Hi,
As of linux-2.6.20-rc2 using acpi-cpufreq and ondemand on my Pentium M
(Asus V6VA laptop) seems broken.
/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq contains most of
the time 1, sometimes the actual frequency or (rarely) some random value.
The problem seems to come from
http://www.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=7650b281b091f39f5e97f13b45ab3813b1526b65
The attached patch fixes the problem for me, but it was obtained from
random mutilations of the aforementioned patch. For instance, I don't
understand how cmd.val is used, the freqs.old = extract_freq(cmd.val,
data); I introduced seems to use an uninitialized value from reading the
code. But it seems to be also the case in cmd.val = (cmd.val &
~INTEL_MSR_RANGE) | msr;
Thanks.
--
Guillaume
--- a/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
+++ b/arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c
@@ -400,6 +400,8 @@ static int acpi_cpufreq_target(struct cp
online_policy_cpus = policy->cpus;
#endif
+ freqs.old = extract_freq(cmd.val, data);
+ freqs.new = data->freq_table[next_state].frequency;
next_perf_state = data->freq_table[next_state].index;
if (perf->state == next_perf_state) {
if (unlikely(data->resume)) {
@@ -439,8 +441,6 @@ 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;
for_each_cpu_mask(i, cmd.mask) {
freqs.cpu = i;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
