Index: firmware/target/arm/usb-drv-arc.c
===================================================================
--- firmware/target/arm/usb-drv-arc.c	(Revision 30624)
+++ firmware/target/arm/usb-drv-arc.c	(Arbeitskopie)
@@ -428,31 +428,9 @@
     }
 }
 
-#ifdef LOGF_ENABLE
-#define XFER_DIR_STR(dir) ((dir) ? "IN" : "OUT")
-#define XFER_TYPE_STR(type) \
-    ((type) == USB_ENDPOINT_XFER_CONTROL ? "CTRL" : \
-     ((type) == USB_ENDPOINT_XFER_ISOC ? "ISOC" : \
-      ((type) == USB_ENDPOINT_XFER_BULK ? "BULK" : \
-       ((type) == USB_ENDPOINT_XFER_INT ? "INTR" : "INVL"))))
-
-static void log_ep(int ep_num, int ep_dir, char* prefix)
-{
-    usb_endpoint_t* endpoint = &endpoints[ep_num];
-
-    logf("%s: ep%d %s %s %d", prefix, ep_num, XFER_DIR_STR(ep_dir),
-            XFER_TYPE_STR(endpoint->type[ep_dir]),
-            endpoint->max_pkt_size[ep_dir]);
-}
-#else
-#undef log_ep
-#define log_ep(...)
-#endif
-
 /* manual: 32.14.1 Device Controller Initialization */
-void usb_drv_init(void)
+static void _usb_drv_init(bool attach)
 {
-    /* USB core decides */
     usb_drv_reset();
 
     REG_USBMODE = USBMODE_CTRL_MODE_DEVICE;
@@ -469,12 +447,19 @@
     REG_ENDPOINTLISTADDR = (unsigned int)qh_array;
     REG_DEVICEADDR = 0;
 
-    /* enable USB interrupts */
-    REG_USBINTR =
-        USBINTR_INT_EN |
-        USBINTR_ERR_INT_EN |
-        USBINTR_PTC_DETECT_EN |
-        USBINTR_RESET_EN;
+    if (!attach) {
+        /* enable RESET interrupt */
+        REG_USBINTR = USBINTR_RESET_EN;
+    }
+    else
+    {
+        /* enable USB interrupts */
+        REG_USBINTR =
+            USBINTR_INT_EN |
+            USBINTR_ERR_INT_EN |
+            USBINTR_PTC_DETECT_EN |
+            USBINTR_RESET_EN;
+    }
 
     usb_drv_int_enable(true);
 
@@ -487,12 +472,49 @@
     logf("usb dccparams %x", REG_DCCPARAMS);
 
     /* now a bus reset will occur. see bus_reset() */
+    (void)attach;
 }
 
+#ifdef LOGF_ENABLE
+#define XFER_DIR_STR(dir) ((dir) ? "IN" : "OUT")
+#define XFER_TYPE_STR(type) \
+    ((type) == USB_ENDPOINT_XFER_CONTROL ? "CTRL" : \
+     ((type) == USB_ENDPOINT_XFER_ISOC ? "ISOC" : \
+      ((type) == USB_ENDPOINT_XFER_BULK ? "BULK" : \
+       ((type) == USB_ENDPOINT_XFER_INT ? "INTR" : "INVL"))))
+
+static void log_ep(int ep_num, int ep_dir, char* prefix)
+{
+    usb_endpoint_t* endpoint = &endpoints[ep_num];
+
+    logf("%s: ep%d %s %s %d", prefix, ep_num, XFER_DIR_STR(ep_dir),
+            XFER_TYPE_STR(endpoint->type[ep_dir]),
+            endpoint->max_pkt_size[ep_dir]);
+}
+#else
+#undef log_ep
+#define log_ep(...)
+#endif
+
+void usb_drv_init(void)
+{
+#if 0//def USB_DETECT_BY_CORE
+    /* USB core decides */
+    _usb_drv_init(true);
+#else
+    /* Use bus reset condition */
+    _usb_drv_init(false);
+#endif
+}
+
 /* fully enable driver */
 void usb_drv_attach(void)
 {
     logf("usb_drv_attach");
+#if 1//ndef USB_DETECT_BY_CORE
+    sleep(HZ/10);
+    _usb_drv_init(true);
+#endif
 }
 
 void usb_drv_exit(void)
@@ -541,8 +563,17 @@
     /* reset interrupt */
     if (status & USBSTS_RESET) {
         REG_USBSTS = USBSTS_RESET;
-        bus_reset();
-        usb_core_bus_reset(); /* tell mom */
+
+        if (UNLIKELY(usbintr == USBINTR_RESET_EN)) {
+            /* USB detected - detach and inform */
+            usb_drv_stop();
+            usb_drv_usb_detect_event();
+        }
+        else
+        {
+            bus_reset();
+            usb_core_bus_reset(); /* tell mom */
+        }
     }
 
     /* port change */