From: Zhuang Jin Can <jin.can.zhuang@intel.com>
Date: Tue, 21 Jul 2015 14:20:31 +0000 (+0300)
Subject: xhci: do not report PLC when link is in internal resume state
X-Git-Tag: v3.2.71~11
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=6db7fe2b119d350fbe755e8f0babb51638f6fc85;p=thirdparty%2Fkernel%2Fstable.git

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

commit aca3a0489ac019b58cf32794d5362bb284cb9b94 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>
---

diff --git a/drivers/usb/host/xhci-hub.c b/drivers/usb/host/xhci-hub.c
index 353fe60e8e90c..860581308f87c 100644
--- a/drivers/usb/host/xhci-hub.c
+++ b/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;