lkml.org 
[lkml]   [2016]   [May]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 2/2] cpufreq: governor: CPUFREQ_GOV_STOP never fails
Date
From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

None of the cpufreq governors currently in the tree will ever fail
an invocation of the ->governor() callback with the event argument
equal to CPUFREQ_GOV_STOP (unless invoked with incorrect arguments
which doesn't matter anyway) and it is rather difficult to imagine
a valid reason for such a failure.

Accordingly, rearrange the code in the core to make it clear that
this call never fails.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
drivers/cpufreq/cpufreq.c | 40 +++++++++++-----------------------------
1 file changed, 11 insertions(+), 29 deletions(-)

Index: linux-pm/drivers/cpufreq/cpufreq.c
===================================================================
--- linux-pm.orig/drivers/cpufreq/cpufreq.c
+++ linux-pm/drivers/cpufreq/cpufreq.c
@@ -83,6 +83,11 @@ static inline void cpufreq_exit_governor
(void)cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT);
}

+static inline void cpufreq_stop_governor(struct cpufreq_policy *policy)
+{
+ (void)cpufreq_governor(policy, CPUFREQ_GOV_STOP);
+}
+
/**
* Two notifier lists: the "policy" list is involved in the
* validation process for a new CPU frequency policy; the
@@ -1026,13 +1031,8 @@ static int cpufreq_add_policy_cpu(struct
return 0;

down_write(&policy->rwsem);
- if (has_target()) {
- ret = cpufreq_governor(policy, CPUFREQ_GOV_STOP);
- if (ret) {
- pr_err("%s: Failed to stop governor\n", __func__);
- goto unlock;
- }
- }
+ if (has_target())
+ cpufreq_stop_governor(policy);

cpumask_set_cpu(cpu, policy->cpus);

@@ -1041,8 +1041,6 @@ static int cpufreq_add_policy_cpu(struct
if (ret)
pr_err("%s: Failed to start governor\n", __func__);
}
-
-unlock:
up_write(&policy->rwsem);
return ret;
}
@@ -1354,11 +1352,8 @@ static void cpufreq_offline(unsigned int
}

down_write(&policy->rwsem);
- if (has_target()) {
- ret = cpufreq_governor(policy, CPUFREQ_GOV_STOP);
- if (ret)
- pr_err("%s: Failed to stop governor\n", __func__);
- }
+ if (has_target())
+ cpufreq_stop_governor(policy);

cpumask_clear_cpu(cpu, policy->cpus);

@@ -1622,7 +1617,6 @@ EXPORT_SYMBOL(cpufreq_generic_suspend);
void cpufreq_suspend(void)
{
struct cpufreq_policy *policy;
- int ret;

if (!cpufreq_driver)
return;
@@ -1635,14 +1629,8 @@ void cpufreq_suspend(void)
for_each_active_policy(policy) {
if (has_target()) {
down_write(&policy->rwsem);
- ret = cpufreq_governor(policy, CPUFREQ_GOV_STOP);
+ cpufreq_stop_governor(policy);
up_write(&policy->rwsem);
-
- if (ret) {
- pr_err("%s: Failed to stop governor for policy: %p\n",
- __func__, policy);
- continue;
- }
}

if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy))
@@ -2216,13 +2204,7 @@ static int cpufreq_set_policy(struct cpu
old_gov = policy->governor;
/* end old governor */
if (old_gov) {
- ret = cpufreq_governor(policy, CPUFREQ_GOV_STOP);
- if (ret) {
- /* This can happen due to race with other operations */
- pr_debug("%s: Failed to Stop Governor: %s (%d)\n",
- __func__, old_gov->name, ret);
- return ret;
- }
+ cpufreq_stop_governor(policy);
cpufreq_exit_governor(policy);
}

\
 
 \ /
  Last update: 2016-05-12 15:41    [W:0.051 / U:0.084 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site