usb_usbvision *dev)
+{
+       int errCode, prev_alt = dev->ifaceAlt;
+       int i;
+
+       dev->ifaceAlt=0;
+       for(i=0;i< dev->num_alt; i++)
+               if(dev->alt_max_pkt_size[i]>dev->alt_max_pkt_size[dev->ifaceAlt])
+                       dev->ifaceAlt=i;
+
+       if (dev->ifaceAlt != prev_alt) {
+               dev->isocPacketSize = dev->alt_max_pkt_size[dev->ifaceAlt];
+               PDEBUG(DBG_FUNC,"setting alternate %d with wMaxPacketSize=%u", dev->ifaceAlt,dev->isocPacketSize);
+               errCode = usb_set_interface(dev->dev, dev->iface, dev->ifaceAlt);
+               if (errCode < 0) {
+                       err ("cannot change alternate number to %d (error=%i)",
+                                                       dev->ifaceAlt, errCode);
+                       return errCode;
+               }
+       }
+
+       PDEBUG(DBG_ISOC, "ISO Packet Length:%d", dev->isocPacketSize);
+
+       return 0;
+}
+
 /*
  * usbvision_init_isoc()
  *
        scratch_reset(usbvision);
 
        /* Alternate interface 1 is is the biggest frame size */
-       errCode = usb_set_interface(dev, usbvision->iface, usbvision->ifaceAltActive);
+       errCode = usbvision_set_alternate(usbvision);
        if (errCode < 0) {
                usbvision->last_error = errCode;
                return -EBUSY;
        }
 
        regValue = (16 - usbvision_read_reg(usbvision, USBVISION_ALTER_REG)) & 0x0F;
-       usbvision->isocPacketSize = (regValue == 0) ? 0 : (regValue * 64) - 1;
-       PDEBUG(DBG_ISOC, "ISO Packet Length:%d", usbvision->isocPacketSize);
 
        usbvision->usb_bandwidth = regValue >> 1;
        PDEBUG(DBG_ISOC, "USB Bandwidth Usage: %dMbit/Sec", usbvision->usb_bandwidth);
        if (!usbvision->remove_pending) {
 
                /* Set packet size to 0 */
+               usbvision->ifaceAlt=0;
                errCode = usb_set_interface(usbvision->dev, usbvision->iface,
-                                     usbvision->ifaceAltInactive);
+                                           usbvision->ifaceAlt);
                if (errCode < 0) {
                        err("%s: usb_set_interface() failed: error %d", __FUNCTION__, errCode);
                        usbvision->last_error = errCode;
 
        ctrl.value = 0;
        if(usbvision->user)
                call_i2c_clients(usbvision, VIDIOC_G_CTRL, &ctrl);
-       return sprintf(buf, "%d\n", ctrl.value >> 8);
+       return sprintf(buf, "%d\n", ctrl.value);
 }
 static CLASS_DEVICE_ATTR(hue, S_IRUGO, show_hue, NULL);
 
        ctrl.value = 0;
        if(usbvision->user)
                call_i2c_clients(usbvision, VIDIOC_G_CTRL, &ctrl);
-       return sprintf(buf, "%d\n", ctrl.value >> 8);
+       return sprintf(buf, "%d\n", ctrl.value);
 }
 static CLASS_DEVICE_ATTR(contrast, S_IRUGO, show_contrast, NULL);
 
        ctrl.value = 0;
        if(usbvision->user)
                call_i2c_clients(usbvision, VIDIOC_G_CTRL, &ctrl);
-       return sprintf(buf, "%d\n", ctrl.value >> 8);
+       return sprintf(buf, "%d\n", ctrl.value);
 }
 static CLASS_DEVICE_ATTR(brightness, S_IRUGO, show_brightness, NULL);
 
        ctrl.value = 0;
        if(usbvision->user)
                call_i2c_clients(usbvision, VIDIOC_G_CTRL, &ctrl);
-       return sprintf(buf, "%d\n", ctrl.value >> 8);
+       return sprintf(buf, "%d\n", ctrl.value);
 }
 static CLASS_DEVICE_ATTR(saturation, S_IRUGO, show_saturation, NULL);
 
                case VIDIOC_G_CTRL:
                {
                        struct v4l2_control *ctrl = arg;
-                       PDEBUG(DBG_IOCTL,"VIDIOC_G_CTRL id=%x value=%x",ctrl->id,ctrl->value);
                        call_i2c_clients(usbvision, VIDIOC_G_CTRL, ctrl);
+                       PDEBUG(DBG_IOCTL,"VIDIOC_G_CTRL id=%x value=%x",ctrl->id,ctrl->value);
                        return 0;
                }
                case VIDIOC_S_CTRL:
                        }
                }
 
+               /* Alternate interface 1 is is the biggest frame size */
+               errCode = usbvision_set_alternate(usbvision);
+               if (errCode < 0) {
+                       usbvision->last_error = errCode;
+                       return -EBUSY;
+               }
+
                // If so far no errors then we shall start the radio
                usbvision->radio = 1;
                call_i2c_clients(usbvision,AUDC_SET_RADIO,&usbvision->tuner_type);
 
        down(&usbvision->lock);
 
+       /* Set packet size to 0 */
+       usbvision->ifaceAlt=0;
+       errCode = usb_set_interface(usbvision->dev, usbvision->iface,
+                                   usbvision->ifaceAlt);
+
        usbvision_audio_off(usbvision);
        usbvision->radio=0;
        usbvision->user--;
  */
 static int __devinit usbvision_probe(struct usb_interface *intf, const struct usb_device_id *devid)
 {
-       struct usb_device *dev = interface_to_usbdev(intf);
+       struct usb_device *dev = usb_get_dev(interface_to_usbdev(intf));
+       struct usb_interface *uif;
        __u8 ifnum = intf->altsetting->desc.bInterfaceNumber;
        const struct usb_host_interface *interface;
        struct usb_usbvision *usbvision = NULL;
        const struct usb_endpoint_descriptor *endpoint;
-       int model;
+       int model,i;
 
        PDEBUG(DBG_PROBE, "VID=%#04x, PID=%#04x, ifnum=%u",
                                        dev->descriptor.idVendor, dev->descriptor.idProduct, ifnum);
+
        /* Is it an USBVISION video dev? */
        model = 0;
        for(model = 0; usbvision_device_data[model].idVendor; model++) {
        endpoint = &interface->endpoint[1].desc;
        if ((endpoint->bmAttributes & USB_ENDPOINT_XFERTYPE_MASK) != USB_ENDPOINT_XFER_ISOC) {
                err("%s: interface %d. has non-ISO endpoint!", __FUNCTION__, ifnum);
-               err("%s: Endpoint attribures %d", __FUNCTION__, endpoint->bmAttributes);
+               err("%s: Endpoint attributes %d", __FUNCTION__, endpoint->bmAttributes);
                return -ENODEV;
        }
        if ((endpoint->bEndpointAddress & USB_ENDPOINT_DIR_MASK) == USB_DIR_OUT) {
 
        down(&usbvision->lock);
 
+       /* compute alternate max packet sizes */
+       uif = dev->actconfig->interface[0];
+
+       usbvision->num_alt=uif->num_altsetting;
+       PDEBUG(DBG_PROBE, "Alternate settings: %i",usbvision->num_alt);
+       usbvision->alt_max_pkt_size = kmalloc(32*
+                                             usbvision->num_alt,GFP_KERNEL);
+       if (usbvision->alt_max_pkt_size == NULL) {
+               err("usbvision: out of memory!\n");
+               return -ENOMEM;
+       }
+
+       for (i = 0; i < usbvision->num_alt ; i++) {
+               u16 tmp = le16_to_cpu(uif->altsetting[i].endpoint[1].desc.
+                                     wMaxPacketSize);
+               usbvision->alt_max_pkt_size[i] =
+                       (tmp & 0x07ff) * (((tmp & 0x1800) >> 11) + 1);
+               PDEBUG(DBG_PROBE, "Alternate setting %i, max size= %i",i,
+                      usbvision->alt_max_pkt_size[i]);
+       }
+
+
        usbvision->nr = usbvision_nr++;
 
        usbvision->have_tuner = usbvision_device_data[model].Tuner;
        usbvision->DevModel = model;
        usbvision->remove_pending = 0;
        usbvision->iface = ifnum;
-       usbvision->ifaceAltInactive = 0;
-       usbvision->ifaceAltActive = 1;
+       usbvision->ifaceAlt = 0;
        usbvision->video_endp = endpoint->bEndpointAddress;
        usbvision->isocPacketSize = 0;
        usbvision->usb_bandwidth = 0;