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[CPUFREQ] cpufreq:userspace: fix cpu_cur_freq updation

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CPU frequency is guranteed to be changed on notifier callback with
CPUFREQ_POSTCHANGE. Notifier callback with CPUFREQ_PRECHANGE does
not gurantee a change in frequency; after it, if cpufreq driver is
unable to change CPU to new frequency. This results in wrong
information being fed to user (if setting CPU frequency fails)
upon doing like,

cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed

Hence in userspace governer update cpu_cur_freq only if notifier
has been called with POSTCHANGE.

Signed-off-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Dave Jones <davej@redhat.com>
This commit is contained in:
Afzal Mohammed 2012-01-04 10:52:31 +05:30 committed by Dave Jones
parent 21f2e3c86b
commit 226dd0193f
1 changed files with 5 additions and 3 deletions
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8
drivers/cpufreq/cpufreq_userspace.c
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@ -47,9 +47,11 @@ userspace_cpufreq_notifier(struct notifier_block *nb, unsigned long val,
if (!per_cpu(cpu_is_managed, freq->cpu))
return 0;
pr_debug("saving cpu_cur_freq of cpu %u to be %u kHz\n",
freq->cpu, freq->new);
per_cpu(cpu_cur_freq, freq->cpu) = freq->new;
if (val == CPUFREQ_POSTCHANGE) {
pr_debug("saving cpu_cur_freq of cpu %u to be %u kHz\n",
freq->cpu, freq->new);
per_cpu(cpu_cur_freq, freq->cpu) = freq->new;
}
return 0;
}