From 73000192d12ef78cc46b9f13c65be357d8080e60 Mon Sep 17 00:00:00 2001 From: Riwen Lu Date: Wed, 12 Jun 2024 19:46:31 +0800 Subject: [PATCH] cpufreq/cppc: Don't compare desired_perf in target() BugLink: https://bugs.launchpad.net/bugs/2088114 There is a corner case where the desired_perf is exactly same as the old perf, but the actual current freq is not. This happens during S3 while the cpufreq governor is set to powersave. During cpufreq resume process, the booting CPU's new_freq obtained via .get() is the highest frequency, while the policy->cur and cpu->perf_ctrls.desired_perf are set to the lowest level (powersave governor). This causes the warning: "CPU frequency out of sync:", and the cpufreq core sets policy->cur to new_freq. Then the governor->limits() calls cppc_cpufreq_set_target() to configures the CPU frequency and returns directly because the desired_perf converted from target_freq is same as the cpu->perf_ctrls.desired_perf and both are the lowest_perf. Since target_freq and policy->cur have been already compared in __cpufreq_driver_target(), there's no need to compare them again here. Drop the comparison. Signed-off-by: Riwen Lu [ Viresh: Updated commit message / subject ] Signed-off-by: Viresh Kumar (cherry picked from commit 90e4ed6bb02ad93663f17411d17e8e714a765a6b) Signed-off-by: Jamie Nguyen Acked-by: Brad Figg Acked-by: Jacob Martin Acked-by: Noah Wager Signed-off-by: Brad Figg --- drivers/cpufreq/cppc_cpufreq.c | 9 ++------- 1 file changed, 2 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cppc_cpufreq.c b/drivers/cpufreq/cppc_cpufreq.c index 951614d84def..1e8fa249a1c4 100644 --- a/drivers/cpufreq/cppc_cpufreq.c +++ b/drivers/cpufreq/cppc_cpufreq.c @@ -275,15 +275,10 @@ static int cppc_cpufreq_set_target(struct cpufreq_policy *policy, struct cppc_cpudata *cpu_data = policy->driver_data; unsigned int cpu = policy->cpu; struct cpufreq_freqs freqs; - u32 desired_perf; int ret = 0; - desired_perf = cppc_khz_to_perf(&cpu_data->perf_caps, target_freq); - /* Return if it is exactly the same perf */ - if (desired_perf == cpu_data->perf_ctrls.desired_perf) - return ret; - - cpu_data->perf_ctrls.desired_perf = desired_perf; + cpu_data->perf_ctrls.desired_perf = + cppc_khz_to_perf(&cpu_data->perf_caps, target_freq); freqs.old = policy->cur; freqs.new = target_freq;