FAILED: patch "[PATCH] usb: dwc3: gadget: always unmap EP0 requests" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From: Felipe Balbi <[email protected]>
Date: Tue, 20 Dec 2016 14:14:40 +0200
Subject: [PATCH] usb: dwc3: gadget: always unmap EP0 requests

commit 0416e494ce7d ("usb: dwc3: ep0: correct cache sync issue in case of ep0_bounced") introduced a bug where we would leak DMA resources which would cause us to starve the system of them resulting in failing DMA transfers.

Fix the bug by making sure that we always unmap EP0 requests since those are *always* mapped.

sync issue in case of ep0_bounced")

index efddaf5d11d1..0286e3141864 100644
@@ -180,11 +180,11 @@ void dwc3_gadget_giveback(struct dwc3_ep *dep, struct dwc3_request *req,
 	if (req->request.status == -EINPROGRESS)
 		req->request.status = status;
 
-	if (dwc->ep0_bounced && dep->number == 0)
+	if (dwc->ep0_bounced && dep->number <= 1)
 		dwc->ep0_bounced = false;
-	else
-		usb_gadget_unmap_request_by_dev(dwc->sysdev,
-				&req->request, req->direction);
+
+	usb_gadget_unmap_request_by_dev(dwc->sysdev,
+			&req->request, req->direction);
 
 	trace_dwc3_gadget_giveback(req);