From 1c534352f47fd83eb08075ac2474f707e74bf7f7 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Fri, 23 Oct 2020 17:35:19 +0200 Subject: cpufreq: Introduce CPUFREQ_NEED_UPDATE_LIMITS driver flag Generally, a cpufreq driver may need to update some internal upper and lower frequency boundaries on policy max and min changes, respectively, but currently this does not work if the target frequency does not change along with the policy limit. Namely, if the target frequency does not change along with the policy min or max, the "target_freq == policy->cur" check in __cpufreq_driver_target() prevents driver callbacks from being invoked and they do not even have a chance to update the corresponding internal boundary. This particularly affects the "powersave" and "performance" governors that always set the target frequency to one of the policy limits and it never changes when the other limit is updated. To allow cpufreq the drivers needing to update internal frequency boundaries on policy limits changes to avoid this issue, introduce a new driver flag, CPUFREQ_NEED_UPDATE_LIMITS, that (when set) will neutralize the check mentioned above. Signed-off-by: Rafael J. Wysocki Acked-by: Viresh Kumar --- drivers/cpufreq/cpufreq.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers') diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index f4b60663efe6..ea58337fb65f 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2187,7 +2187,8 @@ 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) + if (target_freq == policy->cur && + !(cpufreq_driver->flags & CPUFREQ_NEED_UPDATE_LIMITS)) return 0; /* Save last value to restore later on errors */ -- cgit v1.2.3