usb: dwc3: handle pending unaligned Control OUT data phase correctly

When DWC3_EP_PENDING_REQUEST flag is set for a Control OUT Data
phase transfer, we would be missing the proper handling for
unaligned OUT requests, thus hanging a transfer.

Since proper handling is already done on dwc3_ep0_do_control_data(),
we simply re-factor that function so it can be re-used from
__dwc3_gadget_ep0_queue().

Reported-by: Pratyush Anand <pratyush.anand@st.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

drivers/usb/dwc3/ep0.c

@@ -55,6 +55,8 @@
 #include "io.h"
 
 static void dwc3_ep0_do_control_status(struct dwc3 *dwc, u32 epnum);
+static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
+		struct dwc3_ep *dep, struct dwc3_request *req);
 
 static const char *dwc3_ep0_state_string(enum dwc3_ep0_state state)
 {
@@ -150,9 +152,8 @@ static int __dwc3_gadget_ep0_queue(struct dwc3_ep *dep,
 			return 0;
 		}
 
-		ret = dwc3_ep0_start_trans(dwc, direction,
-				req->request.dma, req->request.length,
-				DWC3_TRBCTL_CONTROL_DATA);
+		__dwc3_ep0_do_control_data(dwc, dwc->eps[direction], req);
+
 		dep->flags &= ~(DWC3_EP_PENDING_REQUEST |
 				DWC3_EP0_DIR_IN);
 	} else if (dwc->delayed_status) {
@@ -787,68 +788,81 @@ static void dwc3_ep0_do_control_setup(struct dwc3 *dwc,
 	dwc3_ep0_out_start(dwc);
 }
 
-static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
-		const struct dwc3_event_depevt *event)
+static void __dwc3_ep0_do_control_data(struct dwc3 *dwc,
+		struct dwc3_ep *dep, struct dwc3_request *req)
 {
-	struct dwc3_ep		*dep;
-	struct dwc3_request	*req;
 	int			ret;
 
-	dep = dwc->eps[0];
-
-	if (list_empty(&dep->request_list)) {
-		dev_vdbg(dwc->dev, "pending request for EP0 Data phase\n");
-		dep->flags |= DWC3_EP_PENDING_REQUEST;
-
-		if (event->endpoint_number)
-			dep->flags |= DWC3_EP0_DIR_IN;
-		return;
-	}
-
-	req = next_request(&dep->request_list);
-	req->direction = !!event->endpoint_number;
+	req->direction = !!dep->number;
 
 	if (req->request.length == 0) {
-		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
+		ret = dwc3_ep0_start_trans(dwc, dep->number,
 				dwc->ctrl_req_addr, 0,
 				DWC3_TRBCTL_CONTROL_DATA);
 	} else if ((req->request.length % dep->endpoint.maxpacket)
-			&& (event->endpoint_number == 0)) {
+			&& (dep->number == 0)) {
+		u32		transfer_size;
+
 		ret = usb_gadget_map_request(&dwc->gadget, &req->request,
-				event->endpoint_number);
+				dep->number);
 		if (ret) {
 			dev_dbg(dwc->dev, "failed to map request\n");
 			return;
 		}
 
 		WARN_ON(req->request.length > DWC3_EP0_BOUNCE_SIZE);
 
+		transfer_size = roundup(req->request.length,
+				(u32) dep->endpoint.maxpacket);
+
 		dwc->ep0_bounced = true;
 
 		/*
 		 * REVISIT in case request length is bigger than
 		 * DWC3_EP0_BOUNCE_SIZE we will need two chained
 		 * TRBs to handle the transfer.
 		 */
-		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
-				dwc->ep0_bounce_addr, dep->endpoint.maxpacket,
+		ret = dwc3_ep0_start_trans(dwc, dep->number,
+				dwc->ep0_bounce_addr, transfer_size,
 				DWC3_TRBCTL_CONTROL_DATA);
 	} else {
 		ret = usb_gadget_map_request(&dwc->gadget, &req->request,
-				event->endpoint_number);
+				dep->number);
 		if (ret) {
 			dev_dbg(dwc->dev, "failed to map request\n");
 			return;
 		}
 
-		ret = dwc3_ep0_start_trans(dwc, event->endpoint_number,
-				req->request.dma, req->request.length,
-				DWC3_TRBCTL_CONTROL_DATA);
+		ret = dwc3_ep0_start_trans(dwc, dep->number, req->request.dma,
+				req->request.length, DWC3_TRBCTL_CONTROL_DATA);
 	}
 
 	WARN_ON(ret < 0);
 }
 
+static void dwc3_ep0_do_control_data(struct dwc3 *dwc,
+		const struct dwc3_event_depevt *event)
+{
+	struct dwc3_ep		*dep;
+	struct dwc3_request	*req;
+
+	dep = dwc->eps[0];
+
+	if (list_empty(&dep->request_list)) {
+		dev_vdbg(dwc->dev, "pending request for EP0 Data phase\n");
+		dep->flags |= DWC3_EP_PENDING_REQUEST;
+
+		if (event->endpoint_number)
+			dep->flags |= DWC3_EP0_DIR_IN;
+		return;
+	}
+
+	req = next_request(&dep->request_list);
+	dep = dwc->eps[event->endpoint_number];
+
+	__dwc3_ep0_do_control_data(dwc, dep, req);
+}
+
 static int dwc3_ep0_start_control_status(struct dwc3_ep *dep)
 {
 	struct dwc3		*dwc = dep->dwc;