From: Keir Fraser <keir.fraser@citrix.com>
Date: Thu, 8 Oct 2009 07:51:51 +0000 (+0100)
Subject: x86 tsc: Fix check_tsc_warp() bug and add copyright notice
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~13246
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22?a=commitdiff_plain;h=e82a2fb6080fa6cdb9f4baaf101b438baea07fc9;p=xen.git

x86 tsc: Fix check_tsc_warp() bug and add copyright notice

Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
Signed-off-by: Keir Fraser <keir.fraser@citrix.com>
---

diff --git a/xen/arch/x86/time.c b/xen/arch/x86/time.c
index 5a56b717c9..7f1a1153d7 100644
--- a/xen/arch/x86/time.c
+++ b/xen/arch/x86/time.c
@@ -1442,6 +1442,10 @@ struct tm wallclock_time(void)
  * TSC Reliability check
  */
 
+/*
+ * The Linux original version of this function is
+ * Copyright (c) 2006, Red Hat, Inc., Ingo Molnar
+ */
 void check_tsc_warp(unsigned long tsc_khz, unsigned long *max_warp)
 {
 #define rdtsc_barrier() mb()
@@ -1494,7 +1498,7 @@ void check_tsc_warp(unsigned long tsc_khz, unsigned long *max_warp)
         if ( unlikely(prev > now) )
         {
             spin_lock(&sync_lock);
-            if ( *max_warp > prev - now )
+            if ( *max_warp < prev - now )
                 *max_warp = prev - now;
             spin_unlock(&sync_lock);
         }