1 files changed, 15 insertions, 3 deletions

diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index d3dcd58b87c..7f05f44b97e 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -115,9 +115,20 @@ static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
         u32 i = 0;
 
         if (cpu_family == CPU_HW_PSTATE) {
-                rdmsr(MSR_PSTATE_STATUS, lo, hi);
-                i = lo & HW_PSTATE_MASK;
-                data->currpstate = i;
+                if (data->currpstate == HW_PSTATE_INVALID) {
+                        /* read (initial) hw pstate if not yet set */
+                        rdmsr(MSR_PSTATE_STATUS, lo, hi);
+                        i = lo & HW_PSTATE_MASK;
+
+                        /*
+                         * a workaround for family 11h erratum 311 might cause
+                         * an "out-of-range Pstate if the core is in Pstate-0
+                         */
+                        if (i >= data->numps)
+                                data->currpstate = HW_PSTATE_0;
+                        else
+                                data->currpstate = i;
+                }
                 return 0;
         }
         do {
@@ -1121,6 +1132,7 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
         }
 
         data->cpu = pol->cpu;
+        data->currpstate = HW_PSTATE_INVALID;
 
         if (powernow_k8_cpu_init_acpi(data)) {
                 /*