[CPUFREQ] Make acpi-cpufreq more robust against BIOS freq changes behind our back.
We checked the hardware freq with OS cached freq value in get_cur_freqon_cpu().
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index e2d870d..8db8f73 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -339,6 +339,7 @@
{
struct acpi_cpufreq_data *data = per_cpu(drv_data, cpu);
unsigned int freq;
+ unsigned int cached_freq;
dprintk("get_cur_freq_on_cpu (%d)\n", cpu);
@@ -347,7 +348,16 @@
return 0;
}
+ cached_freq = data->freq_table[data->acpi_data->state].frequency;
freq = extract_freq(get_cur_val(&cpumask_of_cpu(cpu)), data);
+ if (freq != cached_freq) {
+ /*
+ * The dreaded BIOS frequency change behind our back.
+ * Force set the frequency on next target call.
+ */
+ data->resume = 1;
+ }
+
dprintk("cur freq = %u\n", freq);
return freq;