Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: add X86_FEATURE_XMM4_2 definitions
  x86: fix cpufreq + sched_clock() regression
  x86: fix HPET regression in 2.6.26 versus 2.6.25, check hpet against BAR, v3
  x86: do not enable TSC notifier if we don't need it
  x86 MCE: Fix CPU hotplug problem with multiple multicore AMD CPUs
  x86: fix: make PCI ECS for AMD CPUs hotplug capable
  x86: fix: do not run code in amd_bus.c on non-AMD CPUs

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 46af71676738..8e786b0d665a 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -314,7 +314,7 @@ static int time_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
                         mark_tsc_unstable("cpufreq changes");
         }
 
-        set_cyc2ns_scale(tsc_khz_ref, freq->cpu);
+        set_cyc2ns_scale(tsc_khz, freq->cpu);
 
         return 0;
 }
@@ -325,6 +325,10 @@ static struct notifier_block time_cpufreq_notifier_block = {
 
 static int __init cpufreq_tsc(void)
 {
+        if (!cpu_has_tsc)
+                return 0;
+        if (boot_cpu_has(X86_FEATURE_CONSTANT_TSC))
+                return 0;
         cpufreq_register_notifier(&time_cpufreq_notifier_block,
                                 CPUFREQ_TRANSITION_NOTIFIER);
         return 0;