sfi-cpufreq: remove reading the P state from the hardware

Reading the P state data from the HW MSR is actually undefined, and does
not work in various circumstances in practice. (The assumption that
you get a value back that you can match to your own table is very iffy
and not actually correct)
It's also not needed....

Change-Id: Ibb43a9b1752a858ad40fec8cadc402cf6bea2e31
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>

diff --git a/drivers/cpufreq/sfi-cpufreq.c b/drivers/cpufreq/sfi-cpufreq.c
index 5624f47..591d41e 100644 (file)
--- a/drivers/cpufreq/sfi-cpufreq.c
+++ b/drivers/cpufreq/sfi-cpufreq.c
@@ -1,7 +1,7 @@
 /*
  * sfi_cpufreq.c - sfi Processor P-States Driver
  *
- *
+ * (C) 2010-2011 Intel Corporation
  *
  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  *
@@ -58,8 +58,8 @@ static int sfi_cpufreq_num;
 static u32 sfi_cpu_num;
 
 #define                SFI_FREQ_MAX            32
-#define                INTEL_MSR_RANGE                         (0xffff)
-#define                SFI_CPU_MAX        8
+#define                INTEL_MSR_RANGE         (0xffff)
+#define                SFI_CPU_MAX             8
 
 
 struct sfi_cpufreq_data {
@@ -188,38 +188,9 @@ void sfi_processor_unregister_performance(struct sfi_processor_performance
        return;
 }
 
-static unsigned extract_freq(u32 msr, struct sfi_cpufreq_data *data)
-{
-       int i;
-       struct sfi_processor_performance *perf;
-
-       msr &= INTEL_MSR_RANGE;
-       perf = data->sfi_data;
-
-       for (i = 0; data->freq_table[i].frequency != CPUFREQ_TABLE_END; i++) {
-               if (msr == perf->states[data->freq_table[i].index].control)
-                       return data->freq_table[i].frequency;
-       }
-       return data->freq_table[0].frequency;
-}
-
-
-static u32 get_cur_val(const struct cpumask *mask)
-{
-       u32 val, dummy;
-
-       if (unlikely(cpumask_empty(mask)))
-               return 0;
-
-       rdmsr_on_cpu(cpumask_any(mask), MSR_IA32_PERF_STATUS, &val, &dummy);
-
-       return val;
-}
-
 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
 {
        struct sfi_cpufreq_data *data = per_cpu(drv_data, cpu);
-       unsigned int freq;
        unsigned int cached_freq;
 
        pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
@@ -230,18 +201,8 @@ static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
        }
 
        cached_freq = data->freq_table[data->sfi_data->state].frequency;
-       freq = extract_freq(get_cur_val(cpumask_of(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;
-       }
-
-       pr_debug("cur freq = %u\n", freq);
 
-       return freq;
+       return cached_freq;
 }
 
 static int sfi_cpufreq_target(struct cpufreq_policy *policy,