usb: cdns3: ep0: add spinlock for cdns3_check_new_setup

The other thread may access other endpoints when the cdns3_check_new_setup
is handling, add spinlock to protect it.

Fixes: 7733f6c32e ("usb: cdns3: Add Cadence USB3 DRD Driver")
Cc: <stable@vger.kernel.org>
Reviewed-by: Pawel Laszczak <pawell@cadence.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20200623030918.8409-4-peter.chen@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/cdns3/ep0.c

@@ -705,15 +705,17 @@ static int cdns3_gadget_ep0_queue(struct usb_ep *ep,
 	int ret = 0;
 	u8 zlp = 0;
 
+	spin_lock_irqsave(&priv_dev->lock, flags);
 	trace_cdns3_ep0_queue(priv_dev, request);
 
 	/* cancel the request if controller receive new SETUP packet. */
-	if (cdns3_check_new_setup(priv_dev))
+	if (cdns3_check_new_setup(priv_dev)) {
+		spin_unlock_irqrestore(&priv_dev->lock, flags);
 		return -ECONNRESET;
+	}
 
 	/* send STATUS stage. Should be called only for SET_CONFIGURATION */
 	if (priv_dev->ep0_stage == CDNS3_STATUS_STAGE) {
-		spin_lock_irqsave(&priv_dev->lock, flags);
 		cdns3_select_ep(priv_dev, 0x00);
 
 		erdy_sent = !priv_dev->hw_configured_flag;
@@ -738,7 +740,6 @@ static int cdns3_gadget_ep0_queue(struct usb_ep *ep,
 		return 0;
 	}
 
-	spin_lock_irqsave(&priv_dev->lock, flags);
 	if (!list_empty(&priv_ep->pending_req_list)) {
 		dev_err(priv_dev->dev,
 			"can't handle multiple requests for ep0\n");