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-rw-r--r--arch/x86/kernel/cpu/cpufreq/powernow-k8.c28
1 files changed, 22 insertions, 6 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
index 5c28b37dea1..fb039cd345d 100644
--- a/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
+++ b/arch/x86/kernel/cpu/cpufreq/powernow-k8.c
@@ -939,10 +939,25 @@ static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
free_cpumask_var(data->acpi_data.shared_cpu_map);
}
+static int get_transition_latency(struct powernow_k8_data *data)
+{
+ int max_latency = 0;
+ int i;
+ for (i = 0; i < data->acpi_data.state_count; i++) {
+ int cur_latency = data->acpi_data.states[i].transition_latency
+ + data->acpi_data.states[i].bus_master_latency;
+ if (cur_latency > max_latency)
+ max_latency = cur_latency;
+ }
+ /* value in usecs, needs to be in nanoseconds */
+ return 1000 * max_latency;
+}
+
#else
static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data) { return -ENODEV; }
static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data) { return; }
static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data, unsigned int index) { return; }
+static int get_transition_latency(struct powernow_k8_data *data) { return 0; }
#endif /* CONFIG_X86_POWERNOW_K8_ACPI */
/* Take a frequency, and issue the fid/vid transition command */
@@ -1173,7 +1188,13 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
if (rc) {
goto err_out;
}
- }
+ /* Take a crude guess here.
+ * That guess was in microseconds, so multiply with 1000 */
+ pol->cpuinfo.transition_latency = (
+ ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
+ ((1 << data->irt) * 30)) * 1000;
+ } else /* ACPI _PSS objects available */
+ pol->cpuinfo.transition_latency = get_transition_latency(data);
/* only run on specific CPU from here on */
oldmask = current->cpus_allowed;
@@ -1204,11 +1225,6 @@ static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
cpumask_copy(pol->cpus, &per_cpu(cpu_core_map, pol->cpu));
data->available_cores = pol->cpus;
- /* Take a crude guess here.
- * That guess was in microseconds, so multiply with 1000 */
- pol->cpuinfo.transition_latency = (((data->rvo + 8) * data->vstable * VST_UNITS_20US)
- + (3 * (1 << data->irt) * 10)) * 1000;
-
if (cpu_family == CPU_HW_PSTATE)
pol->cur = find_khz_freq_from_pstate(data->powernow_table, data->currpstate);
else