1 files changed, 19 insertions, 1 deletions
diff --git a/hw/usb.c b/hw/usb.c
index 39d29f3daf..2eda86a58c 100644
--- a/hw/usb.c
+++ b/hw/usb.c
@@ -28,7 +28,25 @@
 
 void usb_attach(USBPort *port, USBDevice *dev)
 {
-    port->ops->attach(port, dev);
+    if (dev != NULL) {
+        /* attach */
+        if (port->dev) {
+            usb_attach(port, NULL);
+        }
+        dev->port = port;
+        port->dev = dev;
+        port->ops->attach(port);
+        usb_send_msg(dev, USB_MSG_ATTACH);
+    } else {
+        /* detach */
+        dev = port->dev;
+        port->ops->detach(port);
+        if (dev) {
+            usb_send_msg(dev, USB_MSG_DETACH);
+            dev->port = NULL;
+            port->dev = NULL;
+        }
+    }
 }
 
 /**********************/