linux-kernel - [PATCH 2/5] cpufreq: intel_pstate: Migrate to ->exit() callback instead of ->stop

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Date:   Thu, 10 Jun 2021 13:53:58 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Rafael Wysocki <rjw@...ysocki.net>,
        Qian Cai <quic_qiancai@...cinc.com>,
        Srinivas Pandruvada <srinivas.pandruvada@...ux.intel.com>,
        Len Brown <lenb@...nel.org>,
        Viresh Kumar <viresh.kumar@...aro.org>
Cc:     linux-pm@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Ionela Voinescu <ionela.voinescu@....com>,
        Dirk Brandewie <dirk.j.brandewie@...el.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 2/5] cpufreq: intel_pstate: Migrate to ->exit() callback instead of ->stop_cpu()

commit 367dc4aa932b ("cpufreq: Add stop CPU callback to cpufreq_driver
interface") added the stop_cpu() callback to allow the drivers to do
clean up before the CPU is completely down and its state cannot be
modified.

At that time the CPU hotplug framework used to call the cpufreq core's
registered notifier for different events like CPU_DOWN_PREPARE and
CPU_POST_DEAD. The stop_cpu() callback was called during the
CPU_DOWN_PREPARE event.

This is no longer the case, cpuhp_cpufreq_offline() is called only once
by the CPU hotplug core now and we don't really need two separate
callbacks for cpufreq drivers, i.e. stop_cpu() and exit(), as everything
can be done from the exit() callback itself.

Migrate to using the exit() callback instead of stop_cpu().

Cc: Dirk Brandewie <dirk.j.brandewie@...el.com>
Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
---
 drivers/cpufreq/intel_pstate.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c
index f0401064d7aa..9d3191663925 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -2374,17 +2374,11 @@ static int intel_pstate_cpu_online(struct cpufreq_policy *policy)
 	return 0;
 }
 
-static void intel_pstate_stop_cpu(struct cpufreq_policy *policy)
-{
-	pr_debug("CPU %d stopping\n", policy->cpu);
-
-	intel_pstate_clear_update_util_hook(policy->cpu);
-}
-
 static int intel_pstate_cpu_exit(struct cpufreq_policy *policy)
 {
 	pr_debug("CPU %d exiting\n", policy->cpu);
 
+	intel_pstate_clear_update_util_hook(policy->cpu);
 	policy->fast_switch_possible = false;
 
 	return 0;
@@ -2451,7 +2445,6 @@ static struct cpufreq_driver intel_pstate = {
 	.resume		= intel_pstate_resume,
 	.init		= intel_pstate_cpu_init,
 	.exit		= intel_pstate_cpu_exit,
-	.stop_cpu	= intel_pstate_stop_cpu,
 	.offline	= intel_pstate_cpu_offline,
 	.online		= intel_pstate_cpu_online,
 	.update_limits	= intel_pstate_update_limits,
-- 
2.31.1.272.g89b43f80a514