cpufreq: Introduce a more generic way to set default per-policy boost flag

In cpufreq_online() of cpufreq.c, the per-policy boost flag is already
set to mirror the cpufreq_driver boost during init but using freq_table
to judge if the policy has boost frequency. There are two drawbacks to
this approach:

 1. It doesn't work for the cpufreq drivers that do not use a frequency
    table. For now, acpi-cpufreq and amd-pstate have to enable boost in
    policy initialization. And cppc_cpufreq never set policy to boost
    when going online no matter what the cpufreq_driver boost flag is.

 2. If the CPU goes offline when cpufreq_driver boost is enabled and
    then goes online when cpufreq_driver boost is disabled, the
    per-policy boost flag will incorrectly remain true.

Running set_boost at the end of the online process is a more generic way
for all cpufreq drivers.

Signed-off-by: Lifeng Zheng <zhenglifeng1@huawei.com>
Link: https://patch.msgid.link/20250117101457.1530653-3-zhenglifeng1@huawei.com
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 4d54e30f94ee1500049d3bd0f205059a76450f89..e0048856eceee868792245594741743fe9231a46 100644 (file)
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1410,10 +1410,6 @@ static int cpufreq_online(unsigned int cpu)
                        goto out_free_policy;
                }
 
-               /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
-               if (cpufreq_boost_enabled() && policy_has_boost_freq(policy))
-                       policy->boost_enabled = true;
-
                /*
                 * The initialization has succeeded and the policy is online.
                 * If there is a problem with its frequency table, take it
@@ -1574,6 +1570,18 @@ static int cpufreq_online(unsigned int cpu)
        if (new_policy && cpufreq_thermal_control_enabled(cpufreq_driver))
                policy->cdev = of_cpufreq_cooling_register(policy);
 
+       /* Let the per-policy boost flag mirror the cpufreq_driver boost during init */
+       if (policy->boost_enabled != cpufreq_boost_enabled()) {
+               policy->boost_enabled = cpufreq_boost_enabled();
+               ret = cpufreq_driver->set_boost(policy, policy->boost_enabled);
+               if (ret) {
+                       /* If the set_boost fails, the online operation is not affected */
+                       pr_info("%s: CPU%d: Cannot %s BOOST\n", __func__, policy->cpu,
+                               policy->boost_enabled ? "enable" : "disable");
+                       policy->boost_enabled = !policy->boost_enabled;
+               }
+       }
+
        pr_debug("initialization complete\n");
 
        return 0;