usb: dwc3: gadget: move requests to cancelled_list

commit d4f1afe5 upstream

Whenever we have a request in flight, we can move it to the cancelled
list and later simply iterate over that list and skip over any TRBs we
find.

Cc: Fei Yang <fei.yang@intel.com>
Cc: Sam Protsenko <semen.protsenko@linaro.org>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: linux-usb@vger.kernel.org
Cc: stable@vger.kernel.org # 4.19.y
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
(cherry picked from commit d4f1afe5)
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/usb/dwc3/gadget.c

@@ -1364,6 +1364,17 @@ static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct dwc3_request *r
 	}
 }
 
+static void dwc3_gadget_ep_cleanup_cancelled_requests(struct dwc3_ep *dep)
+{
+	struct dwc3_request		*req;
+	struct dwc3_request		*tmp;
+
+	list_for_each_entry_safe(req, tmp, &dep->cancelled_list, list) {
+		dwc3_gadget_ep_skip_trbs(dep, req);
+		dwc3_gadget_giveback(dep, req, -ECONNRESET);
+	}
+}
+
 static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 		struct usb_request *request)
 {
@@ -1400,8 +1411,9 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 			if (!r->trb)
 				goto out0;
 
-			dwc3_gadget_ep_skip_trbs(dep, r);
-			goto out1;
+			dwc3_gadget_move_cancelled_request(req);
+			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+			goto out0;
 		}
 		dev_err(dwc->dev, "request %pK was not queued to %s\n",
 				request, ep->name);
@@ -1409,7 +1421,6 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 		goto out0;
 	}
 
-out1:
 	dwc3_gadget_giveback(dep, req, -ECONNRESET);
 
 out0: