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| author | Afzal Mohammed <afzal@ti.com> | 2012-01-04 10:52:31 +0530 |
|---|---|---|
| committer | Dave Jones <davej@redhat.com> | 2012-01-06 10:10:53 -0500 |
| commit | 226dd0193f9b8524789a86505ba05b1a74d916c1 (patch) | |
| tree | 3a3024b8b507defa98f5f704618327a4dcfbc6e4 /drivers/cpufreq/cpufreq_userspace.c | |
| parent | 21f2e3c86b3746aaa462f9a2734363f4f41a641c (diff) | |
| download | linux-226dd0193f9b8524789a86505ba05b1a74d916c1.tar.gz | |
[CPUFREQ] cpufreq:userspace: fix cpu_cur_freq updation
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>
Diffstat (limited to 'drivers/cpufreq/cpufreq_userspace.c')
| -rw-r--r-- | drivers/cpufreq/cpufreq_userspace.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/cpufreq/cpufreq_userspace.c b/drivers/cpufreq/cpufreq_userspace.c index f231015904c0..bedac1aa9be3 100644 --- a/drivers/cpufreq/cpufreq_userspace.c +++ b/drivers/cpufreq/cpufreq_userspace.c @@ -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; } |