1 files changed, 61 insertions, 1 deletions

diff --git a/drivers/usb/gadget/composite.c b/drivers/usb/gadget/composite.c
index 82314ed22506..5cbb1a41c223 100644
--- a/drivers/usb/gadget/composite.c
+++ b/drivers/usb/gadget/composite.c
@@ -461,12 +461,23 @@ static int set_config(struct usb_composite_dev *cdev,
 			reset_config(cdev);
 			goto done;
 		}
+
+		if (result == USB_GADGET_DELAYED_STATUS) {
+			DBG(cdev,
+			 "%s: interface %d (%s) requested delayed status\n",
+					__func__, tmp, f->name);
+			cdev->delayed_status++;
+			DBG(cdev, "delayed_status count %d\n",
+					cdev->delayed_status);
+		}
 	}
 
 	/* when we return, be sure our power usage is valid */
 	power = c->bMaxPower ? (2 * c->bMaxPower) : CONFIG_USB_GADGET_VBUS_DRAW;
 done:
 	usb_gadget_vbus_draw(gadget, power);
+	if (result >= 0 && cdev->delayed_status)
+		result = USB_GADGET_DELAYED_STATUS;
 	return result;
 }
 
@@ -895,6 +906,14 @@ composite_setup(struct usb_gadget *gadget, const struct usb_ctrlrequest *ctrl)
 		if (w_value && !f->set_alt)
 			break;
 		value = f->set_alt(f, w_index, w_value);
+		if (value == USB_GADGET_DELAYED_STATUS) {
+			DBG(cdev,
+			 "%s: interface %d (%s) requested delayed status\n",
+					__func__, intf, f->name);
+			cdev->delayed_status++;
+			DBG(cdev, "delayed_status count %d\n",
+					cdev->delayed_status);
+		}
 		break;
 	case USB_REQ_GET_INTERFACE:
 		if (ctrl->bRequestType != (USB_DIR_IN|USB_RECIP_INTERFACE))
@@ -958,7 +977,7 @@ unknown:
 	}
 
 	/* respond with data transfer before status phase? */
-	if (value >= 0) {
+	if (value >= 0 && value != USB_GADGET_DELAYED_STATUS) {
 		req->length = value;
 		req->zero = value < w_length;
 		value = usb_ep_queue(gadget->ep0, req, GFP_ATOMIC);
@@ -967,6 +986,10 @@ unknown:
 			req->status = 0;
 			composite_setup_complete(gadget->ep0, req);
 		}
+	} else if (value == USB_GADGET_DELAYED_STATUS && w_length != 0) {
+		WARN(cdev,
+			"%s: Delayed status not supported for w_length != 0",
+			__func__);
 	}
 
 done:
@@ -1289,3 +1312,40 @@ void usb_composite_unregister(struct usb_composite_driver *driver)
 		return;
 	usb_gadget_unregister_driver(&composite_driver);
 }
+
+/**
+ * usb_composite_setup_continue() - Continue with the control transfer
+ * @cdev: the composite device who's control transfer was kept waiting
+ *
+ * This function must be called by the USB function driver to continue
+ * with the control transfer's data/status stage in case it had requested to
+ * delay the data/status stages. A USB function's setup handler (e.g. set_alt())
+ * can request the composite framework to delay the setup request's data/status
+ * stages by returning USB_GADGET_DELAYED_STATUS.
+ */
+void usb_composite_setup_continue(struct usb_composite_dev *cdev)
+{
+	int			value;
+	struct usb_request	*req = cdev->req;
+	unsigned long		flags;
+
+	DBG(cdev, "%s\n", __func__);
+	spin_lock_irqsave(&cdev->lock, flags);
+
+	if (cdev->delayed_status == 0) {
+		WARN(cdev, "%s: Unexpected call\n", __func__);
+
+	} else if (--cdev->delayed_status == 0) {
+		DBG(cdev, "%s: Completing delayed status\n", __func__);
+		req->length = 0;
+		value = usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC);
+		if (value < 0) {
+			DBG(cdev, "ep_queue --> %d\n", value);
+			req->status = 0;
+			composite_setup_complete(cdev->gadget->ep0, req);
+		}
+	}
+
+	spin_unlock_irqrestore(&cdev->lock, flags);
+}
+