- intf = usb_ifnum_to_if(gspca_dev->dev, gspca_dev->iface);
- ep = NULL;
- xfer = gspca_dev->cam.bulk ? USB_ENDPOINT_XFER_BULK
- : USB_ENDPOINT_XFER_ISOC;
- i = gspca_dev->alt; /* previous alt setting */
- if (gspca_dev->cam.reverse_alts) {
- while (++i < gspca_dev->nbalt) {
- ep = alt_xfer(&intf->altsetting[i], xfer);
- if (ep)
- break;
- }
- } else {
- while (--i >= 0) {
- ep = alt_xfer(&intf->altsetting[i], xfer);
- if (ep)
- break;
- }
- }
- if (ep == NULL) {
- err("no transfer endpoint found");
- return NULL;
- }
- PDEBUG(D_STREAM, "use alt %d ep 0x%02x",
- i, ep->desc.bEndpointAddress);
- gspca_dev->alt = i; /* memorize the current alt setting */
- if (gspca_dev->nbalt > 1) {
- ret = usb_set_interface(gspca_dev->dev, gspca_dev->iface, i);
- if (ret < 0) {
- err("set alt %d err %d", i, ret);
- ep = NULL;
+ nbalt = intf->num_altsetting;
+ if (nbalt > MAX_ALT)
+ nbalt = MAX_ALT; /* fixme: should warn */
+
+ /* build the endpoint table */
+ i = 0;
+ last_bw = 0;
+ for (;;) {
+ ep_tb->bandwidth = 2000 * 2000 * 120;
+ found = 0;
+ for (j = 0; j < nbalt; j++) {
+ ep = alt_xfer(&intf->altsetting[j], xfer);
+ if (ep == NULL)
+ continue;
+ psize = le16_to_cpu(ep->desc.wMaxPacketSize);
+ if (!gspca_dev->cam.bulk) /* isoc */
+ psize = (psize & 0x07ff) *
+ (1 + ((psize >> 11) & 3));
+ bandwidth = psize * ep->desc.bInterval * 1000;
+ if (gspca_dev->dev->speed == USB_SPEED_HIGH
+ || gspca_dev->dev->speed == USB_SPEED_SUPER)
+ bandwidth *= 8;
+ if (bandwidth <= last_bw)
+ continue;
+ if (bandwidth < ep_tb->bandwidth) {
+ ep_tb->bandwidth = bandwidth;
+ ep_tb->alt = j;
+ found = 1;
+ }