[CPUFREQ] Bug fix for acpi-cpufreq and cpufreq_stats oops on frequency change notification
Fixes the oops in cpufreq_stats with acpi_cpufreq driver. The issue was
that the frequency was reported as 0 in acpi-cpufreq.c. The bug is due to
different indicies for freq_table and ACPI perf table.
Also adds a check in cpufreq_stats to check for error return from
freq_table_get_index() and avoid using the error return value.
Patch fixes the issue reported at
http://www.ussg.iu.edu/hypermail/linux/kernel/0611.2/0629.html
and also other similar issue here
http://bugme.osdl.org/show_bug.cgi?id=7383 comment 53
Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Dave Jones <davej@redhat.com>
diff --git a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
index b735458..563dcc8 100644
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -373,8 +373,8 @@
cpumask_t online_policy_cpus;
struct drv_cmd cmd;
unsigned int msr;
- unsigned int next_state = 0;
- unsigned int next_perf_state = 0;
+ unsigned int next_state = 0; /* Index into freq_table */
+ unsigned int next_perf_state = 0; /* Index into perf table */
unsigned int i;
int result = 0;
@@ -439,8 +439,8 @@
else
cpu_set(policy->cpu, cmd.mask);
- freqs.old = data->freq_table[perf->state].frequency;
- freqs.new = data->freq_table[next_perf_state].frequency;
+ freqs.old = perf->states[perf->state].core_frequency * 1000;
+ freqs.new = data->freq_table[next_state].frequency;
for_each_cpu_mask(i, cmd.mask) {
freqs.cpu = i;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
@@ -677,6 +677,7 @@
valid_states++;
}
data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
+ perf->state = 0;
result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
if (result)
diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c
index 6742b1a..91ad342 100644
--- a/drivers/cpufreq/cpufreq_stats.c
+++ b/drivers/cpufreq/cpufreq_stats.c
@@ -285,6 +285,7 @@
stat = cpufreq_stats_table[freq->cpu];
if (!stat)
return 0;
+
old_index = freq_table_get_index(stat, freq->old);
new_index = freq_table_get_index(stat, freq->new);
@@ -292,6 +293,9 @@
if (old_index == new_index)
return 0;
+ if (old_index == -1 || new_index == -1)
+ return 0;
+
spin_lock(&cpufreq_stats_lock);
stat->last_index = new_index;
#ifdef CONFIG_CPU_FREQ_STAT_DETAILS