releases/5.10.50/cpufreq-make-cpufreq_online-call-driver-offline-on-e.patch

From 96c150ab868a54ea2d20cc718f68de53dadfb3a8 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Tue, 22 Jun 2021 21:11:39 +0200
Subject: cpufreq: Make cpufreq_online() call driver->offline() on errors

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

[ Upstream commit 3b7180573c250eb6e2a7eec54ae91f27472332ea ]

In the CPU removal path the ->offline() callback provided by the
driver is always invoked before ->exit(), but in the cpufreq_online()
error path it is not, so ->exit() is expected to somehow know the
context in which it has been called and act accordingly.

That is less than straightforward, so make cpufreq_online() invoke
the driver's ->offline() callback, if present, on errors before
->exit() too.

This only potentially affects intel_pstate.

Fixes: 91a12e91dc39 ("cpufreq: Allow light-weight tear down and bring up of CPUs")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/cpufreq/cpufreq.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c
index 1e7e3f2ff09f..ebee0ad559fa 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -1368,9 +1368,14 @@ static int cpufreq_online(unsigned int cpu)
 			goto out_free_policy;
 		}
 
+		/*
+		 * The initialization has succeeded and the policy is online.
+		 * If there is a problem with its frequency table, take it
+		 * offline and drop it.
+		 */
 		ret = cpufreq_table_validate_and_sort(policy);
 		if (ret)
-			goto out_exit_policy;
+			goto out_offline_policy;
 
 		/* related_cpus should at least include policy->cpus. */
 		cpumask_copy(policy->related_cpus, policy->cpus);
@@ -1513,6 +1518,10 @@ out_destroy_policy:
 
 	up_write(&policy->rwsem);
 
+out_offline_policy:
+	if (cpufreq_driver->offline)
+		cpufreq_driver->offline(policy);
+
 out_exit_policy:
 	if (cpufreq_driver->exit)
 		cpufreq_driver->exit(policy);
-- 
2.30.2