title: Using libusb on Android without rooting
body: <p>I am trying to communicate with USB device from Android-based smartphone via OTG. I was able to communicate with my device using Android USB Host API. The problem of USB Host API solution is performance (single bulk transfer bounded by 16384 bytes). </p>
  
  <p>The libusb can perform larger requests and now I am trying to integrate it using Android NDK. I succeeded to compile libusb sources for Android and even <code>initUSB()</code>, but <code>libusb_open(dev, &amp;dev_handle)</code> returns -3 (Access denied).</p>
  
  <p>How can I pass the file descriptor </p>
  
  <pre><code>int fd = connection.getFileDescriptor()
  </code></pre>
  
  <p>to libusb after getting USB_PERMISSION under Android USB Host API and get USB device access under libusb?</p>