From: Viresh Kumar <viresh.kumar@linaro.org> driver inclusion category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9163 ---------------------------------------------------------------------- Drivers setting CPUFREQ_NEED_UPDATE_LIMITS expect target() to be invoked even if the target frequency remains unchanged, so they can update their internal policy limits state. Currently the core invokes target() unconditionally whenever the requested frequency matches policy->cur for such drivers, even if policy->min and policy->max haven't changed since the previous update. Track pending policy limit updates explicitly and skip redundant target() invocations when neither the target frequency nor the effective limits changed. Fixes: 1c534352f47f ("cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag") Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Lifeng Zheng <zhenglifeng1@huawei.com> Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> Signed-off-by: Hongye Lin <linhongye@h-partners.com> --- drivers/cpufreq/cpufreq.c | 31 ++++++++++++++++++++++--------- include/linux/cpufreq.h | 3 +++ 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 2971d5862b33..f12b03e305df 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2371,9 +2371,13 @@ int __cpufreq_driver_target(struct cpufreq_policy *policy, * exactly same freq is called again and so we can save on few function * calls. */ - if (target_freq == policy->cur && - !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS)) - return 0; + if (target_freq == policy->cur) { + if (!(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS) || + !policy->update_limits) + return 0; + + policy->update_limits = false; + } if (cpufreq_driver->target) { /* @@ -2622,6 +2626,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, { struct cpufreq_policy_data new_data; struct cpufreq_governor *old_gov; + unsigned int freq; int ret; memcpy(&new_data.cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); @@ -2654,12 +2659,20 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, * compiler optimizations around them because they may be accessed * concurrently by cpufreq_driver_resolve_freq() during the update. */ - WRITE_ONCE(policy->max, __resolve_freq(policy, new_data.max, - new_data.min, new_data.max, - CPUFREQ_RELATION_H)); - new_data.min = __resolve_freq(policy, new_data.min, new_data.min, - new_data.max, CPUFREQ_RELATION_L); - WRITE_ONCE(policy->min, new_data.min > policy->max ? policy->max : new_data.min); + freq = __resolve_freq(policy, new_data.max, new_data.min, new_data.max, + CPUFREQ_RELATION_H); + if (freq != policy->max) { + WRITE_ONCE(policy->max, freq); + policy->update_limits = true; + } + + freq = __resolve_freq(policy, new_data.min, new_data.min, new_data.max, + CPUFREQ_RELATION_L); + freq = min(freq, policy->max); + if (freq != policy->min) { + WRITE_ONCE(policy->min, freq); + policy->update_limits = true; + } trace_cpu_frequency_limits(policy); diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index b653a26a663b..7050ebd47ab2 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -150,6 +150,9 @@ struct cpufreq_policy { /* Per policy boost enabled flag. */ bool boost_enabled; + /* Pending policy->min/max update for the driver */ + bool update_limits; + /* Cached frequency lookup from cpufreq_driver_resolve_freq. */ unsigned int cached_target_freq; unsigned int cached_resolved_idx; -- 2.33.0