xhci: do not report PLC when link is in internal resume state

commit aca3a048 upstream.

Port link change with port in resume state should not be
reported to usbcore, as this is an internal state to be
handled by xhci driver. Reporting PLC to usbcore may
cause usbcore clearing PLC first and port change event irq
won't be generated.
Signed-off-by: Zhuang Jin Can <jin.can.zhuang@intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2:
 - Adjust indentation
 - s/raw_port_status/temp/]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/usb/host/xhci-hub.c

@@ -595,7 +595,14 @@ int xhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 			status |= USB_PORT_STAT_C_RESET << 16;
 		/* USB3.0 only */
 		if (hcd->speed == HCD_USB3) {
-			if ((temp & PORT_PLC))
+			/* Port link change with port in resume state should not be
+			 * reported to usbcore, as this is an internal state to be
+			 * handled by xhci driver. Reporting PLC to usbcore may
+			 * cause usbcore clearing PLC first and port change event
+			 * irq won't be generated.
+			 */
+			if ((temp & PORT_PLC) &&
+				(temp & PORT_PLS_MASK) != XDEV_RESUME)
 				status |= USB_PORT_STAT_C_LINK_STATE << 16;
 			if ((temp & PORT_WRC))
 				status |= USB_PORT_STAT_C_BH_RESET << 16;