Currently, loops_per_jiffy is being calculated twice for
non-SMP processors.
- Before calling cpufreq_notify_transition()
- From within cpufreq_notify_transition()
Double adjustment leads to incorrect value being assigned to
loops_per_jiffy. This manifests as incorrect BogoMIPS in
"cat /proc/cpuinfo".
The value of loops_per_jiffy needs to be calculated only
when CONFIG_SMP is true. It is the core change included
in this patch.
The patch also leverages the definition of for_each_cpu()
with and without CONFIG_SMP to consolidate the mechanism
to call cpufreq_notify_transition().
Signed-off-by: Sanjeev Premi <premi@xxxxxx>
---
Changes since v1:
* loops_per_jiffy are updated when CONFIG_SMP is true.
* leverage definition of for_each_cpu()
Tested on OMAP3EVM with and without CONFIG_SMP.
Since the log is rather long, will be posting the log in
a follow-up mail.
arch/arm/mach-omap2/omap2plus-cpufreq.c | 27 +++++++++++++++------------
1 files changed, 15 insertions(+), 12 deletions(-)
diff --git a/arch/arm/mach-omap2/omap2plus-cpufreq.c b/arch/arm/mach-omap2/omap2plus-cpufreq.c
index 346519e..0263cae 100644
--- a/arch/arm/mach-omap2/omap2plus-cpufreq.c
+++ b/arch/arm/mach-omap2/omap2plus-cpufreq.c
@@ -97,12 +97,8 @@ static int omap_target(struct cpufreq_policy *policy,
return ret;
/* Notify transitions */
- if (is_smp()) {
- for_each_cpu(i, policy->cpus) {
- freqs.cpu = i;
- cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
- }
- } else {
+ for_each_cpu(i, policy->cpus) {
+ freqs.cpu = i;
cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
}
@@ -114,13 +110,20 @@ static int omap_target(struct cpufreq_policy *policy,
freqs.new = omap_getspeed(policy->cpu);
+#ifdef CONFIG_SMP
+ /* Adjust jiffies before transition */
+ for_each_cpu(i, policy->cpus) {
+ unsigned long lpj = per_cpu(cpu_data, i).loops_per_jiffy;
+
+ per_cpu(cpu_data, i).loops_per_jiffy = cpufreq_scale(lpj,
+ freqs.old,
+ freqs.new);
+ }
+#endif
+
/* Notify transitions */
- if (is_smp()) {
- for_each_cpu(i, policy->cpus) {
- freqs.cpu = i;
- cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
- }
- } else {
+ for_each_cpu(i, policy->cpus) {
+ freqs.cpu = i;
cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
}
--
1.7.2.2
--
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