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);
+}
+