title: how is different between controlTransfer and bulkTransfer?
body: <p>I'm making an Android application getting data from a USB device (mode USB host). I read the document at <a href="https://developer.android.com/index.html" rel="nofollow noreferrer">https://developer.android.com/index.html</a> and also some posts in <code>stackoverflow</code> and I found that they use sometimes <code>bulkTransfer()</code>, sometimes <code>controlTransfer()</code> but I can't find out the difference between two method and when do we use each one? Could anyone please give me some suggestion?</p>