usb: dwc3: gadget: Properly handle ClearFeature(halt)

DWC3 must not issue CLEAR_STALL command to control endpoints. The
controller automatically clears the STALL when it receives the SETUP
token. Also, when the driver receives ClearFeature(halt_ep), DWC3 must
stop any active transfer from the endpoint and give back all the
requests to the function drivers.

Fixes: 72246da40f ("usb: Introduce DesignWare USB3 DRD Driver")
Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc3/gadget.c

@@ -1508,6 +1508,10 @@ static void dwc3_gadget_ep_skip_trbs(struct dwc3_ep *dep, struct dwc3_request *r
 {
 	int i;
 
+	/* If req->trb is not set, then the request has not started */
+	if (!req->trb)
+		return;
+
 	/*
 	 * If request was already started, this means we had to
 	 * stop the transfer. With that we also need to ignore
@@ -1598,6 +1602,8 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
 {
 	struct dwc3_gadget_ep_cmd_params	params;
 	struct dwc3				*dwc = dep->dwc;
+	struct dwc3_request			*req;
+	struct dwc3_request			*tmp;
 	int					ret;
 
 	if (usb_endpoint_xfer_isoc(dep->endpoint.desc)) {
@@ -1634,13 +1640,37 @@ int __dwc3_gadget_ep_set_halt(struct dwc3_ep *dep, int value, int protocol)
 		else
 			dep->flags |= DWC3_EP_STALL;
 	} else {
+		/*
+		 * Don't issue CLEAR_STALL command to control endpoints. The
+		 * controller automatically clears the STALL when it receives
+		 * the SETUP token.
+		 */
+		if (dep->number <= 1) {
+			dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
+			return 0;
+		}
 
 		ret = dwc3_send_clear_stall_ep_cmd(dep);
-		if (ret)
+		if (ret) {
 			dev_err(dwc->dev, "failed to clear STALL on %s\n",
 					dep->name);
-		else
+			return ret;
-			dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
+		}
+
+		dep->flags &= ~(DWC3_EP_STALL | DWC3_EP_WEDGE);
+
+		dwc3_stop_active_transfer(dep, true, true);
+
+		list_for_each_entry_safe(req, tmp, &dep->started_list, list)
+			dwc3_gadget_move_cancelled_request(req);
+
+		list_for_each_entry_safe(req, tmp, &dep->pending_list, list)
+			dwc3_gadget_move_cancelled_request(req);
+
+		if (!(dep->flags & DWC3_EP_END_TRANSFER_PENDING)) {
+			dep->flags &= ~DWC3_EP_DELAY_START;
+			dwc3_gadget_ep_cleanup_cancelled_requests(dep);
+		}
 	}
 
 	return ret;