usb:cdns3: Fix for CV CH9 running with g_zero driver.

Patch fixes issue with Halt Endnpoint Test observed during using g_zero
driver as DUT. Bug occurred only on some testing board.

Endpoint can defer transition to Halted state if endpoint has pending
requests.
Patch add additional condition that allows to return correct endpoint
status during Get Endpoint Status request even if the halting endpoint
is in progress.
Reported-by: Rahul Kumar <kurahul@cadence.com>
Signed-off-by: Rahul Kumar <kurahul@cadence.com>
Signed-off-by: Pawel Laszczak <pawell@cadence.com>
Fixes: 7733f6c3 ("usb: cdns3: Add Cadence USB3 DRD Driver")
Tested-by: Roger Quadros <rogerq@ti.com>
Link: https://lore.kernel.org/r/1570430355-26118-1-git-send-email-pawell@cadence.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/cdns3/ep0.c

@@ -234,9 +234,11 @@ static int cdns3_req_ep0_set_address(struct cdns3_device *priv_dev,
 static int cdns3_req_ep0_get_status(struct cdns3_device *priv_dev,
 				    struct usb_ctrlrequest *ctrl)
 {
+	struct cdns3_endpoint *priv_ep;
 	__le16 *response_pkt;
 	u16 usb_status = 0;
 	u32 recip;
+	u8 index;
 
 	recip = ctrl->bRequestType & USB_RECIP_MASK;
 
@@ -262,9 +264,13 @@ static int cdns3_req_ep0_get_status(struct cdns3_device *priv_dev,
 	case USB_RECIP_INTERFACE:
 		return cdns3_ep0_delegate_req(priv_dev, ctrl);
 	case USB_RECIP_ENDPOINT:
-		/* check if endpoint is stalled */
+		index = cdns3_ep_addr_to_index(ctrl->wIndex);
+		priv_ep = priv_dev->eps[index];
+
+		/* check if endpoint is stalled or stall is pending */
 		cdns3_select_ep(priv_dev, ctrl->wIndex);
-		if (EP_STS_STALL(readl(&priv_dev->regs->ep_sts)))
+		if (EP_STS_STALL(readl(&priv_dev->regs->ep_sts)) ||
+		    (priv_ep->flags & EP_STALL_PENDING))
 			usb_status =  BIT(USB_ENDPOINT_HALT);
 		break;
 	default: