usb: dwc3: debug: decode control endpoint phase too

DWC3 can tell us which phase of a setup transfer
we're getting into. Let's decode it from the event
to make it easier to debug.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/dwc3/core.h

@@ -1041,6 +1041,7 @@ struct dwc3_event_depevt {
 /* Control-only Status */
 #define DEPEVT_STATUS_CONTROL_DATA	1
 #define DEPEVT_STATUS_CONTROL_STATUS	2
+#define DEPEVT_STATUS_CONTROL_PHASE(n)	((n) & 3)
 
 /* In response to Start Transfer */
 #define DEPEVT_TRANSFER_NO_RESOURCE	1

drivers/usb/dwc3/debug.h

@@ -207,6 +207,19 @@ dwc3_ep_event_string(const struct dwc3_event_depevt *event)
 		strcat(str, "Transfer Not Ready");
 		status = event->status & DEPEVT_STATUS_TRANSFER_ACTIVE;
 		strcat(str, status ? " (Active)" : " (Not Active)");
+
+		/* Control Endpoints */
+		if (epnum <= 1) {
+			int phase = DEPEVT_STATUS_CONTROL_PHASE(event->status);
+
+			switch (phase) {
+			case DEPEVT_STATUS_CONTROL_DATA:
+				strcat(str, " [Data Phase]");
+				break;
+			case DEPEVT_STATUS_CONTROL_STATUS:
+				strcat(str, " [Status Phase]");
+			}
+		}
 		break;
 	case DWC3_DEPEVT_RXTXFIFOEVT:
 		strcat(str, "FIFO");