greybus: es2: add more structure to probe error handling

Add more structure to probe error handling rather than use the big
hammer and call disconnect directly.

This is needed to fix some host-device life-time issues.

Note that there was never any need to clear the USB interface data as
this will be done by driver core.
Signed-off-by: Johan Hovold <johan@hovoldconsulting.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/es2.c

@@ -547,21 +547,13 @@ static int check_urb_status(struct urb *urb)
 	return -EAGAIN;
 }
 
-static void ap_disconnect(struct usb_interface *interface)
+static void es2_destroy(struct es2_ap_dev *es2)
 {
-	struct es2_ap_dev *es2;
 	struct usb_device *udev;
 	int *cport_to_ep;
 	int bulk_in;
 	int i;
 
-	es2 = usb_get_intfdata(interface);
-	if (!es2)
-		return;
-
-	for (i = 0; i < NUM_BULKS; ++i)
-		es2_cport_in_disable(es2, &es2->cport_in[i]);
-
 	debugfs_remove(es2->apb_log_enable_dentry);
 	usb_log_disable(es2);
 
@@ -591,7 +583,6 @@ static void ap_disconnect(struct usb_interface *interface)
 		}
 	}
 
-	usb_set_intfdata(interface, NULL);
 	udev = es2->usb_dev;
 	cport_to_ep = es2->cport_to_ep;
 	gb_hd_remove(es2->hd);
@@ -600,6 +591,17 @@ static void ap_disconnect(struct usb_interface *interface)
 	usb_put_dev(udev);
 }
 
+static void ap_disconnect(struct usb_interface *interface)
+{
+	struct es2_ap_dev *es2 = usb_get_intfdata(interface);
+	int i;
+
+	for (i = 0; i < NUM_BULKS; ++i)
+		es2_cport_in_disable(es2, &es2->cport_in[i]);
+
+	es2_destroy(es2);
+}
+
 static void cport_in_callback(struct urb *urb)
 {
 	struct gb_host_device *hd = urb->context;
@@ -943,12 +945,16 @@ static int ap_probe(struct usb_interface *interface,
 	for (i = 0; i < NUM_BULKS; ++i) {
 		retval = es2_cport_in_enable(es2, &es2->cport_in[i]);
 		if (retval)
-			goto error;
+			goto err_disable_cport_in;
 	}
 
 	return 0;
+
+err_disable_cport_in:
+	for (--i; i >= 0; --i)
+		es2_cport_in_disable(es2, &es2->cport_in[i]);
 error:
-	ap_disconnect(interface);
+	es2_destroy(es2);
 
 	return retval;
 }