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From 1d59e428d7754c0fc331092d265254a0b3473546 Mon Sep 17 00:00:00 2001
From: Gerd Hoffmann <kraxel@redhat.com>
Date: Wed, 11 Dec 2013 10:04:22 +0100
Subject: [PATCH 1/5] xhci: add support for suspend/resume

RH-Author: Gerd Hoffmann <kraxel@redhat.com>
Message-id: <1386756262-29763-2-git-send-email-kraxel@redhat.com>
Patchwork-id: 56161
O-Subject: [RHEL-7 qemu-kvm PATCH 1/1] xhci: add support for suspend/resume
Bugzilla: 1012365
RH-Acked-by: Laszlo Ersek <lersek@redhat.com>
RH-Acked-by: Paolo Bonzini <pbonzini@redhat.com>
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>

The OS can ask the xhci controller to save and restore its
internal state, which is used by the OS when the system is
suspended and resumed.

This patch handles writes to the save + restore bits in the
command register.  Only thing it does is updating the
restore error bit in the status register to signal an error
on restore.  The guest OS should do a full reinitialization
after resume then.

This is the minimal patch which gets S3 going with xhci.
Implementing full save/restore support is TBD.

https://bugzilla.redhat.com/show_bug.cgi?id=1012365

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
(cherry picked from commit f1f8bc218a422081f36f0b325b3de5e6a5078b74)
---
 hw/usb/hcd-xhci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com>
---
 hw/usb/hcd-xhci.c |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/hw/usb/hcd-xhci.c b/hw/usb/hcd-xhci.c
index 9d7315f..87ba7af 100644
--- a/hw/usb/hcd-xhci.c
+++ b/hw/usb/hcd-xhci.c
@@ -2976,6 +2976,14 @@ static void xhci_oper_write(void *ptr, hwaddr reg,
         } else if (!(val & USBCMD_RS) && (xhci->usbcmd & USBCMD_RS)) {
             xhci_stop(xhci);
         }
+        if (val & USBCMD_CSS) {
+            /* save state */
+            xhci->usbsts &= ~USBSTS_SRE;
+        }
+        if (val & USBCMD_CRS) {
+            /* restore state */
+            xhci->usbsts |= USBSTS_SRE;
+        }
         xhci->usbcmd = val & 0xc0f;
         xhci_mfwrap_update(xhci);
         if (val & USBCMD_HCRST) {
-- 
1.7.1