Patch "xhci: do not report PLC when link is in internal resume state" has been added to the 4.1-stable tree

Patch "xhci: do not report PLC when link is in internal resume state" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

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

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xhci-do-not-report-plc-when-link-is-in-internal-resume-state.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From aca3a0489ac019b58cf32794d5362bb284cb9b94 Mon Sep 17 00:00:00 2001
From: Zhuang Jin Can <jin.can.zhuang@intel.com>
Date: Tue, 21 Jul 2015 17:20:31 +0300
Subject: xhci: do not report PLC when link is in internal resume state

From: Zhuang Jin Can <jin.can.zhuang@intel.com>

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>

---
 drivers/usb/host/xhci-hub.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/usb/host/xhci-hub.c
+++ b/drivers/usb/host/xhci-hub.c
@@ -591,7 +591,14 @@ static u32 xhci_get_port_status(struct u
 		status |= USB_PORT_STAT_C_RESET << 16;
 	/* USB3.0 only */
 	if (hcd->speed == HCD_USB3) {
-		if ((raw_port_status & 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 ((raw_port_status & PORT_PLC) &&
+			(raw_port_status & PORT_PLS_MASK) != XDEV_RESUME)
 			status |= USB_PORT_STAT_C_LINK_STATE << 16;
 		if ((raw_port_status & PORT_WRC))
 			status |= USB_PORT_STAT_C_BH_RESET << 16;


Patches currently in stable-queue which might be from jin.can.zhuang@intel.com are

queue-4.1/xhci-do-not-report-plc-when-link-is-in-internal-resume-state.patch
queue-4.1/xhci-prevent-bus_suspend-if-ss-port-resuming-in-phase-1.patch
queue-4.1/xhci-report-u3-when-link-is-in-resume-state.patch