Set USBHS_USBCMD_ITC to 1, workaround for race condition in some drivers

USBHost_t36.h

@@ -62,6 +62,15 @@
 //#define USBHOST_PRINT_DEBUG
 
 
+// When developing a new driver, please edit ehci.cpp to set
+// USBHS_USBCMD_ITC to zero.  Today we set USBHS_USBCMD_ITC(1)
+// because some drivers have race conditions exposed by
+// non-delayed interrupts.  Eventually USBHS_USBCMD_ITC will
+// be changed to 0.  Please test any new driver code with
+// USBHS_USBCMD_ITC(0) so it won't break in the future when
+// this change is made!
+
+
 // This can let you control where to send the debugging messages
 //#define USBHDBGSerial	Serial1
 #ifndef USBHDBGSerial

ehci.cpp

@@ -239,7 +239,7 @@ void USBHost::begin()
 	USBHS_PERIODICLISTBASE = (uint32_t)periodictable;
 	USBHS_FRINDEX = 0;
 	USBHS_ASYNCLISTADDR = 0;
-	USBHS_USBCMD = USBHS_USBCMD_ITC(0) | USBHS_USBCMD_RS |
+	USBHS_USBCMD = USBHS_USBCMD_ITC(1) | USBHS_USBCMD_RS |
 		USBHS_USBCMD_ASP(3) | USBHS_USBCMD_ASPE | USBHS_USBCMD_PSE |
 		#if PERIODIC_LIST_SIZE == 8
 		USBHS_USBCMD_FS2 | USBHS_USBCMD_FS(3);