From: Venkatesh Pallipadi 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 Signed-off-by: Venkatesh Pallipadi Cc: Dave Jones Signed-off-by: Andrew Morton --- arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c | 9 +++++---- drivers/cpufreq/cpufreq_stats.c | 4 ++++ 2 files changed, 9 insertions(+), 4 deletions(-) diff -puN arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c~bug-fix-for-acpi-cpufreq-and-cpufreq_stats-oops-on-frequency-change-notification arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c --- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c~bug-fix-for-acpi-cpufreq-and-cpufreq_stats-oops-on-frequency-change-notification +++ a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c @@ -390,8 +390,8 @@ static int acpi_cpufreq_target(struct cp 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; @@ -456,8 +456,8 @@ static int acpi_cpufreq_target(struct cp 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); @@ -694,6 +694,7 @@ static int acpi_cpufreq_cpu_init(struct 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 -puN drivers/cpufreq/cpufreq_stats.c~bug-fix-for-acpi-cpufreq-and-cpufreq_stats-oops-on-frequency-change-notification drivers/cpufreq/cpufreq_stats.c --- a/drivers/cpufreq/cpufreq_stats.c~bug-fix-for-acpi-cpufreq-and-cpufreq_stats-oops-on-frequency-change-notification +++ a/drivers/cpufreq/cpufreq_stats.c @@ -285,6 +285,7 @@ cpufreq_stat_notifier_trans (struct noti 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 @@ cpufreq_stat_notifier_trans (struct noti 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 _