Prevent USB commands from working when USB is stopped.

CHANGELOG

@@ -2,6 +2,8 @@
 Changes since U-Boot 1.1.4:
 ======================================================================
 
+* Prevent USB commands from working when USB is stopped.
+
 * Add rudimentary handling of alternate settings of USB interfaces.
   This is in order to fix issues with some USB sticks or knives timing
   out during initialisation. Some code readability improvements.

common/cmd_usb.c

@@ -444,6 +444,7 @@ int do_usb (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 
 	int i;
 	struct usb_device *dev = NULL;
+	extern char usb_started;
 #ifdef CONFIG_USB_STORAGE
 	block_dev_desc_t *stor_dev;
 #endif
@@ -477,6 +478,10 @@ int do_usb (cmd_tbl_t *cmdtp, int flag, int argc, char *argv[])
 		usb_stop();
 		return 0;
 	}
+	if (!usb_started) {
+		printf("USB is stopped. Please issue 'usb start' first.\n");
+		return 1;
+	}
 	if (strncmp(argv[1],"tree",4) == 0) {
 		printf("\nDevice Tree:\n");
 		usb_show_tree(usb_get_dev_index(0));

common/usb.c

@@ -72,6 +72,8 @@ static int running;
 static int asynch_allowed;
 static struct devrequest setup_packet;
 
+char usb_started; /* flag for the started/stopped USB status */
+
 /**********************************************************************
  * some forward declerations...
  */
@@ -110,10 +112,12 @@ int usb_init(void)
 		printf("scanning bus for devices... ");
 		running=1;
 		usb_scan_devices();
+		usb_started = 1;
 		return 0;
 	}
 	else {
 		printf("Error, couldn't init Lowlevel part\n");
+		usb_started = 0;
 		return -1;
 	}
 }
@@ -124,6 +128,7 @@ int usb_init(void)
 int usb_stop(void)
 {
 	asynch_allowed=1;
+	usb_started = 0;
 	usb_hub_reset();
 	return usb_lowlevel_stop();
 }