Treat dr_mode of USB_DR_MODE_UNKNOWN as USB_DR_MODE_OTG to
enhance functional robustness.
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
                return PTR_ERR(ssusb->ippc_base);
 
        ssusb->dr_mode = usb_get_dr_mode(dev);
-       if (ssusb->dr_mode == USB_DR_MODE_UNKNOWN) {
-               dev_err(dev, "dr_mode is error\n");
-               return -EINVAL;
-       }
+       if (ssusb->dr_mode == USB_DR_MODE_UNKNOWN)
+               ssusb->dr_mode = USB_DR_MODE_OTG;
 
        if (ssusb->dr_mode == USB_DR_MODE_PERIPHERAL)
                return 0;