From: Lifeng Zheng <zhenglifeng1@huawei.com> commit 1608f0230510489d74a2e24e47054233b7e4678a upstream. It turns out that CPUX will stay on the base frequency after performing these operations: 1. boost all CPUs: echo 1 > /sys/devices/system/cpu/cpufreq/boost 2. offline one CPU: echo 0 > /sys/devices/system/cpu/cpuX/online 3. deboost all CPUs: echo 0 > /sys/devices/system/cpu/cpufreq/boost 4. online CPUX: echo 1 > /sys/devices/system/cpu/cpuX/online 5. boost all CPUs again: echo 1 > /sys/devices/system/cpu/cpufreq/boost This is because max_freq_req of the policy is not updated during the online process, and the value of max_freq_req before the last offline is retained. When the CPU is boosted again, freq_qos_update_request() will do nothing because the old value is the same as the new one. This causes the CPU to stay at the base frequency. Updating max_freq_req in cpufreq_online() will solve this problem. Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Link: https://patch.msgid.link/20250117101457.1530653-2-zhenglifeng1@huawei.com [ rjw: Subject and changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Xinghai Cen <cenxinghai@h-partners.com> Signed-off-by: Qi Xi <xiqi2@huawei.com> --- drivers/cpufreq/cpufreq.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 717eedd7868e..99fa68e530ae 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1476,6 +1476,10 @@ static int cpufreq_online(unsigned int cpu) blocking_notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_CREATE_POLICY, policy); + } else { + ret = freq_qos_update_request(policy->max_freq_req, policy->max); + if (ret < 0) + goto out_destroy_policy; } if (cpufreq_driver->get && has_target()) { -- 2.33.0