From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: [PATCH] cpufreq: Call cpufreq_disable_fast_switch() in sugov_exit() Date: Thu, 07 Apr 2016 23:38:46 +0200 Message-ID: <2791888.n2Juh7mFmz@vostro.rjw.lan> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: Received: from cloudserver094114.home.net.pl ([79.96.170.134]:61730 "HELO cloudserver094114.home.net.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1752883AbcDGVgP (ORCPT ); Thu, 7 Apr 2016 17:36:15 -0400 Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Linux PM list Cc: Linux Kernel Mailing List , Viresh Kumar , Peter Zijlstra , Srinivas Pandruvada From: Rafael J. Wysocki Due to differences in the cpufreq core's handling of runtime CPU offline and nonboot CPUs disabling during system suspend-to-RAM, fast frequency switching gets disabled after a suspend-to-RAM and resume cycle on all of the nonboot CPUs. To prevent that from happening, move the invocation of cpufreq_disable_fast_switch() from cpufreq_exit_governor() to sugov_exit(), as the schedutil governor is the only user of fast frequency switching today anyway. That simply prevents cpufreq_disable_fast_switch() from being called without invoking the ->governor callback for the CPUFREQ_GOV_POLICY_EXIT event (which happens during system suspend now). Fixes: b7898fda5bc7 (cpufreq: Support for fast frequency switching) Signed-off-by: Rafael J. Wysocki --- On top of linux-next. --- drivers/cpufreq/cpufreq.c | 19 +++++++++++-------- include/linux/cpufreq.h | 1 + kernel/sched/cpufreq_schedutil.c | 2 ++ 3 files changed, 14 insertions(+), 8 deletions(-) Index: linux-pm/drivers/cpufreq/cpufreq.c =================================================================== --- linux-pm.orig/drivers/cpufreq/cpufreq.c +++ linux-pm/drivers/cpufreq/cpufreq.c @@ -77,7 +77,11 @@ static inline bool has_target(void) static int cpufreq_governor(struct cpufreq_policy *policy, unsigned int event); static unsigned int __cpufreq_get(struct cpufreq_policy *policy); static int cpufreq_start_governor(struct cpufreq_policy *policy); -static int cpufreq_exit_governor(struct cpufreq_policy *policy); + +static inline int cpufreq_exit_governor(struct cpufreq_policy *policy) +{ + return cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); +} /** * Two notifier lists: the "policy" list is involved in the @@ -482,7 +486,11 @@ void cpufreq_enable_fast_switch(struct c } EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); -static void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) +/** + * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. + * @policy: cpufreq policy to disable fast frequency switching for. + */ +void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) { mutex_lock(&cpufreq_fast_switch_lock); if (policy->fast_switch_enabled) { @@ -492,6 +500,7 @@ static void cpufreq_disable_fast_switch( } mutex_unlock(&cpufreq_fast_switch_lock); } +EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); /********************************************************************* * SYSFS INTERFACE * @@ -2060,12 +2069,6 @@ static int cpufreq_start_governor(struct return ret ? ret : cpufreq_governor(policy, CPUFREQ_GOV_LIMITS); } -static int cpufreq_exit_governor(struct cpufreq_policy *policy) -{ - cpufreq_disable_fast_switch(policy); - return cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); -} - int cpufreq_register_governor(struct cpufreq_governor *governor) { int err; Index: linux-pm/include/linux/cpufreq.h =================================================================== --- linux-pm.orig/include/linux/cpufreq.h +++ linux-pm/include/linux/cpufreq.h @@ -168,6 +168,7 @@ int cpufreq_update_policy(unsigned int c bool have_governor_per_policy(void); struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy); void cpufreq_enable_fast_switch(struct cpufreq_policy *policy); +void cpufreq_disable_fast_switch(struct cpufreq_policy *policy); #else static inline unsigned int cpufreq_get(unsigned int cpu) { Index: linux-pm/kernel/sched/cpufreq_schedutil.c =================================================================== --- linux-pm.orig/kernel/sched/cpufreq_schedutil.c +++ linux-pm/kernel/sched/cpufreq_schedutil.c @@ -398,6 +398,8 @@ static int sugov_exit(struct cpufreq_pol struct sugov_tunables *tunables = sg_policy->tunables; unsigned int count; + cpufreq_disable_fast_switch(policy); + mutex_lock(&global_tunables_lock); count = gov_attr_set_put(&tunables->attr_set, &sg_policy->tunables_hook);