linux-kernel - Re: [PATCH Resend] cpufreq: remove sysfs files for CPU which failed to come back after resume

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Date:	Mon, 23 Dec 2013 21:15:40 +0530
From:	viresh kumar <viresh.kumar@...aro.org>
To:	Bjørn Mork <bjorn@...k.no>
CC:	"Rafael J. Wysocki" <rjw@...ysocki.net>,
	"cpufreq@...r.kernel.org" <cpufreq@...r.kernel.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH Resend] cpufreq: remove sysfs files for CPU which failed
 to come back after resume

On Monday 23 December 2013 05:12 PM, Bjørn Mork wrote:
> That would be great.  This could be just me.  I am quite good at
> breaking stuff.

No its not you. While we tried to make sure everything is preserved,
few special things still stayed out :)

And they are solved with this patch, log should be good enough to give
proper reasoning:

From: Viresh Kumar <viresh.kumar@...aro.org>
Date: Mon, 23 Dec 2013 20:51:54 +0530
Subject: [PATCH] cpufreq: preserve user_policy across suspend/resume

In __cpufreq_add_dev() we are reinitializing user_policy with default values and
hence would loose values of user_policy.{min|max|policy|governor} fields.

Preserve them by not overriding these for suspend/resume.

Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/cpufreq.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 16d7b4a..c5c3dac 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -839,9 +839,6 @@ static void cpufreq_init_policy(struct cpufreq_policy *policy)

 	/* set default policy */
 	ret = cpufreq_set_policy(policy, &new_policy);
-	policy->user_policy.policy = policy->policy;
-	policy->user_policy.governor = policy->governor;
-
 	if (ret) {
 		pr_debug("setting policy failed\n");
 		if (cpufreq_driver->exit)
@@ -1069,8 +1066,10 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,
 	 */
 	cpumask_and(policy->cpus, policy->cpus, cpu_online_mask);

-	policy->user_policy.min = policy->min;
-	policy->user_policy.max = policy->max;
+	if (!frozen) {
+		policy->user_policy.min = policy->min;
+		policy->user_policy.max = policy->max;
+	}

 	blocking_notifier_call_chain(&cpufreq_policy_notifier_list,
 				     CPUFREQ_START, policy);
@@ -1101,6 +1100,11 @@ static int __cpufreq_add_dev(struct device *dev, struct subsys_interface *sif,

 	cpufreq_init_policy(policy);

+	if (!frozen) {
+		policy->user_policy.policy = policy->policy;
+		policy->user_policy.governor = policy->governor;
+	}
+
 	kobject_uevent(&policy->kobj, KOBJ_ADD);
 	up_read(&cpufreq_rwsem);


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