lkml.org 
[lkml]   [2013]   [Feb]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 1/4] cpufreq: governors: Fix WARN_ON() for multi-policy platforms
Date
On multi-policy systems there is a single instance of governor for both the
policies (if same governor is chosen for both policies). With the code update
from following patches:

8eeed09 cpufreq: governors: Get rid of dbs_data->enable field
b394058 cpufreq: governors: Reset tunables only for cpufreq_unregister_governor()

We are creating/removing sysfs directory of governor for for every call to
GOV_START and STOP. This would fail for multi-policy system as there is a
per-policy call to START/STOP.

This patch reuses the governor->initialized variable to detect total users of
governor.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
---
drivers/cpufreq/cpufreq.c | 6 ++++--
drivers/cpufreq/cpufreq_governor.c | 32 +++++++++++++++++++-------------
2 files changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index ccc598a..3b941a1 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1567,8 +1567,10 @@ static int __cpufreq_governor(struct cpufreq_policy *policy,
policy->cpu, event);
ret = policy->governor->governor(policy, event);

- if (!policy->governor->initialized && (event == CPUFREQ_GOV_START))
- policy->governor->initialized = 1;
+ if (event == CPUFREQ_GOV_START)
+ policy->governor->initialized++;
+ else if (event == CPUFREQ_GOV_STOP)
+ policy->governor->initialized--;

/* we keep one module reference alive for
each CPU governed by this CPU */
diff --git a/drivers/cpufreq/cpufreq_governor.c b/drivers/cpufreq/cpufreq_governor.c
index e4a306c..5a76086 100644
--- a/drivers/cpufreq/cpufreq_governor.c
+++ b/drivers/cpufreq/cpufreq_governor.c
@@ -247,11 +247,13 @@ int cpufreq_governor_dbs(struct dbs_data *dbs_data,
dbs_data->gov_dbs_timer);
}

- rc = sysfs_create_group(cpufreq_global_kobject,
- dbs_data->attr_group);
- if (rc) {
- mutex_unlock(&dbs_data->mutex);
- return rc;
+ if (!policy->governor->initialized) {
+ rc = sysfs_create_group(cpufreq_global_kobject,
+ dbs_data->attr_group);
+ if (rc) {
+ mutex_unlock(&dbs_data->mutex);
+ return rc;
+ }
}

/*
@@ -262,13 +264,15 @@ int cpufreq_governor_dbs(struct dbs_data *dbs_data,
cs_dbs_info->down_skip = 0;
cs_dbs_info->enable = 1;
cs_dbs_info->requested_freq = policy->cur;
- cpufreq_register_notifier(cs_ops->notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);

- if (!policy->governor->initialized)
+ if (!policy->governor->initialized) {
+ cpufreq_register_notifier(cs_ops->notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+
dbs_data->min_sampling_rate =
MIN_SAMPLING_RATE_RATIO *
jiffies_to_usecs(10);
+ }
} else {
od_dbs_info->rate_mult = 1;
od_dbs_info->sample_type = OD_NORMAL_SAMPLE;
@@ -311,11 +315,13 @@ unlock:
mutex_lock(&dbs_data->mutex);
mutex_destroy(&cpu_cdbs->timer_mutex);

- sysfs_remove_group(cpufreq_global_kobject,
- dbs_data->attr_group);
- if (dbs_data->governor == GOV_CONSERVATIVE)
- cpufreq_unregister_notifier(cs_ops->notifier_block,
- CPUFREQ_TRANSITION_NOTIFIER);
+ if (policy->governor->initialized == 1) {
+ sysfs_remove_group(cpufreq_global_kobject,
+ dbs_data->attr_group);
+ if (dbs_data->governor == GOV_CONSERVATIVE)
+ cpufreq_unregister_notifier(cs_ops->notifier_block,
+ CPUFREQ_TRANSITION_NOTIFIER);
+ }
mutex_unlock(&dbs_data->mutex);

break;
--
1.7.12.rc2.18.g61b472e



\
 
 \ /
  Last update: 2013-02-07 12:21    [W:0.111 / U:0.228 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site