usb: dwc3: gadget: Clear ep descriptor last

Until the endpoint is disabled, its descriptors should remain valid.
When its requests are removed from ep disable, the request completion
routine may attempt to access the endpoint's descriptor. Don't clear the
descriptors before that.

Fixes: f09ddcf ("usb: dwc3: gadget: Prevent EP queuing while stopping transfers")
Cc: stable@vger.kernel.org
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/45db7c83b209259115bf652af210f8b2b3b1a383.1668561364.git.Thinh.Nguyen@synopsys.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Thinh Nguyen

drivers/usb/dwc3/gadget.c

@@ -1024,12 +1024,6 @@ static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
 	reg &= ~DWC3_DALEPENA_EP(dep->number);
 	dwc3_writel(dwc->regs, DWC3_DALEPENA, reg);
 
-	/* Clear out the ep descriptors for non-ep0 */
-	if (dep->number > 1) {
-		dep->endpoint.comp_desc = NULL;
-		dep->endpoint.desc = NULL;
-	}
-
 	dwc3_remove_requests(dwc, dep, -ESHUTDOWN);
 
 	dep->stream_capable = false;
@@ -1044,6 +1038,12 @@ static int __dwc3_gadget_ep_disable(struct dwc3_ep *dep)
 		mask |= (DWC3_EP_DELAY_STOP | DWC3_EP_TRANSFER_STARTED);
 	dep->flags &= mask;
 
+	/* Clear out the ep descriptors for non-ep0 */
+	if (dep->number > 1) {
+		dep->endpoint.comp_desc = NULL;
+		dep->endpoint.desc = NULL;
+	}
+
 	return 0;
 }