Suppress attempts to manage USB trace if the USB MSC example is built as an NSH built-in application. In that case, USB MSC does not do a good job managing trace data and gets in the way of other things that can do a better job (like NSH or the USB monitor).

ChangeLog.txt

@@ -628,4 +628,8 @@
 	* apps/examples/pwm:  Clean-up some configuration confusion (2013-9-5).
 	* apps/netutils/dhcpd/dhcpd.c:  Fix calculation of the next lease
 	  address.  SourceForge bug #21 from Paolo Messina (2013-9-6).
+	* apps/examples/usbmsc:  Don't try to control USB trace if we are
+	  an NSH built-in task.  In that case our attempts are inadequate
+	  and only interfere with with other logic that is attempting to
+	  to do the same thing (in NSH or in the USB monitor) (2013-9-6).
 

examples/usbmsc/Kconfig

@@ -70,10 +70,20 @@ config EXAMPLES_USBMSC_DEBUGMM
 	---help---
 		Enables some debug tests to check for memory usage and memory leaks.
 
+config EXAMPLES_USBMSC_TRACE
+	bool "Trace USB activity"
+	default n
+	depends on (USBDEV_TRACE || DEBUG_USB) && !NSH_BUILTIN_APPS
+	---help---
+		If this example is built as a standalone task and if USB device tracing is
+		enabled, then this example can be configured to unobtrusively monitor
+		USB activity by selecting this option.
+
+if EXAMPLES_USBMSC_TRACE
+
 config EXAMPLES_USBMSC_TRACEINIT
 	bool "USB Trace Initialization"
 	default n
-	depends on USBDEV_TRACE || DEBUG_USB
 	---help---
 		If USBDEV_TRACE is enabled (or DEBUG and DEBUG_USB),
 		then the example code will also manage the USB trace output.  The
@@ -83,7 +93,6 @@ config EXAMPLES_USBMSC_TRACEINIT
 config EXAMPLES_USBMSC_TRACECLASS
 	bool "USB Trace Class"
 	default n
-	depends on USBDEV_TRACE || DEBUG_USB
 	---help---
 		If USBDEV_TRACE is enabled (or DEBUG and DEBUG_USB),
 		then the example code will also manage the USB trace output.  The
@@ -93,7 +102,6 @@ config EXAMPLES_USBMSC_TRACECLASS
 config EXAMPLES_USBMSC_TRACETRANSFERS
 	bool "USB Trace Transfers"
 	default n
-	depends on USBDEV_TRACE || DEBUG_USB
 	---help---
 		If USBDEV_TRACE is enabled (or DEBUG and DEBUG_USB),
 		then the example code will also manage the USB trace output.  The
@@ -103,7 +111,6 @@ config EXAMPLES_USBMSC_TRACETRANSFERS
 config EXAMPLES_USBMSC_TRACECONTROLLER
 	bool "USB Trace Device Controller Events"
 	default n
-	depends on USBDEV_TRACE || DEBUG_USB
 	---help---
 		If USBDEV_TRACE is enabled (or DEBUG and DEBUG_USB),
 		then the example code will also manage the USB trace output.  The
@@ -113,12 +120,12 @@ config EXAMPLES_USBMSC_TRACECONTROLLER
 config EXAMPLES_USBMSC_TRACEINTERRUPTS
 	bool "USB Trace Device Controller Interrupt Events"
 	default n
-	depends on USBDEV_TRACE || DEBUG_USB
 	---help---
 		If USBDEV_TRACE is enabled (or DEBUG and DEBUG_USB),
 		then the example code will also manage the USB trace output.  The
 		amount of trace output can be controlled this configuration value:
 		This setting will show USB device controller interrupt-related events.
 
-endif
+endif # EXAMPLES_USBMSC_TRACE
+endif # EXAMPLES_USBMSC
 

examples/usbmsc/usbmsc_main.c

@@ -196,7 +196,7 @@ static void final_memory_usage(FAR const char *msg)
  * Name: usbmsc_enumerate
  ****************************************************************************/
 
-#ifdef CONFIG_USBDEV_TRACE
+#ifdef CONFIG_EXAMPLES_USBMSC_TRACE
 static int usbmsc_enumerate(struct usbtrace_s *trace, void *arg)
 {
   switch (trace->event)
@@ -423,8 +423,10 @@ int msconn_main(int argc, char *argv[])
 
   /* Initialize USB trace output IDs */
 
+#ifdef CONFIG_EXAMPLES_USBMSC_TRACE
   usbtrace_enable(TRACE_BITSET);
   check_test_memory_usage("After usbtrace_enable()");
+#endif
 
   /* Register block drivers (architecture-specific) */
 
@@ -513,9 +515,9 @@ int msconn_main(int argc, char *argv[])
       msgflush();
       sleep(5);
 
-#  ifdef CONFIG_USBDEV_TRACE
+#  ifdef CONFIG_EXAMPLES_USBMSC_TRACE
       message("\nmsconn_main: USB TRACE DATA:\n");
-      ret =  usbtrace_enumerate(usbmsc_enumerate, NULL);
+      ret = usbtrace_enumerate(usbmsc_enumerate, NULL);
       if (ret < 0)
         {
           message("msconn_main: usbtrace_enumerate failed: %d\n", -ret);