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Diffstat (limited to 'arch/x86/kernel/cpu/cpufreq/powernow-k8.c')
-rw-r--r--arch/x86/kernel/cpu/cpufreq/powernow-k8.c18
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 d3dcd58b87cd..7f05f44b97e9 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)) {
/*