usb: dwc3: gadget: use num_trbs when skipping TRBs on ->dequeue()

commit c3acd590 upstream

Now that we track how many TRBs a request uses, it's easier to skip
over them in case of a call to usb_ep_dequeue(). Let's do so and
simplify the code a bit.

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 c3acd590)
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/usb/dwc3/gadget.c

@@ -1368,6 +1368,8 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 				break;
 		}
 		if (r == req) {
+			int i;
+
 			/* wait until it is processed */
 			dwc3_stop_active_transfer(dep, true);
 
@@ -1405,32 +1407,12 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 			if (!r->trb)
 				goto out0;
 
-			if (r->num_pending_sgs) {
+			for (i = 0; i < r->num_trbs; i++) {
 				struct dwc3_trb *trb;
-				int i = 0;
-
-				for (i = 0; i < r->num_pending_sgs; i++) {
-					trb = r->trb + i;
-					trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
-					dwc3_ep_inc_deq(dep);
-				}
-
-				if (r->needs_extra_trb) {
-					trb = r->trb + r->num_pending_sgs + 1;
-					trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
-					dwc3_ep_inc_deq(dep);
-				}
-			} else {
-				struct dwc3_trb *trb = r->trb;
 
+				trb = r->trb + i;
 				trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
 				dwc3_ep_inc_deq(dep);
-
-				if (r->needs_extra_trb) {
-					trb = r->trb + 1;
-					trb->ctrl &= ~DWC3_TRB_CTRL_HWO;
-					dwc3_ep_inc_deq(dep);
-				}
 			}
 			goto out1;
 		}
@@ -1441,8 +1423,6 @@ static int dwc3_gadget_ep_dequeue(struct usb_ep *ep,
 	}
 
 out1:
-	/* giveback the request */
-
 	dwc3_gadget_giveback(dep, req, -ECONNRESET);
 
 out0: