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authorVenkatesh Pallipadi <venkatesh.pallipadi@intel.com>2008-04-28 23:13:43 +0400
committerDave Jones <davej@redhat.com>2008-04-28 23:16:46 +0400
commite56a727b023d40d1adf660168883f30f2e6abe0a (patch)
treeb79841b8f4c79204b160bae2a6a61d8a62019c48
parentc938ac21329f19ad286eaaed7e26434943c8061b (diff)
downloadlinux-e56a727b023d40d1adf660168883f30f2e6abe0a.tar.xz
[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>
-rw-r--r--arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
index e2d870de837c..8db8f73503b3 100644
--- a/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/x86/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -339,6 +339,7 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
{
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 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
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;