msm: cpufreq: Implement suspend/resume for cpufreq driver
Cpufreq suspend variable get's updated in kernel pm notifier
callback which gets called in process context. This will create
window where cpufreq governor may try to change the frequency
before suspend variable is updated while resume.
Define suspend/resume for cpufreq driver to update suspend variable
in atomic context.
Don't update the policy->cur upon cpufreq driver failure.
CRs-fixed: 423791
Change-Id: Id78705f5c3b8bf801c6253e9362299280903769f
Signed-off-by: Anji Jonnala <anjir@codeaurora.org>
diff --git a/arch/arm/mach-msm/cpufreq.c b/arch/arm/mach-msm/cpufreq.c
index 6c9b413..77bb00f 100644
--- a/arch/arm/mach-msm/cpufreq.c
+++ b/arch/arm/mach-msm/cpufreq.c
@@ -278,20 +278,24 @@
.notifier_call = msm_cpufreq_cpu_callback,
};
-static int msm_cpufreq_suspend(void)
+/*
+ * Define suspend/resume for cpufreq_driver. Kernel will call
+ * these during suspend/resume with interrupts disabled. This
+ * helps the suspend/resume variable get's updated before cpufreq
+ * governor tries to change the frequency after coming out of suspend.
+ */
+static int msm_cpufreq_suspend(struct cpufreq_policy *policy)
{
int cpu;
for_each_possible_cpu(cpu) {
- mutex_lock(&per_cpu(cpufreq_suspend, cpu).suspend_mutex);
per_cpu(cpufreq_suspend, cpu).device_suspended = 1;
- mutex_unlock(&per_cpu(cpufreq_suspend, cpu).suspend_mutex);
}
- return NOTIFY_DONE;
+ return 0;
}
-static int msm_cpufreq_resume(void)
+static int msm_cpufreq_resume(struct cpufreq_policy *policy)
{
int cpu;
@@ -299,28 +303,9 @@
per_cpu(cpufreq_suspend, cpu).device_suspended = 0;
}
- return NOTIFY_DONE;
+ return 0;
}
-static int msm_cpufreq_pm_event(struct notifier_block *this,
- unsigned long event, void *ptr)
-{
- switch (event) {
- case PM_POST_HIBERNATION:
- case PM_POST_SUSPEND:
- return msm_cpufreq_resume();
- case PM_HIBERNATION_PREPARE:
- case PM_SUSPEND_PREPARE:
- return msm_cpufreq_suspend();
- default:
- return NOTIFY_DONE;
- }
-}
-
-static struct notifier_block msm_cpufreq_pm_notifier = {
- .notifier_call = msm_cpufreq_pm_event,
-};
-
static struct freq_attr *msm_freq_attr[] = {
&cpufreq_freq_attr_scaling_available_freqs,
NULL,
@@ -333,6 +318,8 @@
.verify = msm_cpufreq_verify,
.target = msm_cpufreq_target,
.get = msm_cpufreq_get_freq,
+ .suspend = msm_cpufreq_suspend,
+ .resume = msm_cpufreq_resume,
.name = "msm",
.attr = msm_freq_attr,
};
@@ -348,7 +335,6 @@
register_hotcpu_notifier(&msm_cpufreq_cpu_notifier);
- register_pm_notifier(&msm_cpufreq_pm_notifier);
return cpufreq_register_driver(&msm_cpufreq_driver);
}