Fix hang part 2...

I am not sure if you can also get the same hang in the periodic update list as well, but to be on the safe side added same checks as the one that was hanging.

ehci.cpp

@@ -1254,16 +1254,6 @@ void USBHost::delete_Pipe(Pipe_t *pipe)
 		// find & free all the transfers which completed
 		println("  Free transfers");
 		Transfer_t *t = async_followup_first;
-#if 0
-		if (t) {
-			println("  (Look at QH list first)");
-			Transfer_t *tr = (Transfer_t *)(pipe->qh.next);
-			while ((uint32_t)tr & 0xFFFFFFE0) {
-				println("    $ ", (uint32_t)tr);
-				tr  = (Transfer_t *)(tr->qtd.next);
-			}
-		}
-#endif		
 		while (t) {
 			print("    * ", (uint32_t)t);
 			Transfer_t *next = t->next_followup;
@@ -1312,12 +1302,28 @@ void USBHost::delete_Pipe(Pipe_t *pipe)
 		// TODO: subtract bandwidth from uframe_bandwidth array
 
 		// find & free all the transfers which completed
+		println("  Free transfers");
 		Transfer_t *t = periodic_followup_first;
 		while (t) {
+			print("    * ", (uint32_t)t);
 			Transfer_t *next = t->next_followup;
 			if (t->pipe == pipe) {
+				print(" * remove");
 				remove_from_periodic_followup_list(t);
-				free_Transfer(t);
+
+				// Only free if not in QH list
+				Transfer_t *tr = (Transfer_t *)(pipe->qh.next);
+				while (((uint32_t)tr & 0xFFFFFFE0) && (tr != t)){
+					tr  = (Transfer_t *)(tr->qtd.next);
+				}
+				if (tr == t) {
+					println(" * defer free until QH");
+				} else {
+					println(" * free");
+					free_Transfer(t);  // The later code should actually free it...
+				}
+			} else {
+				println("");
 			}
 			t = next;
 		}